Electrochemical detection of 4-nitrophenol based on biomass derived activated carbons (original) (raw)
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Journal of the Association of Arab Universities for Basic and Applied Sciences
The activated carbon doped by nickel oxide (NiO/AC) was prepared using solid reaction. The obtained powder was characterized using X-ray diffraction (XRD) and infrared spectroscopy (IR). The NiO/AC was also used to catalyze the electro-oxidation of phenol at carbon paste electrode (CPE) using electrochemical approaches. Kinetic parameters of phenol oxidation (as the electron transfer coefficient, diffusion coefficient and heterogeneous rate constant) were investigated. The results confirm that phenol oxidation is catalyzed by nickel oxide, due to resonance, steric and aggregation effects. The experimental conditions were optimized by varying chemical and electrochemical parameters, which involve the oxidation of phenol. The electrode NiO/AC-CPE exhibits a good linear range from 1.0 Â 10 À6 mol L À1 to 8.0 Â 10 À5 mol L À1 and 1.0 Â 10 À4 mol L À1 to 1.0 Â 10 À3 mol L À1 with a limit of detection of 7.09 Â 10-7 mol L-1 (signal (S) to noise (N) ratio, S/N = 3). This modified electrode NiO/AC-CPE offers a considerable improvement in voltammetric sensitivity toward phenol determination, compared to the unmodified electrode (CPE). The selectivity of the NiO/AC-CPE in detecting phenol was investigated for a number of ions (
New J. Chem., 2020
In this approach, low-dimensional silver oxide decorated carbon black nanocomposites (Ag 2 O/CB NCs) were synthesized by a facile wet-chemical process at low temperature. The prepared composites were characterized by Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV/vis), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and X-ray powder diffraction (XRD). A thin layer of Ag 2 O/CB NC was deposited on the glassy carbon electrode (GCE) with a conducting binder to produce the working electrode of a chemical sensor. The fabricated chemical sensor was used for the successive in vitro detection of 3-methoxyphenol (3-MP) by an electrochemical method at a lower applied potential. The sensor response towards 3-MP is linear in a logarithmic scale over a large concentration range (0.09 nM to 9.0 mM). The analytical parameters of the sensor, including good sensitivity (45.7278 mA mM À1 cm À2), low detection limit (LOD = 9.73 AE 0.49 pM at a signal to noise ratio of 3), good reliability, good reproducibility, and long-term stability were examined. Therefore, the proposed chemical sensor based on Ag 2 O/CB NCs/binder/GCE may be a promising sensitive chemical sensor in reliable electrochemical approaches for the broad-scale detection of hazardous and carcinogenic chemicals in the health care and environmental sectors.
Journal of Electrochemical Science and Engineering
In order to raise possible ways of MoO3 synthesis and improve its existing applications, MoO3 nanomaterial was successfully synthesized through the solvo-hydrothermal route by utilizing a mixture of ionic liquid (1-butyl-3-methylimidazolium bromide) as a solvent, and water as co-solvent in 1:1 ratio. The morphology and structural parameters of IL-assisted MoO3 product were examined by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Additionally, the surface wettability and particle size distribution were inspected using the contact angle and dynamic light scattering (DLS) analysis. Glassy carbon electrode (GCE) surface was then modified by IL-assisted MoO3. The formed IL-MoO3/GCE was employed as an electrochemical sensor for determination of 4-nitrophenol (4-NP), which is very toxic and important pollutant. The redox behavior of 4-NP at the surface of IL-MoO3/GCE was investigated by cyclic voltammetry (CV) and diffe...
Sensor Letters
An electrochemical sensor based on electrochemically reduced graphene oxide (ERGO) functionalized cetyltrimethylammonium bromide (CTAB) deposited on screen printed carbon electrode (SPCE) was developed for the detection of 3-nitrophenol. The ERGO/CTAB was prepared via drop casting technique on the screen printed carbon electrode (SPCE). The drop casted composite was then subjected to cyclic voltammetry technique to produce ERGO/CTAB. The modified electrode exhibits high electrocatalytic activity and good selectivity towards the reduction of 3-nitrophenol due to its excellent electrical conductivity, strong adsorptive ability and large effective surface area of ERGO functionalized CTAB. The enhancement factor of the ERGO/CTAB modified SPCE towards 3-nitrophenol was calculated to be 5.16 times higher compared to bare SPCE. Under optimum experimental conditions, the linearity of the sensor towards 3-nitrophenol concentration was in the range of 0.5 μM to 100 μM with the detection limit of 0.04 μM. Furthermore, the ERGO/CTAB sensor showed good reproducibility and also demonstrated efficiency in the detection of 3nitrophenol in water samples.
Journal of Molecular Liquids, 2019
P-Nitrophenol is a water pollutant with wide applications in petrochemistry, synthesis of dyes and pesticides. The material has however been reported to harmful effects on humans. Accordingly, the present work focused on developing a voltammetric sensor for the determination of p-nitrophenol using a modified carbon paste electrode (CPE) as the working electrode. The modification of the CPE was performed using NiO nanoparticles (NiONPs) and N-hexyl-3-methylimidazolium hexafluorophosphate (NH3MPF6). The resulting sensor showed very good performance in the analysis of p-nitrophenol in water samples. MAP, energydispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), atomic force microscopy (AFM), UV-vis and field emission scanning electron microscopy (FESEM) analyses confirmed the presence of high-purity NiONPs with a diameter size of 22.0 nm in the modified electrode. It was concluded that NiONPs and NH3MPF6 act as high-performance modifiers in the working electrode matrix and hence create a voltammetric sensor for nano-molar determination of pnitrophenol. Validation of the applicability of the sensors was performed through the determination of p-nitrophenol in different water samples, and the results indicated respective LDR and LOD values of ~0.01-280 μM and ~7.0 nM for p-nitrophenol.
Determination of 2-Nitrophenol by Electrochemical Synthesized Mg/Fe Layered Double Hydroxide Sensor
A novel, cheap and simple non-enzymatic amperometric sensor was fabricated based on electrodeposition of Mg/Fe layered double hydroxides (Mg/Fe-LDH) on glassy carbon (GC) electrode. The electrochemical synthesized Mg/Fe-LDH was characterized by the scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and cyclic voltammetry (CV) methods. The prepared Mg/Fe-LDH was found to have an excellent electrocatalytic activity toward the reduction of 2-Nitrophenol (2-NP). It has been shown that the Mg/Fe-LDH modified electrode, can be used as non-enzymatic amperometric sensor for determination of 2-NP in concentration range of 5-560M with limit of detection of 4M. The proposed method was used for determination of 2-nitrophenol in industrial waste waters. In addition, the modified electrode with Mg/Fe-LDH exhibited satisfactory reproducibility and a long-time stability.
2010
The electrochemical determination of o-nitrophenol by square wave voltammetry using a nanocomposite of generation 2 poly(propyleneimine) dendrimer and gold nanoparticles modified glassy carbon electrode is reported. A characteristic reduction peak at ca -650 mV for o-nitrophenol was observed with enhanced current. The nanocomposite electrode was used as a sensor for the detection of this model organic pollutant with very good reproducibility and stability. The reduction peak current was directly proportional to the o-nitrophenol concentration in the range between 6.1 x 10 -7 mol L −1 to 6.25 x 10 -4 mol L -1 . A detection limit of 4.5 x 10 -7 mol L −1 was calculated.
Novel Ni(II) Mixed Ligand Complex Modified Electrode: Catalytic Effect on Anodic Oxidation of Phenol
Electroanalysis, 2004
Cyclic voltammetry, using graphite paste electrode (GPE) and chemically modified GPE with Ni(II) mixed ligand complex (MGPE), is described for sensing and detoxification of phenol. A novel mixed ligand complex of nickel with 1,4,8,11-tetraaza cyclotetradecane (cyclam) and thiocyanate in the molar ratio of 1 : 2 : 5 is synthesized and characterized by spectroscopic and electrochemical studies. The Ni(II)-cyclam-thiocyanate complex behaves as a fast electron-transfer mediator, as nickel ions exist in higher oxidation state of Ni(III) on applying a potential of 1.25 V (vs. Ag/AgCl), which catalyses the oxidation of the target species. The mixed ligand complex, when incorporated in the graphite paste electrode, is sensitive to detect phenol as low as 10 mg/L in solution. The catalytic effect of the Ni(II)-cyclam-thiocyanate complex enhanced many folds the oxidation of phenol compared to GPE. The technique has potential for sensing/monitoring and detoxification of phenol released in the ecosystem from polluting industries.
2011
The electrochemical oxidation of p-nitrophenol (p-NP) has been studied comparatively on a graphene modified electrode and a multiwall carbon nanotube (MWNT) electrode by using cyclic and differential pulse voltammetry. The sensors were fabricated by modifying screen-printed electrodes with graphene and MWNT nanomaterials, respectively, both dispersed in Nafion polymer. p-NP is irreversibly oxidized at +0.9 V (vs. the Ag/AgCl) in solutions of pH 7. The height and potential of the peaks depend on pH in the range from 5 to 11. In acidic media, p-NP yields a well-defined oxidation peak at +0.96 V which gradually increases in height with the concentration of the analyte. In case of differential pulse voltammetry in sulfuric acid solution, the sensitivity is practically the same for both electrodes. The modified electrodes display an unusually wide linear response (from 10 μM to 0.62 mM of p-NP), with a detection limit of 0.6 μM in case of the graphene electrode, and of 1.3 μM in case of the MWNT electrode.
Recent advances in electrochemical modified Electrodes for sensing phenol derivatives
2018
Enzymless electrode is a device combines a material component and electrochemical transducer, used for the detection of an analyte. Nanomaterials are widely used in sen-sing areas due to its high positive effect on the response of enzymeless based electrode, itcould be used as transduction element or immobilized onto the surface of electrochemical transducers, their presence increases sensitivities and gives a lower detection limits andenhance the kinetic performance of sensors. In this work, we report the effect of the most recent nonmaterial used for electrochemical detection, catalytic effect of various nanopar- ticles such as, nanomaterials, gold nanoparticles, conducting polymer, carbon nanotubes, and metal oxide immobilized on the surface of electrochemical transducers (platinum electrode, Carbon electrode and Gold electrode) is intensively analyzed. A comparativestudy of the nanoparticles effect on the analytical performance of sensor for the detectionof phenolic compounds is...