Biofuel cells Research Papers - Academia.edu (original) (raw)

2025

We are describing a new optimized method for the preparation of single-sized crystalline lead sulphide (PbS) nanoparticles (NPs). The optimized solvothermal method uses a mixture of octadecene and oleic acid as a reaction media and MBTS as a reducing agent. Systematic investigation was performed on various synthesis parameters, such as acid to lead (Pb) and lead to sulphur(S) feed molar ratios, feed amounts of various phosphine compounds, reducing agent, total concentrations of reaction media, growth temperature, as well as different sulphur source compounds. We optimized the amount of 2,2-dithiobis(benzothiazole) (MBTS) in the reaction mixture to produce about 100 nm size and spherical shape zinc blade type PbS NPs. A broad UV absorption spectrum was observed when the MBTS amount was increased in the reaction mixture. The excellent organic solvent dispersion properties, along with near-IR emission spectrum window make these NPs a great choice in optoelectronics applications, especially for photovoltaic devices.

2025

Companies who make or handle non-Newtonian liquids are challenged with finding a suitable process control method that can inform the process operators and control system about the current rheological properties of the liquids being processed. A range of high quality in-line viscometers are available, but commercial instruments are unable to monitor complex rheology, like viscoelasticity in real time. We introduce a novel measurement principle that allow for automatic, continuous near-real-time rheology monitoring. The method is based on the detection of a specific differential pressure when the liquid flows through a complexly shaped channel. This pressure difference can be related to the complex rheology of the liquid. The method, currently being prototyped, has been applied for measuring viscoelasticity in a range of different liquids, such as food stabilizers and liquid detergents, and we discuss the potential application in an industrial context.

2024, Journal of Power Sources

2,6-Pyridinedicarboxylic acid is a useful electron mediator for glucose oxidase. 2,6-Pyridinedicarboxylic acid and glucose oxidase were assembled on gold electrode. In presence of the mediator, glucose oxidation occur 461 mV earlier. The... more

2024, Sensors

Dehydrogenase based bioelectrocatalysis has been increasingly exploited in recent years in order to develop new bioelectrochemical devices, such as biosensors and biofuel cells, with improved performances. In some cases, dehydrogeases are able to directly exchange electrons with an appropriately designed electrode surface, without the need for an added redox mediator, allowing bioelectrocatalysis based on a direct electron transfer process. In this review we briefly describe the electron transfer mechanism of dehydrogenase enzymes and some of the characteristics required for bioelectrocatalysis reactions via a direct electron transfer mechanism. Special attention is given to cellobiose dehydrogenase and fructose dehydrogenase, which showed efficient direct electron transfer reactions. An overview of the most recent biosensors and biofuel cells based on the two dehydrogenases will be presented. The various strategies to prepare modified electrodes in order to improve the electron transfer properties of the device will be carefully investigated and all analytical parameters will be presented, discussed and compared.

2024, ChemPhysChem

Interdisciplinary research has combined the efforts of many scientists and engineers to gain an understanding of biotic and abiotic electrochemical processes, materials properties, biomedical, and engineering approaches for the development of alternative power‐generating and/or energy‐harvesting devices, aiming to solve health‐related issues and to improve the quality of human life. This review intends to recapitulate the principles of biofuel cell development and the progress over the years, thanks to the contribution of cross‐disciplinary researchers that have combined knowledge and innovative ideas to the field. The emergence of biofuel cells, as a response to the demand of electrical power devices that can operate under physiological conditions, are reviewed. Implantable biofuel cells operating inside living organisms have been envisioned for over fifty years, but few reports of implanted devices have existed up until very recently. The very first report of an implanted biofuel ...

2024, Langmuir

The purified photosynthetic reaction center protein (RC) from Rhodobacter sphaeroides R-26 purple bacteria was bound to porous silicon microcavities (PSiMc) either through silane-glutaraldehyde (GTA) chemistry or via a noncovalent peptide cross-linker. The characteristic resonance mode in the microcavity reflectivity spectrum red shifted by several nanometers upon RC binding, indicating the protein infiltration into the porous silicon (PSi) photonic structure. Flash photolysis experiments confirmed the photochemical activity of RC after its binding to the solid substrate. The kinetic components of the intraprotein charge recombination were considerably faster (τ fast = 14 (±9) ms, τ slow = 230 (±28) ms with the RC bound through the GTA cross-linker and only τ fast = 27 (±3) ms through peptide coating) than in solution (τ fast = 120 (±3) ms, τ slow = 1387 (±2) ms), indicating the effect of the PSi surface on the light-induced electron transfer in the protein. The PSi/RC complex was found to oxidize the externally added electron donor, mammalian cytochrome c, and the cytochrome oxidation was blocked by the competitive RC inhibitor, terbutryne. This fact indicates that the specific surface binding sites on the PSi-bound RC are still accessible to external cofactors and an electronic interaction with redox components in the aqueous environment is possible. This new type of biophotonic material is considered to be an excellent model for new generation applications at the interface of silicon-based electronics and biological redox systems designed by nature.

2024

— An Enzymatic biofuel cell is a specific type of fuel cell which uses enzymes as catalysts to oxidize its fuel. Because of their efficient size and immobility, they pose as a great promise in terms of their relatively inexpensive components and fuels, as well as a potential power source for bionic implants. Here, we present the use of dry-etched nanotextured porous silicon scaffolds as a basis for new biofuel designs. Such an architecture increases the contact surface area of silicon with surrounding biofuel to enhance the process of harvesting of energy, and consequently, the efficiency of the cell. Keywords-nanotechnology; porous silicon; biofuel cell I.

2024, Biotechnology Letters

Objective Oleaginous yeasts are a renewable and alternative source of oil for third-generation biodiesel. This work aimed to evaluate the effects of glucose concentration (30-100 g L -1 ) on growth, lipid synthesis, and fatty acids (FA) profile of three Rhodotorula spp. (R. glacialis R15, R. glutinis R4, and R. glutinis R48) isolated from Antarctica, and estimate the key quality parameters of the biodiesel produced by yeasts to confirm their potential as feedstocks for third-generation biodiesel synthesis. Results Yeasts accumulated 50-69.5% of lipids (w/ w) under nitrogen-limitation and glucose-excess (C/ N = 40-133). Glucose concentration increase influenced positively lipid accumulation (69.5% w/w) and FA profile of R. glacialis R15. Lipid accumulation (53% on average) of R. glutinis strains was not significantly affected by glucose concentration; content of saturated (* 30%) and polyunsaturated FA (* 29-30%) was slightly influenced. FA profiles of lipids synthesized by R15, R4, and R48 are similar to vegetable oils used in biodiesel industry with C16 and C18 FA (95-99%) as the major components, and contain mainly oleic (C18:1), palmitic (C16:0), and linoleic (C18:2) acids, which are suitable for biodiesel synthesis. Estimated fuel properties for biodiesel produced by R15, R4, and R48 satisfied all the criteria established by ASTM D6751 and EN 14214 with good cetane number, iodine value, and oxidation stability. An improvement in biodiesel quality of R15 was observed with the glucose increase. The best global properties of biodiesel from R4 were obtained with 30 g L -1 of glucose.

2024

Electricity generation in a duel chamber microbial fuel cell (MFC) consisting of graphite anode electrode, platinum cathode electrode and Nafion 117 membrane was investigated. Anaerobic sludge was used as the source of microorganisms in the anode chamber. Acetic acid as the sole carbon source along with other nutrients was added to the anode chamber in a batch or repeated-batch modes. System curves and polarization curves were obtained in different operational conditions and the internal resistance of the system was calculated. Electricity generation by MFC in both batch and repeatedbatch modes was modeled using a biofilm based hypothesis and the results were compared with experimental data.

2024, Curr Sci

One type of genuine fuel cell that does hold promise in the long-term is the biological fuel cell. Unlike conven-tional fuel cells, which employ hydrogen, ethanol and methanol as fuel, biological fuel cells use organic pro-ducts produced... more

2024

Submitted for the NWS11 Meeting of The American Physical Society Temperature and Pore Size Dependence of a Nanoporous Platinum Based Hydrogen Senor1 ADITYA ABBURI, HAROLD FAIRWEATHER JR., WEI JIANG YEH, University of Idaho — In this study, hydrogen sensing properties of nanoporous Pt films have been investigated for different pore sizes at various temperatures (25–100 ̊C) and hydrogen concentrations (100– 1000ppm). The nanoporous thin films were fabricated by a method of cosputtering, dealloying and coarsening. CuxPt1−x thin films of thickness 150nm were formed by magnetron sputtering of Cu and Pt. These films were dealloyed in concentrated sulfuric acid to remove Cu. Coarsening of the dealloyed films at various temperatures produced nanoporous Pt thin films of different pore sizes. The morphologies of the nanoporous Pt films were studied by Scanning Electron Microscopy (SEM). Hydrogen sensing properties of the nanoporous Pt film were measured using a resistance transient method. It...

2024

this study, hydrogen sensing properties of nanoporous Pt films have been investigated for different pore sizes at various temperatures (25-100˚C) and hydrogen concentrations (100-1000ppm). The nanoporous thin films were fabricated by a method of cosputtering, dealloying and coarsening. Cu x Pt 1−x thin films of thickness 150nm were formed by magnetron sputtering of Cu and Pt. These films were dealloyed in concentrated sulfuric acid to remove Cu. Coarsening of the dealloyed films at various temperatures produced nanoporous Pt thin films of different pore sizes. The morphologies of the nanoporous Pt films were studied by Scanning Electron Microscopy (SEM). Hydrogen sensing properties of the nanoporous Pt film were measured using a resistance transient method. It was found that the sensor response of the nanoporous Pt films was approximately 3.5% at 1000ppm H 2 for a pore size of 35nm at room temperature. The detection limit was lower than 100 ppm at room temperature and the sensor showed repeatability.

2024, Biochimica et Biophysica Acta (BBA) - Bioenergetics

Oxygenic photosynthesis is driven via sequential action of Photosystem II (PSII) and (PSI)reaction centers via the Z-scheme. Both of these pigment-membrane protein complexes are found in cyanobacteria, algae, and plants. Unlike PSII, PSI is remarkably stable and does not undergo limiting photo-damage. This stability, as well as other fundamental structural differences, makes PSI the most attractive reaction centers for applied photosynthetic applications. These applied applications exploit the efficient light harvesting and high quantum yield of PSI where the isolated PSI particles are redeployed providing electrons directly as a photocurrent or, via a coupled catalyst to yield H 2. Recent advances in molecular genetics, synthetic biology, and nanotechnology have merged to allow PSI to be integrated into a myriad of biohybrid devices. In photocurrent producing devices, PSI has been immobilized onto various electrode substrates with a continuously evolving toolkit of strategies and novel reagents. However, these innovative yet highly variable designs make it difficult to identify the rate-limiting steps and/or components that function as bottlenecks in PSI-biohybrid devices. In this study we aim to highlight these recent advances with a focus on identifying the similarities and differences in electrode surfaces, immobilization/orientation strategies, and artificial redox mediators. Collectively this work has been able to maintain an annual increase in photocurrent density (A cm −2) of~10-fold over the past decade. The potential drawbacks and attractive features of some of these schemes are also discussed with their feasibility on a large-scale. As an environmentally benign and renewable resource, PSI may provide a new sustainable source of bioenergy.

2024, Journal of Electroanalytical Chemistry

We report a new approach to fabricate an efficient 3D glucose bioanode based on the coimmobilization of the enzyme glucose dehydrogenase (GDH), its cofactor NADP, and Multiwall Carbon Nanotubes (MWCNTs) coated with poly (Methylene Green) (PMG). The MWCNT-PMG composite was obtained by chemical polymerization of Methylene Green (MG) monomer on the MWCNT surfaces. Structural and chemical analyses clearly showed successful coating of the MWCNTs with PMG that markedly affected their morphological and surface charge properties. Electrochemical investigation of PMG-MWCNTs mixed with GDH and NADP showed high stability with extended bioanode electrocatalytic activity towards glucose oxidation for more than one year.

2024, Water Science and Technology

Microbial fuel cells (MFCs) are emerging as promising technology for the treatment of wastewaters. The potential energy conversion efficiencies are examined. The rates of energy recovery (W/m3 reactor) are reviewed and evaluated. Some recent data relating to potato-processing wastewaters and a hospital wastewater effluent are reported. Finally, a set of process configurations in which MFCs could be useful to treat wastewaters is schematized. Overall, the MFC technology still faces major challenges, particularly in terms of chemical oxygen demand (COD) removal efficiency.

2024, Radioelectronics. Nanosystems. Information Technologies

This review deals with the use of the highly conductive polymer PEDOT:PSS in biomedical and bioelectrochemical systems. The examples of toxic effects on living cells, positive effects of PEDOT:PSS on the viability of cells and tissues are given. The properties of the polymer, methods of increasing its electrical conductivity by its modification with various nanoparticles and nanomaterials are discussed. Examples of using PEDOT and its composites in bioelectrochemical devices, such as biosensors and biofuel cells, are considered. Changes in the characteristics of biosensors and biofuel cells under the influence of PEDOT are discussed.

2024, Journal of Power Sources

Here, we report a comparative study on the kinetic activity of various anodes of a recently described microbial fuel cell consisting of an anode imbedded in marine sediment and a cathode in overlying seawater. Using plain graphite anodes, it was demonstrated that a significant portion of the anodic current results from oxidation of sediment organic matter catalyzed by microorganisms colonizing the anode and capable of directly reducing the anode without added exogenous electron-transfer mediators. Here, graphite anodes incorporating microbial oxidants are evaluated in the laboratory relative to plain graphite with the goal of increasing power density by increasing current density. Anodes evaluated include graphite modified by adsorption of anthraquinone-1,6-disulfonic acid (AQDS) or 1,4-naphthoquinone (NQ), a graphite-ceramic composite containing Mn 2+ and Ni 2+ , and graphite modified with a graphite paste containing Fe 3 O 4 or Fe 3 O 4 and Ni 2+. It was found that these anodes possess between 1.5and 2.2-fold greater kinetic activity than plain graphite. Fuel cells were deployed in a coastal site near Tuckerton, NJ (USA) that utilized two of these anodes. These fuel cells generated ca. 5-fold greater current density than a previously characterized fuel cell equipped with a plain graphite anode, and operated at the same site.

2024, Journal of Electroanalytical Chemistry

In this work we report on the photocurrent increasing obtained by using thylakoid membranes "wired" with an osmium redox polymer (OsRP) immobilized onto screen-printed carbon and gold electrodes (SPCEs and SPAuEs), modified with gold microparticles (AuMPs) and gold nanoparticles (AuNPs). Both AuMPs and AuNPs were electrodeposited by using the same electrodeposition method, in order to study the influence of different electrode surface morphologies, namely AuMPs and AuNPs, on the photocurrent generated when illuminated with light with an intensity equivalent to that of sunlight (400 Wm-2). AuMPs/SPCEs showed the highest current density (62.5 µA cm-2) upon illumination probably due to a higher capacitive current directly related to the enhanced electroactive area (A EA) and roughness factor (). Finally, the so modified electrodes AuMPs/SPCE and AuNPs/SPAuE were characterized by using scanning electron microscopy (SEM) showing a different surface morphology, resulting in a higher surface roughness for AuMPs/SPCE compare to AuNPs/SPAuE therefore an intimate interaction between the large thylakoid membrane and the AuNPs. A high photocurrent density of 62.5 µA cm-2 was generated at a light intensity of 400 Wm-2 .

2024, ChemElectroChem

Biological photovoltaics (BPVs) are emerging as a potential sustainable energy-generating technology to convert solar energy into electrical energy. Although a great variety of photosynthetic biomaterials were studied in BPVs, cyanobacteria are considered as superior candidates because of their simpler physiology. To facilitate extracellular electron transfer (EET) from cyanobacteria to electrodes is the greatest challenge to improving the performance of BPVs. However, a systematic study comparing the photo-excited EET from such organisms is not yet reported. Here we report on a comparison of photocurrent density generated by benthic cyanobacteria, that is, two species of Leptolyngbya sp. (CAWBG62 and CAWBG100), one species from the order Chroococcales (CAWBG64), and a eukaryotic algae, Paulschulzia pseudovolvox (UKE). This algae and CAWBG100 were sourced from New Zealand, CAWBG62 and CAWBG64 were from Antarctica. We demonstrate EET mediated by three different electron transfer (ET) mediating systems on graphite electrodes. These are as follows: (I) [Os(2,2'-(bipyridine) 2 (polyvinyl-imidazole) 10 Cl] + /2 + (1:9) [Os-(bpy)PVI] (II) p-benzoquinone (PBQ) (III) [Os-(bpy)PVI] together with PBQ. The maximum photocurrent density of 47.2 mA cm À2 was obtained from CAWBG64 mediated by (III) [Os-(bpy)PVI] together with PBQ.

2024, Advanced Energy Materials

Scheme 1. Schematic representation of a supercapacitive biosolar cell during the charging process. Yellow rectangles, gold support; orange spheres, gold nanoparticles; brown rectangle, osmium redox polymer; green globules, bilirubin oxidase; TMs, thylakoid membranes; SCP, solar energy converting part; ORP, oxygen reducing part; CSC, charge storing components of bioelectrodes.

2024, Electroanalysis

Gluconobacter oxydans (G. oxydans) cells together with an osmium redox polymer (ORP) [Osmium (2,2'-bipyridine)2(poly-vinylimidazole)10Cl]Cl were combined with a glassy carbon paste electrode (GCPE) to form a bioanode for a microbial fuel cell (MFC) based on G. oxydans. Although there are G.oxydans/ ORP combined bioanode in the literature, as far as it is known, this system is the first one where G.oxydans/ORP bioanode is combined with a cathode and a MFC is formed. After the optimization of experimental parameters, analytical characteristics of ORP/G. oxydans/GCPE bioanode were investigated. ORP/G. oxydans/GCPE showed two linear ranges for ethanol substrate as 1.0-30 mM (R 2 = 0.902) and 30-500 mM (R 2 = 0.997) and analytical range as 1.0-1000 mM. Limit of detection (3.0 s/m) and limit of quantification (10 s/m) values were calculated as 1.29 mM and 4.30 mM respectively where the RSD value was 1.16 % for n = 5. Combining the developed bioanode in the presence of 5.0 mM K 3 Fe(CN) 6 mediator with a Pt wire cathode a double compartment MFC was obtained via a salt bridge. G. oxydans/GCPE bioanode based MFC had maximum power density of 0.133 mW cm À2 (at 33.5 mV), maximum current density as 8.73 mA cm À2 and OCP value of 156 mV. On the other hand, ORP/G. oxydans/ GCPE based MFC showed maximum power density as 0.26 mW cm À2 (at 46.8 mV), maximum current density as 15.079 mA cm-2 and OCP value of 176 mV.

2024, Electrochimica Acta

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2024, ACS applied materials & interfaces

Controlling the interface between biological tissues and electrodes remains an important challenge for the development of implantable devices in terms of electroactivity, biocompatibility, and long-term stability. To engineer such a biocompatible interface a low molecular weight gel (LMWG) based on a glycosylated nucleoside fluorocarbon amphiphile (GNF) was employed for the first time to wrap gold electrodes via a noncovalent anchoring strategy, that is, self-assembly of GNF at the electrode surface. Scanning electron microscopy (SEM) studies indicate that the gold surface is coated with the GNF hydrogels. Electrochemical measurements using cyclic voltammetry (CV) clearly show that the electrode properties are not affected by the presence of the hydrogel. This coating layer of 1 to 2 μm does not significantly slow down the mass transport through the hydrogel. Voltammetry experiments with gel coated macroporous enzyme electrodes reveal that during continuous use their current is impr...

2024, Journal of the American Chemical Society

2024, The European Physical Journal Special Topics

A new method for the elaboration of a novel type of catalytic microsystem with a high specific area catalyst is developed. A silver nanocluster catalytic microreactor was elaborated by doping a sodalime glass with a silver salt. By applying a high power laser beam to the glass, silver nanoclusters are obtained at one of the surfaces which were characterized by BET measurements and AFM. A microfluidic chip was obtained by sealing the silver coated glass with a NOA 81 microchannel. The catalytic activity of the silver nanoclusters was then tested for the efficiency of water purification by using catalytic ozonation to oxidize an organic pollutant. The silver nanoclusters were found to be very stable in the microreactor and efficiently oxidized the pollutant, in spite of the very short residence times in the microchannel. This opens the way to study catalytic reactions in microchannels without the need of introducing the catalyst as a powder or manufacturing complex packed bed microreactors.

2024, International Journal of Nanotechnology

The use of microchannels for catalytic reactions represents a considerable experimental opportunity, because of the high surface area to volume ratio these devices typically have. However, incorporating catalysts into microfluidic devices has proven technically challenging. We report the development of a new type of microfluidic device that has a catalytically active metal surface with a large active area built into one of the walls that constitute the microchannel. We test the catalytical activity on an important chemical reaction for drinking water purification: the catalytic ozonation of a typical organic pollutant that is otherwise difficult to remove from the water. pCBA was chosen as model pollutant since it is known to have slow reaction rates with molecular ozone and hence to pose problems in water purification. We find that the catalytic microreactor increases the overall reaction rate by a factor 350 compared to the bulk reaction, owing to both the catalytic activity and the confinement, and is thus highly efficient even for very short residence times.

2024, Electrochemistry Communications

The fabrication of bioelectrocatalytic protein electrodes by the simple compression of carbon nanotube and protein powders was investigated using a series of proteins including bilirubin oxidase (BOx), bovine serum albumin (BSA), catalase, cytochrome C (Cyt C), diaphorase, FAD-dependent glucose dehydrogenase (FAD-GDH), galactose oxidase (GAOx), glucose oxidase (GOx), horseradish peroxidase (HRP), laccase and urease. The isoelectric points (pI) of the proteins ranged from 3.5 to 12 and the molecular weights ranged from 12.4 to 480 kDa. The compression of diaphorase, laccase, BOx, FAD-GDH, catalase and urease gave mechanically stable biopellets in 0.1 M phosphate buffer pH 7.4. For Cyt C, BSA, GAOx, GOx, and HRP, contact with buffer destabilised the biopellet and induced a fast destruction of the composite. In parallel, stable redox pellets were obtained with differently charged redox mediators: hexaammineruthenium (III) chloride, potassium hexacyanoferrate or 1,4-naphthoquinone. Several parameters were explored to shed new light on the factors that determine biopellet stability. Stable biopellets capable of direct and mediated electron transfer were subsequently elaborated, for O 2 reduction and glucose oxidation, respectively, based on the simplified procedure that does not require stabilising protection membranes or holders on the contrary to existing methods.

2024, Electrochimica Acta

The field of biophotoelectrochemistry and its application in biophotovoltaics and biosensors has gained more and more attention in recent years. Knowledge of the redox potentials of the catalytically active protein cofactors in biophotovoltaic devices is crucial for accurate modelling and in discerning the mechanisms of their operation. Here, for the first time, we used spectroelectrochemical methods to investigate thermodynamic parameters of a biophotoelectrode in situ. We determined redox potentials of two elements of the system: the primary electron donor in photosynthetic reaction centers (RCs) of the bacterium Rhodobacter sphaeroides and osmium-complex based redox mediators that are bound to a hydrogel matrix. We observe that the midpoint potential of the primary donor is shifted towards more positive potentials in comparison to literature data for RCs solubilized in buffered water solution, likely due to interaction with the polymer matrix. We also demonstrate that the osmium-complex modified redox polymer efficiently wires the RCs to the electrode, maintaining a high Internal Quantum Efficiency with approximately one electron per two photons generated (IQE ¼ 50±12%). Overall, this biophotoelectrode may be attractive for controlling the redox state of the protein when performing other types of experiments, e.g. time resolved absorption or fluorescence measurements, in order to gain insights into kinetic limitations and thereby help in the rational design of bioelectronic devices.

2024, Energy Procedia

A two phases model of air heating in bubbling fluidized bed of sand particles with concentrated solar radiation as source of energy is developed. This model is based on the Kato and Wen's model (1969) for the hydrodynamic aspect which was modified to take account the thermic aspect. Nine algebraic equations were established in permanent regime for different heat and mass balances as well as heat losses against surrounding media. The Newton Raphson's method was used to solve this system of equations. Results have shown that the model developed is able to predict the temperature profiles of gas and particles in the bubble and emulsion phases, the wall temperature along the reactor, the heat flux transferred to the bed and heat losses by forced convection and radiation to surrounding air. The effects of the fluidizing air velocity, total mass of particles and the wind velocity on the thermal behaviours were examined. Model predictions seem reasonable looking for its comparison agreement with bibliographical data.

2024, Scientific reports

Pristine titanium dioxide (TiO2) absorbs ultraviolet light and reflects the entire visible spectrum. This optical response of TiO2 has found widespread application as white pigments in paper, paints, pharmaceuticals, foods and plastic industries; and as a UV absorber in cosmetics and photocatalysis. However, pristine TiO2 is considered to be inert under visible light for these applications. Here we show for the first time that a bacterial contaminant (Staphylococcus aureus-a MRSA surrogate) in contact with TiO2 activates its own photocatalytic degradation under visible light. The present study delineates the critical role of visible light absorption by contaminants and electronic interactions with anatase in photocatalytic degradation using two azo dyes (Mordant Orange and Procion Red) that are highly stable because of their aromaticity. An auxiliary light harvester, polyhydroxy fullerenes, was successfully used to accelerate photocatalytic degradation of contaminants. We designed a...

2024, Physical chemistry chemical physics : PCCP

Photosynthetic microbial fuel cells (PMFCs) are an emerging technology for renewable solar energy conversion. Major efforts have been made to explore the electrogenic activity of cyanobacteria, mostly using practically unsustainable reagents. Here we report on photocurrent generation (≈8.64 μA cm(-2)) from cyanobacteria immobilized on electrodes modified with an efficient electron mediator, an Os(2+/3+) redox polymer. Upon addition of ferricyanide to the electrolyte, cyanobacteria generate the maximum current density of ≈48.2 μA cm(-2).

2024, European Journal Of Pharmaceutical And Medical Research

Bimatoprost (BMT) is novel prostaglandin analogue, chemically related to prostamide F2α useful in eye glaucoma ocular disorder. BMT is optically active due to the presence of chiral centers and exhibit Cis (Z) to Trans (E) isomerism which prompted chiral impurities in bulk drug.These impurities will be carry forward to drug product. In the present study, a simple and economic reversed phase HPLC method was developed for analysis of the BMT and it known chiral impurities in drug substance and drug product. The optimized separation was performed on X-Bridge C18 150mm x 4.6mm, 3.5µ column with isocratic elution by maintaining column temperature at 40 ºC. The mobile phase consisted a simple mixture of water, methanol and acetic acid in the rationof 52:48:01 v/v/v. Detection of analytes was conducted on 210. The stability indicating capability of this method was demonstrated by carrying out forced degradation studies. BMT underwent significant degradation when subjected to acidic and oxidative environment, while BMT is stable in alkali, thermal and photolytic degradation. The degradant did not interfere with BMT and its impurity which is proven by peak purity of each peaks. The performance of this method was validated in accordance to the regulatory guidelines recommended by the International Conference of Homonization (ICH). The stability indicating proposed method in this paper could be applied for process development as well as quality assurance of BMT bulk drug and ophthalmic solution.

2024, Applied Photosynthesis - New Progress

Oxygenic photosynthesis is a process of light energy conversion into the chemical energy using water and carbon dioxide. The efficiency of energy conversion in the primary processes of photosynthesis is close to 100%. Therefore, for many years, photosynthesis has attracted the attention of researchers as the most efficient and ecofriendly pathway of solar energy conversion for alternative energy systems. The recent advances in the design of optimal solar cells include the creation of converters, in which thylakoid membranes, photosystems and whole cells of cyanobacteria immobilized on nanostructured electrode are used. As the mechanism of solar energy conversion in photosynthesis is sustainable and environmentally safe, it has a great potential as an example of renewable energy device. Application of pigments such as Chl f and Chl d will extend the spectral diapason of light transforming systems allow to absorb the farred and near infra-red photons of the spectrum (in the range 700-750 nm). This article presents the recent achievements and challenges in the area of solar cells based on photosynthetic systems.

2024, Biosensors and Bioelectronics

A biofuel cell, consisting of two 3 mm diameter carbon rod electrodes and operating at ambient temperature in aqueous solution, pH 6, is described. Biofuel cell based on enzymes able to exchange directly electrons with carbon electrodes was constructed and characterized. Anode of the biofuel cell was based on immobilized Quino-hemoprotein alcohol dehydrogenase from Gluconobacter sp. 33 (QH-ADH), cathode on co-immobilized glucose oxidase from Aspergilus niger (GO x) and microperoxidase 8 from the horse heart (MP-8) acting in the consecutive mode. Two enzymes GO x and MP-8 applied in the design of biofuel cell cathode were acting in consecutive mode and by hydrogen peroxide oxidized MP-8 was directly accepting electrons from carbon rod electrode. If ethanol was applied as an energy source the maximal open circuit potential of the biofuel cell was −125 mV. If glucose was applied as energy source the open circuit potential of the cell was +145 mV. The maximal open circuit potential (270 mV) was achieved in the presence of extent concentration (over 2 mM) of both substrates (ethanol and glucose). Operational half-life period (τ 1/2) of the biofuel cell was found to be 2.5 days.

2024, International Journal of Innovative Research and Development

Introduction Oil crisis of 1973 and Energy crisis of 1979 have provided initial impetus for the world to seek alternatives to energy from fossil sources. Countries like Brazil and other developed nations have become increasingly dependent on green oil at a time of rising and volatile fuel prices like this, in the industry, transport system and even domestically. Other developing nations, like Nigeria should not be a let out in the search for alternative energy sources, more so that there is sudden alarming hike in petroleum prices by the current administration due to sharp drop in the price of crude oil per barrel in the world market-the shock is a big hit for the nation as she is always known for her monoculture economy. In view of the depleting oil reserves and exponential rise in population demand for petroleum products, the search for alternative sources of fuel is very timely and important. The search for a cleaner and more secure energy source is a boon to any economy, particularly the developing ones. One of the most reliable alternative fuels which can be quickly integrated into existing transport structure is biodiesel from non-edible oil seeds like Jatropha Curcas Lini (JCL). According to Anjan et al (2009), since the 1970s, the world's attention has been focused on depleting oil reserves, rising demand for petroleum products and consequent hike in petroleum prices. Empirical facts gathered reveal that the price of crude oil will remain increasing and volatile for a long time to come if there are no alternatives to cater for this rising demand from the teeming population. For instance, in Nigeria, 1 litre of kerosene is now sold for ₦130 as at present as against ₦50 in the recent past. This is rather unaffordable for people living below poverty line in the remote areas, considering their per capital income in a day. Sambo (2008) reported that Jathropha is a cheap and abundant alternative raw material for biodiesel production that poses no risk to global food security. The report also revealed that "the global crisis is directly linked to maize, sugarcane, cassava and other edible energy crops conversion to ethanol for biofuel because these are direct food items to a large number of the world population". In other word, the competition posed by the use of food crops as energy crop will reduce if focus is shifted to use of non-edibles like Jathropha oil crop as energy crop for biofuel production.

2024, Catalysts

The release of substantial amounts of toxicologically significant, irritant, and malodourous compounds during the complete combustion of tobacco can generate an unpleasant environment, especially indoors. Herein, we developed non-woven fabric-supported UV-and visible-light-responsive photocatalysts capable of adsorbing and decomposing the odour and tar components of tobacco smoke under irradiation with UV or visible light. The processes of odour component adsorption and subsequent decomposition under irradiation were evaluated in terms of colour changes in the catalytic system and by gas chromatography-mass spectrometry. By considering three different photocatalysts, namely TiO 2 , Fe(III)-grafted TiO 2 , and Cu(II)-grafted WO 3 , we assessed the magnitude of odour and tar component adsorption on the fabric fibres, as well as the decomposition of these species after specific visible light or UV irradiation periods. Considering the expansion of our technology for practical applications, the best results among the three tested materials were obtained for non-woven fabric-supported Fe/TiO 2. We believe that our technology can be implemented in the design of interior decoration materials for creating a comfortable environment.

2024, Journal of Applied Electrochemistry

The capabilities of TiO 2-coated materials for the inactivation and removal of algae were investigated. As supports for TiO 2 , non-woven fabric and Ni foam were chosen. To evaluate the ability of noble metal cocatalyst additions to facilitate the photocatalytic algal inhibition of TiO 2-coated materials, Pd nanoparticles were deposited on non-woven fabric-supported TiO 2 by photoelectrochemical deposition. The fabric-supported Pd/TiO 2 showed higher inhibition activity for algal growth compared to the fabricsupported TiO 2 without Pd. In addition, Ni foam-supported TiO 2 also showed high inhibition activity, both in laboratory-scale tests and open-air tests. Therefore, TiO 2-coated materials with suitable coating methods such as the use of cocatalysts or large surface area can substantially inhibit algal growth. The ability of the TiO 2-coated materials to inhibit algae correlated well with their activity for the photocatalytic decolorization of methylene blue, suggesting a nonspecific mechanism in the breakdown of cellular structures.

2024

The General Chemistry 1 (SCC 201) course has been designated for the core competency of Inquiry and Problem Solving along with the Written Communication Ability. These abilities are best observed in the laboratory section of the course where SCC 201 students are asked to submit weekly written lab reports that range in chemistry topics from chemical structures to the chemical analysis of polluted environments. SCC 201 will be implementing a new experiment in the laboratory portion of the course entitled, "Thermochemistry: Heat of Neutralization and Hess's Law." The design of the experiment incorporates many elements of LaGCC's Core Competencies and Communication Abilities, as well as programmatic and course learning objectives both on the departmental and college levels. Natural Sciences major STEM students who successfully complete the thermochemistry lab and write a corresponding satisfactory lab report, will have engaged in two of the program goals, four of the student learning objectives and seven of the course objectives. The SCC 201 course lies in the midpoint Core Competency program curriculum map for both the Biology and Environmental Science programs and accounts for 3.5% of the final SCC 201 grade. Students will spend 3 hours completing the experiment in lab and in addition spend an estimated 3-4 hours completing the lab write-up. This lab was developed in the Natural Sciences programmatic integration CTL mini-grant seminar. The creation of the lab involved an initial discussion with members of the chemistry programmatic team to outline a common theme between SCC 201, SCC 202 and SCC 251. It was agreed upon that the central topic of thermodynamics would be implemented throughout the designated labs.

2024, International Journal of Electrochemical Science

Nanoporous nickel (np-Ni) was fabricated through dealloying of Ni-Al alloys and its application in lithium-ion batteries (LIBs) was assessed. The effect of alloy composition of the Ni-Al alloys on the formation of np-Ni has been investigated using X-ray diffraction (XRD), scanning electron microscopy combined with energy dispersive X-ray spectrometry (SEM-EDX), and 3D profilometry analysis. The experimental results show that the Ni-Al alloy composition has a significant effect on the dealloying feasibility, the phase constituents and the microstructures of the resultant np-Ni. As compared to Ni 50 Al 50 alloy, Ni 30 Al 70 was easier for dealloying since the percentage of Ni content is higher in Ni 50 Al 50. SEM images revealed that the np-Ni exhibited approximately a mean inner diameter of 71.10 ± 43.69 nm and 40.84 ± 24.70 nm for the Ni 30 Al 70 and Ni 50 Al 50 alloy, respectively. Pore distribution analysis revealed that due to the multiple intermetallic phases in the precursor Ni-Al alloys, the nanoporous structure was heterogeneous with a large variation in pore size and porosity. 3D profilometry revealed that almost all of the surfaces of the as-formed np-Ni displayed a leptokurtoic distribution. In addition, the surface area, pore volume, and mean pore diameter of the np-Ni were assessed using Brunauer-Emmett-Teller (BET) analysis. The specific surface area of the np-Ni dealloyed from Ni 30 Al 70 alloy was as high as 198.70 m 2 g-1 compared to 9.46 m 2 g-1 for dealloyed from Ni 50 A l50 alloy. The as-dealloyed np-Ni was used as negative electrode of LIBs and the performance was evaluated. The dealloyed np-Ni from Ni 30 Al 70 alloy with an oxide (NiO) layer surface and highly conductive Ni metal cores exhibited maximum discharge capacity of 651 mA h g-1 at 1C rate after 9 th cycle, which is reduced to a neglectable level of 80 mA h g-1 after 150 th cycles.

2024, Fuel

Single pellets (%3 mm diameter) of high density polyethylene (HDPE) have been burned in an electrically heated bed of silica sand, fluidised by air or mixtures of N 2 and O 2 at atmospheric pressure. During the combustion of single pellets, measurements were made of the concentrations of CO and CO 2 in the offgas, enabling burnout-times to be derived. This was done for different temperatures (400-900°C) in a bubbling fluidised bed and a range of masses for the HDPE pellets. In addition, the size of the sand, the fluidising velocity and the concentration of O 2 in the fluidising gas were all varied. In a bed above 400°C, a polymer pellet melted on entering the hot sand, which was wetted to form a small aggregate (or ''blob'' 5mmindiameter)ofsandparticlesheldtogetherbymoltenpolymer.Next,theblobsankandvolatilisationandthermaldecompositionofthepolymerproducedhydrocarbonvapours,whichburnedmainlyabovethesand.Itwasdeducedthatthereareactuallythreerangesoftemperature,eachwithadifferentmechanismofcombustion.Withthebedinthehightemperatureregimeat640−900°C,burnoutwascontrolledbymasstransferofhydrocarbonvapour(deducedtohaveameancompositionofapproximately(C2H4)5)awayfromsuchablobofsandandmoltenpolymer.Whenthebedwasbetween485and640°C(themediumtemperatureregime),radiativeheattransfertoablobofpolymercontrolledburnout.At400−485°C(thelowtemperatureregion)theburnout−timewascontrolledbythevolatilisation(gasification)ofapolymerpellettoproduceacombustiblehydrocarbonvapour.Theactivationenergyforthisgasificationwas5 mm in diameter) of sand particles held together by molten polymer. Next, the blob sank and volatilisation and thermal decomposition of the polymer produced hydrocarbon vapours, which burned mainly above the sand. It was deduced that there are actually three ranges of temperature, each with a different mechanism of combustion. With the bed in the high temperature regime at 640-900°C, burnout was controlled by mass transfer of hydrocarbon vapour (deduced to have a mean composition of approximately (C 2 H 4) 5) away from such a blob of sand and molten polymer. When the bed was between 485 and 640°C (the medium temperature regime), radiative heat transfer to a blob of polymer controlled burnout. At 400-485°C (the low temperature region) the burnout-time was controlled by the volatilisation (gasification) of a polymer pellet to produce a combustible hydrocarbon vapour. The activation energy for this gasification was 5mmindiameter)ofsandparticlesheldtogetherbymoltenpolymer.Next,theblobsankandvolatilisationandthermaldecompositionofthepolymerproducedhydrocarbonvapours,whichburnedmainlyabovethesand.Itwasdeducedthatthereareactuallythreerangesoftemperature,eachwithadifferentmechanismofcombustion.Withthebedinthehightemperatureregimeat640−900°C,burnoutwascontrolledbymasstransferofhydrocarbonvapour(deducedtohaveameancompositionofapproximately(C2H4)5)awayfromsuchablobofsandandmoltenpolymer.Whenthebedwasbetween485and640°C(themediumtemperatureregime),radiativeheattransfertoablobofpolymercontrolledburnout.At400−485°C(thelowtemperatureregion)theburnout−timewascontrolledbythevolatilisation(gasification)ofapolymerpellettoproduceacombustiblehydrocarbonvapour.Theactivationenergyforthisgasificationwas58 kJ/mol. This is the same as that characterising the ignition delay, which was also measured. The measured rates of burning indicate an enthalpy of gasification of %450 J/g. The total yield of CO and CO 2 was found to depend on the bed's temperature and was low enough to indicate that soot, together with unburned hydrocarbons, can be important products from such a bed.

2024, Physical chemistry chemical physics : PCCP

2024, Sensors

Efficient direct electron transfer (DET) between a cellobiose dehydrogenase mutant from Corynascus thermophilus (CtCDH C291Y) and a novel glassy carbon (GC)-modified electrode, obtained by direct electrodeposition of gold nanoparticles (AuNPs) was realized. The electrode was further modified with a mixed self-assembled monolayer of 4-aminothiophenol (4-APh) and 4-mercaptobenzoic acid (4-MBA), by using glutaraldehyde (GA) as cross-linking agent. The CtCDH C291Y/GA/4-APh,4-MBA/AuNPs/GC platform showed an apparent heterogeneous electron transfer rate constant (k s) of 19.4 ± 0.6 s −1 , with an enhanced theoretical and real enzyme surface coverage (Γ theor and Γ real) of 5287 ± 152 pmol cm −2 and 27 ± 2 pmol cm −2 , respectively. The modified electrode was successively used as glucose biosensor exhibiting a detection limit of 6.2 µM, an extended linear range from 0.02 to 30 mM, a sensitivity of 3.1 ± 0.1 µA mM −1 cm −2 (R 2 = 0.995), excellent stability and good selectivity. These performances compared favourably with other glucose biosensors reported in the literature. Finally, the biosensor was tested to quantify the glucose content in human saliva samples with successful results in terms of both recovery and correlation with glucose blood levels, allowing further considerations on the development of non-invasive glucose monitoring devices.

2024, Angewandte Chemie International Edition

A biohybrid photobioanode mimicking the Z‐scheme has been developed by functional integration of photosystem II (PSII) and PbS quantum dots (QDs) within an inverse opal TiO2 architecture giving rise to a rather negative water oxidation potential of about −0.55 V vs. Ag/AgCl, 1 m KCl at neutral pH. The electrical linkage between both light‐sensitive entities has been established through an Os‐complex‐modified redox polymer (POs), which allows the formation of a multi‐step electron‐transfer chain under illumination starting with the photo‐activated water oxidation at PSII followed by an electron transfer from PSII through POs to the photo‐excited QDs and finally to the TiO2 electrode. The photobioanode was coupled to a novel, transparent, inverse‐opal ATO cathode modified with an O2‐reducing bilirubin oxidase for the construction of a H2O/O2 photobioelectrochemical cell reaching a high open‐circuit voltage of about 1 V under illumination.

2024, Chemical Engineering Science

A Riser Simulator was employed to study OCM. An automatic injection was designed to inject reactants and to sample products. SmzO 3 catalyst was developed to suit the staged oxygen injection concept. Systematic runs were carried out between 500 and 700°C. A three lump reaction model, including C 2 and CO~ lumps, was considered. Simulated C2 selectivities showed 25% for co-feeding (one injection) and 58~ for staged oxygen (several injections).

2024, Chimia

handling manufacturing processes in microstructured continuous systems offers a variety of benefits to chemical as well as process performance. in this report, representative examples are given for profits in general process development, high exothermic/hazardous reactions, handling of products that are unstable under reaction conditions and product profile improvement. specific focus was aimed at reasonable timeframes for 0.5-1 kg campaigns by using commercially available microreaction technology. After analyzing the individual contributions of flow technology, we assembled a competitive minimal microreaction system comprising all essential parts for running effective continuous chemistry.

2024, CHIMIA

Handling manufacturing processes in microstructured continuous systems offers a variety of benefits to chemical as well as process performance. In this report, representative examples are given for profits in general process development, high exothermic/hazardous reactions, handling of products that are unstable under reaction conditions and product profile improvement. Specific focus was aimed at reasonable timeframes for 0.5–1 kg campaigns by using commercially available microreaction technology. After analyzing the individual contributions of flow technology, we assembled a competitive minimal microreaction system comprising all essential parts for running effective continuous chemistry.

2024, Applied Surface Science

Despite their chemical inertness and poor hydrophobicity, carbon-based materials are widely used in electrochemical applications due to their robustness, good electrical conductivity and corrosion resistance. The purpose of the work carried was to increase the wettability of nonwoven carbon fiber felts for improved efficiency in bio/electrochemical applications. Virgin Carbon Felt (VCF) was first treated with cold remote plasma (CRP) using a mixture of nitrogen and oxygen (1 or 2 %) as plasma gas. Bio-functionalization of the carbon felts with glucose oxidase (GOx) enzyme was then carried using physical adsorption method. FTIR and XPS analysis showed an integration of new oxygenated functional groups (C-O and C=O) as well as amines and amides on the surface of VCF treated by the CRP treatment, which improved the wettability of the samples. Capillary uptake increased from around 0 % (for VCF) to nearly 750 % with 2 % oxygen in plasma gas. GOx enzyme showed higher activity after immobilization at pH 5.5 on the CRP treated samples, maintaining up to 50 % of its initial enzymatic activity after six cycles while with the VCF, no enzymatic activity was observed after the fourth cycle. These obtained felts can be used as electrodes in sustainable bioprocesses.