The photoelectrochemical cell with hydrogen accumulation at the conditions of natural insolation (original) (raw)
Related papers
2016
The photo-electrochemical processes on epitaxial films of n-GaAs and polycrystalline films CdSe after modifying their surface by nano-sized particles of CdS, Zn, Pt, graphene oxide and Nb 2 O 5 have been studied. It revealed that the modification of the electrode causes increase in their photosensitivity, which comes from reduced rates of surface recombination and photocathode reactions that take place with the participation of surface electronic states. As cathodes for the hydrogen production there were used the nano-composites based on multiwalled carbon nanotubes and reduced graphene oxide. Materials analyzed are rather promising to be used as electrodes for electrochemical cells in solar hydrogen production.
Photoelectrochemical properties of the composites based on TiO2 nanotubes, CdSe and graphene oxide
Research on Chemical Intermediates, 2019
The photoelectrochemical properties of electrodes based on a nanocomposite consisting of TiO 2 nanotubes and CdSe films modified with graphene oxide have been studied. It is shown that in such a nanocomposite, a good adhesion of the CdSe layer to the substrate is provided. In this nanocomposite, the cathodic dark leakage currents are lower, and the efficiency of photoelectrodes is higher. From studies of Raman spectra, in which 2LO and 3LO phonon lines were observed, the quality of the modified polycrystalline films of CdSe was concluded. The amount of graphene oxide in NT-TiO 2 /CdSe/GO composite was determined to be 1.16 mass%, which allows one to obtain optimal photosensitivity of electrodes. It was established that the introduction of graphene oxide into semiconductor electrodes leads to an increase in their photosensitivity which is associated with a decrease of the surface recombination rate. The efficiency of the investigated nanocomposites in the photoelectrochemical cell for hydrogen production was studied together with composites based on graphene materials.
Solar energy conversion using CdSe photoelectrochemical cells with low cost substrates
Solar Cells, 1980
Photoelectrochemical cells using electrocodeposited CdSe films on low cost substrates (stainless steel and graphite) were studied. The usefulness of graphite as a counterelectrode in place of platinum was demonstrated. Results are reported for three cell configurations: stainless steel lCdSell electrolyte II Pt; stainless steel I CdSe [I electrolyte li C; C [CdSe [[ electrolyte II Pt.
In this paper it was made a comparative study of the doped TiO2 thin films used as photoelectrodes by using a versatile photoelectrochemical cell. The experimental arrangement makes possible the relative evaluation of the electrodes properties by measurement of the electric parameters, giving directly I = f(U) for the cell electric circuit by using an "internal" chemical bias. It is also possible to measure the volume of the evolved gas, and to analyze it by a gas-chromatograph and by a mass spectrometer.
Journal of Physics Conference Series 09/2009; 182(1):012080. DOI:DOI:10.1088/1742-6596/182/1/012080 , 2009
Abstract. It was built a versatile photoelectrochemical cell devoted to the comparative study of the photosensitive materials used as photoelectrodes in solar-hydrogen production. The experimental arrangement make possible a relative evaluation of the electrodes properties by the measurement of the electric parameters, giving directly I = f (U) for the cell electric circuit with and without an external electrical bias. It also gives a direct measurement of the volume of the evolved gases, and an on-line analyze of the gases by the coupled gas chromatograph, or of-line, by a mass spectrometer.
In this study, CdS, TiO2, CdSe, WO3, Fe2O3, and CuO/Cu2O based photoelectrode coating materials are considered for investigation under some significant selected coating methods, namely, chemical vapor deposition (CVD), electrochemical deposition (ECD), electrodeposition (ED), solegel (SG), spin coating (SC), and spray pyrolysis (SP). Their performance evaluations are carried out comparatively for photoelectrochemical hydrogen production. The photocurrent generation and voltage/light requirements of these photoelectrodes are also compared to evaluate the impact of material and method selection on photoelectrochemical hydrogen generation. The results show that among selected photoelectrode coating materials, CdS based photoelectrodes generate the highest photocurrent (3715.58 mA/cm2), followed by CdSe (2963.43 mA/cm2), CuO/Cu2O (1873.33 mA/cm2), TiO2 (1500.60 mA/cm2), WO3 (1435.28 mA/cm2), and Fe2O3 (443.3 mA/cm2). Average photocurrent densities of selected coating methods show that photocathodes processed by spin coating produce the highest photocurrent (2343.57 mA/cm2), followed by electrochemical deposition (1623.36 mA/cm2), electrodeposition (1359.77 mA/cm2), spray pyrolysis (1217.50 mA/cm2), chemical vapor deposition (619.44 mA/cm2), and sol-gel (335.06 mA/cm2).
Stabilizing effect in nano-titania functionalized CdS photoanode for sustained hydrogen generation
Efficient and stable photoanode has been fabricated by the surface functionalization of the nanostructured film. For this, the surface of spray deposited CdS thin film was modified through bi-functional molecule mediated chemisorption of TiO2 nanoparticles (NP). Consequently, a systematic control over efficiency and photoanode stability against corrosion has been investigated. An in-depth quantitative analysis of the photocorrosion of these photoanodes is further studied using chronoamperometry, X-ray photoelectron spectroscopy and induced coupled plasma spectroscopy. TiO2 NP modified photoanodes show an enhanced efficiency and a stability. For photoelectrochemical (PEC) systems, the stability factor (P) has been defined for the first time based on the time dependent chronoamperometry, which clearly demonstrates that Pmodified >> Pbare. The modified photoanode shows an improved Incident Photon to Current Efficiency of 22% than the bare CdS (w8%) electrode. It gives an enhanced solar-to-hydrogen conversion efficiency of STH w 0.7% w.r.t bare CdS (0.2%) under AM 1.5G solar simulator, at 0.2 V/SCE. Improved stability of more than nine hours and enhanced efficiency is attributed to the controlled passivation of CdS surface through TiO2 NP (5 nm), and inhibition of the charge recombination. Superior and stable performance of modified photoelectrode has been validated by higher and stable hydrogen evolution over modified electrode.
Journal of Applied Electrochemistry, 2019
A comparative study of hydrogen evolution in devices based on cadmium chalcogenides quantum dots (CdS, CdSe and CdTe) and its combinations, sensitizing TiO 2 was carried out. A maximum photocurrent of 2.7 mA cm −2 at 0 V bias, and a solar-to-hydrogen (STH) conversion efficiency of 0.9%, was obtained with CdSe QDs due to its wide absorption range. The co-sensitized device with CdS-CdSe QDs showed a higher photocurrent of 3.9 mA cm −2 with an STH of 1.2%. The improvement in hydrogen generation for electrodes sensitized with CdS in combination with CdSe or CdTe QDs, was attributed to the increased light absorption and appropriate band alignment for the enhanced charge transport.
Physical Chemistry Chemical Physics, 2014
We report on the fabrication of CdSe quantum dot (QD) sensitized electrodes by direct adsorption of colloidal QDs on mesoporous TiO 2 followed by 3-mercaptopropionic acid (MPA) ligand exchange. High efficiency photoelectrochemical hydrogen generation is demonstrated by means of these electrodes. The deposition of ZnS on TiO 2 /CdSe further improves the external quantum efficiency from 63% to 85% at 440 nm under À0.5 V vs. SCE. Using the same photoelectrodes, solar cells with the internal quantum efficiency approaching 100% are fabricated. The ZnS deposition increases the photocurrent and chemical stability of the electrodes. Investigation of the carrier dynamics of the solar cells shows that ZnS enhances the exciton separation rate in CdSe nanocrystals, which we ascribe to the formation of a type II heterojunction between ZnS and CdSe QDs. This finding is confirmed by the dynamics of the CdSe photoluminescence, which in the presence of ZnS becomes noticeably faster. † Electronic supplementary information (ESI) available: Electrochemical reaction in photoanodes and cathodes, the effects of MPA ligand exchange for QDSSCs, absorbance, transmittance and reflectance spectra, photoluminescence of samples with different sequences of CdSe and ZnS on TiO 2 , electrochemical impedance spectroscopy (EIS) measurements, equivalent circuit fitting results of EIS and other parameters of cells, and TRPL fitting results. See
Bulletin of Materials Science, 2007
Thin films of CdSe were deposited by potentiostatic mode on different substrates such as stainless steel, titanium and fluorine tin-oxide (FTO) coated glass using non-aqueous bath. The preparative parameters were optimized to get good quality CdSe thin films. These films were characterized by X-ray diffraction (XRD), optical absorption and photoelectrochemical (PEC) techniques. XRD study revealed that the films were polycrystalline in nature with hexagonal phase. Optical absorption study showed that CdSe films were of direct band gap type semiconductor with a band gap energy of 1⋅8 eV. PEC study revealed that CdSe film deposited on FTO coated glass exhibited maximum values of fill factor (FF) and efficiency (η) as compared to the films deposited on stainless steel and titanium substrate.