Calomel Electrode Research Articles

Low fouling electrochemical sensing in complex biological media by using the ionic liquid-doped conducting polymer PEDOT: application to voltammetric determination of dopamine.

An electrochemical sensor that can resist biofouling even when operated in complex biological medium is developed for the determination of dopamine. It is based on the use of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) that is doped with the water insoluble ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. A glassy carbon electrode modified with PEDOT/IL is shown to enable accurate determination of dopamine, as a model analyte in the presence of high concentrations of proteins, and resist biological fouling even in native serum. It exhibited a low limit of detection of 33nM for the detection of dopamine, with a wide linear range from 0.2 to 328μM (at 0.2V vs. saturated calomel electrode). The PEDOT/IL modified glassy carbon electrode has a porous microstructure, high electrical conductivity and good stability. The sensor can be used to quantify dopamine in human urine samples with satisfying accuracy. Graphical abstract An antifouling electrochemical sensor capable of detecting target in complex biological samples was developed based on the use of a conducting polymer (PEDOT) that wasdoped with awater insoluble ionic liquid.

Tribocorrosion performance of Zn, Zn[sbnd]Ni with magnesium electrodeposited on medium carbon steel in a chloride environment

The damage of materials due to both wear and corrosion has a significant impact on engineering systems. Therefore, the industry has recently been more focused on the life cycle costs of the systems and has sought to improve reliability. The reliability and efficiency of machines and equipment depend on tribocomponents operating in a chloride environment. Crucial components are subjected to a wide range of devastating tribocorrosion effects, and in many operations combined with mechanical loadings.A number of protection systems to mitigate corrosion in the marine environment have been employed to counter these problems. One of them are electrodeposited coatings such as Zn and ZnNi which were documented in numerous research. Much of it has been conducted in areas of corrosion behavior, mechanical properties, and tribology. In order to enhance the corrosion resistance of zinc film, various metals have been implemented. One of them is magnesium. The influence of Mg content in the alloy on the corrosion resistance has been noted by many researchers. However, one cannot find recent scientific publications and papers presenting tribocorrosion performance of Zn-Ni-Mg alloy coatings. Therefore, tribocorrosion behavior of ZnNi alloy coating with magnesium was investigated.The main aim of this study is to investigate tribocorrosion performance of Zn, and Zn-Ni-Mg alloys coatings with a possibility to replace Zn coating in engineering systems. All coatings were provided on AISI 1045 medium carbon steel with trivalent chrome passivation. The study was carried out in a ball-on-plate combination in 3.5% solution of NaCl. A triple electrode system with a precision four-channel ATLAS 9833 potentiostat was used for monitoring the electrochemical phenomena. The reference electrode was a calomel electrode, SCE. Polarization curves for all samples in 3.5% NaCl were utilized. The evaluation of the surface wear of all samples with coatings was done. The measure of the wear was the depth of the wear trace which was defined on the basis of profilometric measurements. The value of hardness of coatings was identified.

Hollow mesoporous nickel dendrites grown on porous nickel foam for electrochemical oxidation of urea

The macroporous nickel foam (NF) with attached hollow mesoporous nickel dendrites (NF@p-Ni) was prepared through electrochemical deposition of copper-nickel dendrites on the NF (NF@CuNi) followed by selective removal of the copper cores. The deposition process under high cathodic current density in an acidic solution favored the formation of hydrogen bubbles which acted as a template for the subsequent growth of macroporous dendritic copper-nickel film with 10 μm scale pores. The copper appeared to play an important part in the growth of dendritic shape and hollow porous structure on the porous and conductive NF framework. In the electrochemical oxidation of urea, the NF@p-Ni electrode could offer abundant electroactive sites and porous channels for increasing the oxidation current density and efficiency compared to the NF@CuNi electrode. The NF@p-Ni electrode featuring macroporous catalyst layer of hollow dendrites on highly conductive NF framework expedited the charge-transfer reaction of urea electrooxidation and the evolution of gaseous products. Thus, the current density and efficiency of NF@p-Ni could reach 141 mA cm−2 and 82%, respectively, higher than those of NF@CuNi (110 mA cm−2 and 72%, respectively) in catalyzing the electrochemical oxidation of urea molecules at 0.60 V versus saturated calomel electrode.

Aqueous alkaline–acid hybrid electrolyte for zinc-bromine battery with 3V voltage window

Considerable efforts have been devoted to the development of zinc (Zn) batteries with new battery chemistries (eg. Zn-ion battery, Zn-halogen battery, Zn-alkaline battery, Zn-air battery) that are alternatives to Li-ion technology. Unfortunately, the progress of Zn batteries is hindered by their limited operating voltages (<1.8 V). To enhance the operating voltage, in this study, a new aqueous zinc-bromine (Zn-Br2) battery is demonstrated using alkaline–acid hybrid electrolytes. The alkaline–acid hybrid electrolytes provide a wide potential window from −1.6 to 1.4 V vs. saturated calomel electrode (SCE). The fabricated Zn-Br2 battery delivers an average operating voltage of 2.1 V, which is the highest reported value among all Zn batteries, including Zn-ion battery, Zn-halogen battery, Zn-alkaline battery and, Zn-air battery etc. Significantly, the as-developed aqueous Zn–Br2 battery also exhibited a long-term lifespan (2000 cycles) and ultrahigh specific capacity by combining battery-like and capacitive charge storage. This demonstration of a high-voltage aqueous Zn-Br2 battery configuration represents a significant new development of this class of aqueous electrochemical energy storage device.

Determination of Riboflavin at Carbon Nanotube Paste Electrodes Modified with an Anionic Surfactant

AbstractA Sodium lauryl sulfate modified carbon nanotube paste electrode (SLSMCNTPE) was fabricated for the electroanalysis of Riboflavin (RF) in phosphate buffer solution (PBS) at pH, 7.0 by cyclic voltammetry (CV). The electrode was found to be a very sensitive tool for detection of RF; it was shown that SLSMCNTPE yields a high current response towards RF as compared to the bare carbon nanotube paste electrode (BCNTPE). Key parameters were optimized for RF determination. The effects of surfactant concentration, pH, scan rate and concentration of RF on the oxidation peak current values were determined. The RF oxidation peak appeared at −440 mV and reduction peak at −575 mV vs. saturated calomel electrode (SCE). The SLSMCNTPE revealed good repeatability, reproducibility, stability, high electrochemical sensitivity in its voltammetric response and a detection limit of 9.25×10‐8 M.

Reclaimed Carbon Fiber-Based 2.4 V Aqueous Symmetric Supercapacitors

Carbon fiber (CF) is a promising material as carbon-based electrode and support for flexible supercapacitors. However, it still suffers from narrow voltage in the aqueous electrolyte due to the water decomposition (1.23 V). Herein, an aerobic pyrolysis is developed to recover aligned carbon fibers from carbon fiber reinforced polymers. More importantly, during this oxygen existence condition, the surface of reclaimed carbon fibers (RCFs) is etched into groove-shaped structure and modified by introducing abundant oxygen-containing functional groups, which significantly expands the negative potential window of RCFs-based electrode to −1.4 V (vs standard calomel electrode) and the working voltage of RCFs-based symmetric supercapacitor to 2.4 V in an aqueous electrolyte of 1.0 M Na2SO4, with capacitance retention of 90% and 93.6% after 10 000 cycles, respectively. This work well matches the aerobic pyrolysis of recovery of CFs from CFRPs and electrochemical performances of RCFs, supplying a new strategy to de...

Microwave-assisted hydrothermal synthesis and electrochemical characterization of niobium pentoxide/carbon nanotubes composites

Abstract

Preparation of Co3O4@ZnO core-shell nanocomposites with intrinsic p-n junction as high-performance photoelectrodes for photoelectrochemical cathodic protection under visible light

In this work, Co3O4@ZnO nanocomposite photoelectrodes with a core-shell structure were prepared, enabling enhanced photoelectrochemical activity under visible light illumination. This was demonstrated by the photoinduced cathodic polarization of 304 stainless steel in 3.5 wt% NaCl solution. The morphology, composition, crystalline structure and optical absorption properties of the photoelectrodes were characterized by various analysis techniques and UV–vis diffuse reflectance absorption spectroscopy. Results show that, compared to the ZnO nanorods, the Co3O4@ZnO nanocomposite photoelectrodes have a red shift of optical absorption and enhanced photoelectrochemical cathodic polarization on stainless steel under visible light. The enhanced photoelectrochemical performance is attributed to the narrow band gap of Co3O4 and the p-n junction formed at the Co3O4/ZnO interface. The Co3O4@ZnO nanocomposite photoelectrodes fabricated in this work achieve a photocurrent density of 10.5 μA/cm2 and a cathodic polarization potential of −720 mV (saturated calomel electrode) for 304 stainless steel in 3.5 wt% NaCl solution under visible light.

Promoter Effects of Functional Groups of Hydroxide-Conductive Membranes on Advanced CO2 Electroreduction to Formate.

The electrochemical reduction of CO2 at ambient conditions provides a latent solution of turning waste greenhouse gases into commodity chemicals or fuels; however, a satisfactory ion-conducting membrane for maximizing the performance of a CO2 electrolyzer has not been developed. Here, we report the synthesis of a sequence of hydroxide-conductive polymer membranes, which are based on polymer composites of poly(vinyl alcohol)/Guar hydroxypropyltrimonium chloride, for use in CO2 electrolysis. The effect of different membrane functional groups, including thiophene, hydroxybenzyl, and dimethyloctanal, on the efficiency and selectivity of CO2 electroreduction to formate is thoroughly evaluated. The membrane incorporating thiophene groups exhibits the highest Faradaic efficiency of 71.5% at an applied potential of -1.64 V versus saturated calomel electrode (SCE) for formate. In comparison, membranes containing hydroxybenzyl and dimethyloctanal groups produced lower efficiencies of 67.6 and 68.6%, respectively, whereas the commercial Nafion 212 membrane was only 57.6% efficient. The improved efficiency and selectivity of membranes containing thiophene groups are attributed to a significantly increased hydroxide conductivity (0.105 S cm-1), excellent physicochemical properties, and the simultaneous attenuation of formate product crossover.

Understanding the electrode reaction process of dechlorination of 2,4-dichlorophenol over Ni/Fe nanoparticles: Effect of pH and 2,4-dichlorophenol concentration

Herein, with the exploitation of iron and nickel electrodes, the 2,4-dichlorophenol (2,4-DCP) dechlorinating processes at the anode and cathode, respectively, were separately studied via various electrochemical techniques (e.g., Tafel polarization, linear polarization, electrochemical impedance spectroscopy). With this in mind, Ni/Fe nanoparticles were prepared by chemical solution deposition, and utilized to test the dechlorination activities of 2,4-DCP over a bimetallic system. For the iron anode, the results showed that higher 2,4-DCP concentration and solution acidity aggravated the corrosion within the electrode. The charge transfer resistance (Rct) values of the iron electrode were 703, 473, 444, and 437 Ω∙cm2 for the initial 2,4-DCP concentrations of 0, 20, 50, and 80 mg/L, respectively. When the bulk pH of the 2,4-DCP solution varied from 3.0, 5.0 to 7.0, the corresponding Rct values were 315, 376, and 444 Ω∙cm2, respectively. For the nickel cathode, the reduction current densities on the electrode at −0.75 V (vs. saturated calomel electrode) were 80, 106, and 111 μA/cm2, for initial 2,4-DCP concentrations of 40, 80, and 125 mg/L. The dechlorination experiments demonstrated that when the initial pH of the solution was 7.0, 5.0, and 3.0, the dechlorination percentage of 2,4-DCP by Ni/Fe nanoparticles was 62%, 69%, and 74%, respectively, which was in line with the electrochemical experiments. 10 wt.% Ni loading into Ni/Fe bimetal was affordable and gave a good dechlorination efficiency of 2,4-DCP, and fortunately the Ni/Fe nanoparticles remained comparatively stable in the dechlorination processes at pH 3.0.

Optimization of Fe content in Electrodeposited FeCoCu/Cu magnetic multilayer

The structural, magnetic and magnetoresistance properties of FeCoCu/Cu multilayers prepared by electrochemical deposition from a single bath containing 0.025, 0.05 and 0.1 M Fe under potentiostatic control are investigated. The deposition potentials were selected −1.5 V for magnetic layers and −0.4 V for non-magnetic layers concerning saturated calomel electrode. The multilayers exhibited face-centered-cubic structure in the X-ray diffraction. In the multilayer produced from the electrolyte containing 0.05 M Fe, the high saturation magnetization value (572.3 kA/m) was observed and it value drastically decreased 140.6 kA/m in the electrolyte containing 0.1 M Fe. The magnetoresistance measurements were carried out in magnetic fields in the range of ±955 kA/m. The high giant magnetoresistance value (18.7%) were obtained in the multilayer with 0.05 M Fe. In the magnetic sublayers of the multilayers, the more than Cu atoms deposited and due to this, the magnetoresistance curves exhibited the 2.5, 4.7, 2.4% anisotropic magnetoresistance contributions between longitudinal and transverse magnetoresistance.

Polyaniline assisted USB based sensor for determination of benzene biomarker

Benzene is a known Hemotoxic carcinogen for humans. The carcinogenic properties justify that any exposure to Benzene in ambient air needs to be monitored. Exposure to Benzene is indicated by presence of trans-trans Muconic Acid (ttMA) in urine of human as a biomarker. Currently the levels of biomarker are measured by sophisticated and costly equipment like High Precision Liquid Chromatography (HPLC). This commercial procedure is time consuming due to rigorous sample preparation, involvement of expensive equipment and need of expertise for analysis. To remedy this, USB assisted and Polyaniline (PANI) based point of care electrochemical sensor for detection of biomarker of Benzene is developed. To operate this system, one does not require sample preparation and trained hands.The system is USB based portable potentiostat which performs Linear Sweep Voltammetry (LSV) for detection of ttMA. The design comprises of potentiostat interfaced with microcontroller FRDM-KL 25Z of NXP semiconductors. The system detects nanoampere current with linear sweep voltage resolution of 800 μV. Graphical User Interface (GUI) facilitates to set the parameters like start potential, end potential, step size and scan rate of linear sweep voltage. The real time serial plotter equips the viewing and capture of real-time sensor data from electrochemical cell. The three-electrode electrochemical cell consists of PANI coated Aluminum as working, Graphite Pencil Electrode (GPE) as counter, and Saturated Calomel Electrode (SCE) as reference which is utilized for electrochemical detection of ttMA in urine sample.This system is capable of detecting ttMA in Urine which corresponds to intermediate (1-5 ppm) and high (>5 ppm) level exposure of Benzene in ambient air.

High-performance 2.5 V flexible aqueous asymmetric supercapacitors based on K+/Na+-inserted MnO2 nanosheets

The voltage of aqueous asymmetric supercapacitors is usually limited within 2 V, which hampers their practical application as energy storage device. Herein, three-dimensional porous alkaline ions-inserted δ-MnO2 nanosheet arrays are prepared via hydrothermal synthesis on a modified carbon cloth substrate with N-doped carbon nanowire network (N-CNN). Interestingly enough, the potential window of the MnO2 nanosheet arrays can be extended to 1.2 V versus saturated calomel electrode (vs. SCE). The charge storage mechanism of δ-MnO2 for serving as the cathode is discussed which reveals the behavior of insertion/extraction for alkaline ions in electrolyte solution. Carbon-coated Fe2O3 nanorod arrays supported on bare carbon cloth are also fabricated successfully, which can stably function as the anode in a broad negative potential window of −1.3-0 V (vs. SCE). Consequently, a flexible aqueous asymmetric supercapacitor with a high voltage of 2.5 V is constructed by using MnO2@N-CNN as the cathode and C@Fe2O3 as the anode. The MnO2@N-CNN//C@Fe2O3 device displays a large energy density up to 1.43 mWh/cm3 as well as excellent rate capability and cycling performance, which is among the best supercapacitors based on MnO2 materials. This work paves a novel way to develop high-voltage aqueous asymmetric energy storage devices with large capacitance and energy density.

Superlattice stacking by hybridizing layered double hydroxide nanosheets with layers of reduced graphene oxide for electrochemical simultaneous determination of dopamine, uric acid and ascorbic acid.

A self-assembled periodic superlattice material was obtained by integrating positively charged semiconductive sheets of a Zn-NiAl layered double hydroxide (LDH) and negatively charged layers of reduced graphene oxide (rGO). The material was used to modify a glassy carbon electrode which then is shown to be a viable sensor for the diagnostic parameters dopamine (DA), uric acid (UA) and ascorbic acid (AA). The modified GCE displays excellent electrocatalytic activity towards these biomolecules. This is assumed to be due to the synergistic effects of (a) excellent interfacial electrical conductivity that is imparted by direct neighboring of conductive rGO to semiconductive channels of LDHs, (b) the superb intercalation feature of LDHs, and (c) the enlarged surface with an enormous number of active sites. The biosensor revealed outstanding electrochemical performances in terms of selectivity, sensitivity, and wide linear ranges. Typically operated at working potentials of -0.10, +0.13 and + 0.27V vs. saturated calomel electrode, the lower detection limits for AA, DA and UA are 13.5nM, 0.1nM, and 0.9nM, respectively, at a signal-to-noise ratio of 3. The sensor was applied to real-time tracking of dopamine efflux from live human nerve cells. Graphical abstract Schematic of the preparation of a superlattice self-assembled material by integrating positively charged semiconductive sheets of Zn-NiAl layered double hydroxide (LDH) with negatively charged reduced graphene oxide (rGO) layers. It was applied to simultaneous electrochemical detection of dopamine (DA), uric acid and ascorbic acid.

Uso de extratos naturais como inibidores de corrosão para o aço AISI 304

O trabalho baseia-se em estudar o efeito de compostos não tóxicos ao meio ambiente e provenientes de recursos naturais renováveis, utilizando-os como inibidores de corrosão ambientalmente seguros para o aço AISI 304 em meio de HCl 0,1 mol/L. A avaliação da proteção à corrosão foi feita com a imersão de placas de aço em alíquotas dos extratos aquosos e etanólicos de erva mate e chá verde. O potencial de corrosão foi determinado utilizando eletrodo de calomelano saturado como referência. Na ausência de inibidores em um tempo de 60 minutos, o ensaio controle, apresentou potencial de corrosão (Ecorr) igual a -158 mV/ECS. Já em presença de extrato aquoso de erva mate, o Ecorr foi de - 138 mV/ECS e -149 mV/ECS para o extrato aquoso de chá verde. Os extratos etanólicos de erva mate e chá verde apresentaram valores de potencial de corrosão de -58 mV/ECS e -143 mV/ECS, respectivamente. Apenas o extrato etanólico da erva mate apresentou resultado significativo na inibição do processo corrosivo no metal em estudo, apresentando médias de Ecorr antes e após tratamento inibidor estatisticamente diferentes pelo teste t pareado. Assim, o extrato etanólico de erva mate apresenta potencial uso como inibidor verde de corrosão.

CuII{(LISQ)˙-}2] (H2L: thioether-appended o-aminophenol ligand) monocation triggers change in donor site from N2O2 to N2O(2)S and valence-tautomerism.

Using a potentially tridentate o-aminophenol-based redox-active ligand H2L1 (2-[2-(benzylthio)phenylamino]-4,6-di-tert-butylphenol) in its deprotonated form, [Cu(L1)2] has been synthesized and crystallized as [CuII(L1)2]·CH2Cl2 (1·CH2Cl2). A cyclic voltammetry experiment (in CH2Cl2; V vs. SCE (saturated calomel electrode)) on 1·CH2Cl2 exhibits two oxidative (E = 0.20 V (peak-to-peak separation, ΔEp = 100 mV) and E = 0.90 V (ΔEp = 140 mV)) and two reductive (E = -0.52 V (ΔEp = 110 mV) and E = -0.92 V (ΔEp = 120 mV)) responses. Upon oxidation using a stoichiometric amount of [FeIII(η5-C5H5)2](PF6), 1·CH2Cl2 yielded [Cu(L1)2](PF6) (2). Structural analysis (100 K) reveals that 1·CH2Cl2 is a four-coordinate bis(iminosemiquinonato)copper(ii) complex (CuN2O2 coordination), and that the thioethers remain uncoordinated. The twisted geometry of 1 (distorted tetrahedral) results in considerable changes in the electronic structure, compared to well-known square-planar analogues. Crystallographic analysis of 2 both at 100 K and at 293 K reveals that it is effectively a four-coordinate complex with a CuN2OS coordination; however, a substantial interaction with the other phenolate O is observed. The metal-ligand bond distances and metric parameters associated with the o-aminophenolate rings indicate a valence-tautomeric (VT) equilibrium involving monocationic (iminosemiquinonato)(iminoquinone)copper(ii) and bis(iminoquinone)copper(i). Complex 1·CH2Cl2 is a three-spin system and a magnetic study (4-300 K) established that it has a S = 1/2 ground-state, owing to the strong antiferromagnetic coupling between the unpaired spin of the copper(ii) and the iminosemiquinonate(1-) π-radical anion. Electron paramagnetic resonance (EPR) spectral studies corroborate this result. Complex 2 is diamagnetic and the existence of VT in 2 was probed using variable-temperature (248-328 K) 1H NMR and EPR (100-298 K) spectral measurements and X-ray photoelectron spectroscopic studies at 298 K. Remarkably, modification of the well-studied 2-anilino-4,6-di-tert-butylphenol by incorporation of a benzylthioether arm leads to the occurrence of VT in 2. The electronic structure of 1·CH2Cl2 and 2 has been assigned using density functional theory (DFT) calculations at the B3LYP-D3 level of theory. Time-dependent (TD)-DFT calculations have been performed to elucidate the origin of the observed UV-VIS-NIR absorptions.

Polyethyleneimine/Graphene Multilayer Film Supported Ferric Cobalt Modified Electrode for High-Performance Sensing of L-cysteine

One novel chemically modified electrode (CME) was prepared through fabricating polyethyleneimine/oxidized graphene multilayers on indium tin oxide (ITO) slide via layer-by-layer assembly followed by electrochemically depositing cobalt hexacyanoferrate. A large range of methods were used to characterize the morphology and electrochemical properties of the electrode including field-emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, cyclic voltammetry, differential pulse voltammetry (DPV), electrochemical impedance spectroscopy and chronoamperometry. Under optimized conditions, the oxidation current of DPV (typically at 0.2 V vs. saturated calomel electrode) increased linearly in the range of 5 × 10−5 to 2 × 10−3 mol L−1. And the limit of detection and the limit of quantity were 4.6 × 10−7 mol L−1 and 1.5 × 10−6 mol L−1 (based on signal-to-noise ratio of 3 and 10), respectively. Average recoveries from (spiked) commercial mask were between 98.1% and 104.5% with relative standard derivations less than 3.14% (n = 3) at three spiked levels. The method was validated by HPLC. Furthermore, the possible mechanism of L-Cys detection was studied based on chronoamperometric experiments.

Amperometric sensing of hydrazine in environmental and biological samples by using CeO2-encapsulated gold nanoparticles on reduced graphene oxide.

CeO2-encapsulated gold nanoparticles (AuNPs) were anchored to reduced graphene oxide (RGO/Au@CeO2) by an interfacial auto-redox reaction in a solution containing tetrachloroauric acid and Ce(III) on a solid support. The resulting material was placed on a glassy carbon electrode (GCE) and used as an electrochemical hydrazine sensor at trace levels. The electrocatalytic activity of the modified GCE towards hydrazine oxidation was significantly enhanced as compared to only RGO/CeO2, or CeO2-encapsulated AuNPs, or AuNPsloaded on CeO2modified with RGO. This enhancement is attributed to the excellent conductivity and large surface area of RGO, and the strong interaction between the reversible Ce4+/Ce3+ and Auδ+/Au0 redox systems. The kinetics of the hydrazine oxidation was studied by electrochemical methods. The sensor, best operated at a peak voltage of 0.35V (vs. saturated calomel electrode), had a wide linear range (that extends from 10nM to 3mM), a low detection limit(3.0nM), good selectivity and good stability. It was successfully employed for the monitoring of hydrazine in spiked environmental water samples and to in-vitro tracking of hydrazine in cells with respect to its potential cytotoxicity. Graphical abstract CeO2-encapsulated gold nanoparticles anchored on reduced graphene oxide with the strong interaction between the reversible Ce4+/Ce3+ and Auδ+/Au0 reductions can be used for sensitive detection of hydrazine with detection limit of 3nM and good selectivity in environmental and biological samples.

Surface modification of TiO&lt;SUB align="right"&gt;2 nanorod arrays with Ag&lt;SUB align="right"&gt;3PO&lt;SUB align="right"&gt;4 @ PANI nanoparticles for enhancing photoelectrochemical performance

In this work, Ag3PO4@PANI particles with a core/shell structure were deposited onto the oriented TiO2 nanorod arrays (NRAs) by a facile dipping route, in order to enhance the visible-light response as well as photoelectrochemical (PEC) performance of TiO2 samples. Furthermore, the crystal structure, morphology, and optical properties of the composites (TiO2 photoanodes) were evaluated by a number of techniques, including scanning and transmission electron microscopy (SEM, TEM), X-ray diffractometry (XRD) and UV-vis spectroscopy. Meanwhile, on/off photocurrent response, and impedance spectroscopy measurements as well as Mott-Schottky analysis were employed to make a characterization over TiO2 photoanodes before and after surface modification. A photocurrent density of 4.0 mA cm−2 is achieved at 0.0 V vs. saturated calomel electrode (SCE) under an illumination of 100 mW/cm2, which is ~2 times higher than that of pristine TiO2 photoanode measured under the same conditions. The performance improvement was mainly attributed to the enhanced visible-light response of TiO2.

Surface modification of TiO&lt;SUB align="right"&gt;2 nanorod arrays with Ag&lt;SUB align="right"&gt;3PO&lt;SUB align="right"&gt;4 @ PANI nanoparticles for enhancing photoelectrochemical performance

In this work, Ag3PO4@PANI particles with a core/shell structure were deposited onto the oriented TiO2 nanorod arrays (NRAs) by a facile dipping route, in order to enhance the visible-light response as well as photoelectrochemical (PEC) performance of TiO2 samples. Furthermore, the crystal structure, morphology, and optical properties of the composites (TiO2 photoanodes) were evaluated by a number of techniques, including scanning and transmission electron microscopy (SEM, TEM), X-ray diffractometry (XRD) and UV-vis spectroscopy. Meanwhile, on/off photocurrent response, and impedance spectroscopy measurements as well as Mott-Schottky analysis were employed to make a characterization over TiO2 photoanodes before and after surface modification. A photocurrent density of 4.0 mA cm−2 is achieved at 0.0 V vs. saturated calomel electrode (SCE) under an illumination of 100 mW/cm2, which is ~2 times higher than that of pristine TiO2 photoanode measured under the same conditions. The performance improvement was mainly attributed to the enhanced visible-light response of TiO2.