Chronoamperometry Studies Research Articles

Effect of Tl+ Intercalation on Electrochromic Behavior of Tungsten Heteropolyoxometalate Polymeric Thin Films

SummaryTungsten oxide (WO3) and molybdenum oxide (MoO3) are an extensively studied EC materials due to its outstanding electrochromic properties. Hence in present investigation Tl+ intercalated tungsten heteropolyoxometalate polymeric thin films have been successfully deposited on the FTO‐coated glass substrates using low cost chemical bath deposition technique. The films formed were uniform and well adherent. For the electrochemical characterization, the standard three‐electrode electrochemical cell was used. The polymeric thin films show good EC properties. By observing various parameters obtained from cyclic voltammetry, chronoamperometry and iono‐optical studies of tungsten heteropolyoxometalate thin films it is clear that, reversibility of phosphotungstic acid (PTA) increases after intercalation of thallium but coloring efficiency (CE) decreases.

Synthesis and characterization of gold nanoparticles incorporated bentonite clay for electrocatalytic sensing of arsenic(III)

In the present manuscript, a simple and easy route to synthesize bentonite (bt) clay-supported gold nanoparticles (Au NPs) is reported (represented as Au-bt). Application of this new environmentally benign material in electrocatalytic determination of arsenite (As(III)) was studied. The successful synthesis and incorporation of Au NPs into the bt clay is supported by spectroscopic, microscopic and electrochemical methods. The synthesized Au-bt material was used to modify glassy carbon electrode (GC) by the evaporation of Au-bt aqueous suspension dropped on the surface of the GC (GC/Au-bt). Cyclic voltammetry and chronoamperometry studies of As(III) solutions were performed with this GC/Au-bt electrode which act as efficient platform for the electro-oxidation of As(III) to As(V) at a very low overpotential. Kinetic parameters were evaluated for the oxidation of As(III) at the GC/Au-bt platforms. A wide linear calibration range for the determination of As(III) from 1 to 1700 μM was obtained with high reproducibility and stability. A limit of detection, 0.1 μM was achieved with high sensitivity. Additionally, it showed a good selectivity for the determination of As(III) in the presence of copper(II) and other interfering ions suggesting a promising new route for trace level determination of As(III) in neutral conditions.

Patternable Rough Textured Gold Microwire for Neurochemical Sensing

ABSTRACTUnderstanding spatial and temporal neuronal activities is crucial for finding the cure for brain related ailments and advancement of our knowledge about the brain itself. This paper discusses our recent finding of the patternable rough textured gold microwire for neurochemical sensing. We have successfully fabricated the ∼5 µm wide and ∼ 60 nm thick gold microwires based electrochemical sensor. We produced these microwires along the edge of lithographically patterned nickel thin film. A nickel thin film edge was shadowed by the photoresist overhang during electrochemical growth only to allow gold deposition along the edges. Our electrochemical growth conditions yielded very rough textured sensor. Rough textured biosensors are highly desirable for increasing surface/volume ratio for efficient electrochemical sensing. These rough-textured microwires were transformed into the functional neurochemical sensor to detect dopamine. Our voltammetry and chronoamperometry studies on rough textured microwires based sensor confirmed the successful detection of dopamine.

Hydrogen Co-Deposition Induced Phase and Microstructure Evolution of Cobalt Nanowires Electrodeposited in Acidic Baths

The growth and deposition mechanism of electrodeposited cobalt nanowires (NWs) at different bath temperatures (25°C–60°C) in strongly acidic bath (pH of 2.0) is studied. CV scans show that hydrogen co-deposition is most pronounced in 50°C bath. X-ray diffraction patterns of Co NWs show that a mixture of hcp and fcc phases grows at 25°C, (200) textured fcc-Co phase grows at 50°C, and and (110) textured hcp-Co phase at 60°C, with these planes normal to the NW-axis. The magnetic properties studied by vibrating sample magnetometer show the change in coercivity, saturation field and magnetization reversal behavior is consistent with the phase of NW. Nucleation mechanism is explained on the basis of intermediates formation induced by the extent of hydrogen co-deposition leading to the change in nucleation overpotential and linked selection of the growth plane as per bath pH and temperature. Chronoamperometry study has confirmed the instantaneous and progressive growth mechanisms operative at 50°C and 60°C respectively and hydrogen co-deposition controlled grain size growth model is also put forth to understand the growth kinetics of fcc and hcp phase Co NWs. The suggested growth mechanism also consistently explains the growth in less acidic bath of pH 4.5.

High Surface Area Carbon Electrodes for Bromine Reactions in H2-Br2 Fuel Cells

In a hydrogen-bromine (H2-Br2) fuel cell, the Br2 reactions don't require precious metal catalysts, hence porous carbon gas diffusion media (GDM) are widely used as electrodes. However, the specific surface areas of the commercial carbon gas diffusion electrodes (GDEs) are quite low and need to be enhanced. In order to improve the active surface area of carbon GDEs, a study was conducted to grow multi-walled carbon nanotubes (MWCNTs) directly on the carbon electrode fiber surface. Both constant and pulse current electrodeposition techniques were used to deposit Co nanoparticles to catalyze the MWCNT growth. The MWCNTs were grown in the presence of a mixture of acetylene, argon, and hydrogen gases using the chemical vapor deposition process. Based on the results obtained from SEM, TEM, and EDX analysis, MWCNT growth following the tip model was confirmed. The results from the multi-step chronoamperometry study have shown that the synthesized carbon GDEs with MWCNTs have 7 to 50 times higher active surface area than that of a plain GDE. The performance of a single layer of the best MWCNT GDE measured in a H2-Br2 fuel cell was found to be equal or slightly higher compared to that obtained using a three-layer plain carbon electrode.

Electrochemical Formation and Phase Control of Mg–Cu Alloys

AbstractMg–Cu alloys with different phases were electrodeposited in a molten LiCl–KCl eutectic mixture containing a small amount (0.5 mol %) of MgCl2 at 673 K. The electrochemical behavior of the MgII ion and alloy formation processes were studied at inert molybdenum (Mo) and active copper (Cu) electrodes in the molten salts, respectively. Different electrochemical techniques, such as cyclic voltammetry, square‐wave voltammetry, chronoamperometry, and open‐circuit potentiometry were carried out to investigate the electrochemical formation mechanism of Mg–Cu alloys. Three signals, corresponding to the formation of metal Mg and two different Mg–Cu alloy phases, are observed when using cyclic voltammetry, square‐wave voltammetry, and open‐circuit potentiometry. Chronoamperometry studies indicate the different interfacial properties of the magnesium metal versus the Mg–Cu alloys. The results of X‐ray diffraction and scanning electron microscopy show that the MgCu2 and Mg2Cu phases could be obtained at −2.30 and −2.38 V (vs. Pt), respectively.

Using of anionic adsorption property of a surfactant modified clinoptilolite nano-particles in modification of carbon paste electrode as effective ingredient for determination of anionic ascorbic acid species in presence of cationic dopamine species

A novel carbon paste electrode containing modified clinoptilolite nano-particles with hexadecyltrimethylammonium surfactant (or surfactant modified zeolite (SMZ)) was constructed and used for selective voltammetric determination of ascorbic acid (AA) in the presence of dopamine (DA), because the SMZ present in the modified electrode adsorbs anionic AA species and repels cationic DA species. This caused to increase the over-voltage of electro-oxidation of DA by ∼600mV with respect to AA in square wave voltammetry (SqW). Hence, AA and DA can be effectively determined by the modified electrode in their aqueous mixture. Comprehensive CV, SqW and chronoamperometry (ChA) studies were done on AA using the proposed electrode. The widest linear responses with detection limits of 6.1×10−8moldm−3 and 5.9×10−12moldm−3 were respectively obtained for AA in SqW and ChA techniques. The diffusion coefficient of ascorbic acid was equal to 4.1×10−5cm2s−1. The proposed method was successfully applied for the determination of AA in different pharmaceutical and food samples which of their AA contents were obtained as: 497.4±1.2 mg per Chewable tablet, 246.9±1.4mg per Vitamin C tablet, 501.3±0.8mg per Vitamin C ampoule, 45.2±1.1mg per 100g of Sweet lemon, 50.6±0.7mg per 100g of Orange, 36.9±0.9 mg per 100g of Grapefruit, 31.2±1.3 mg per 50g of Sour lemon, 9.5±1.0 mg per 250mg of Lemonade.

Photovoltaic performance of curcumin as sensitizer in a solid-state solar cell

The sensitization of ZnO nanoparticles thin film with a natural substance curcumin and its use as photoanode in a solid-state dye-sensitized solar cell (SS-DSSC) employing TiO2 nanofiller modified polyethylene oxide (PEO) polymer electrolyte is reported. The diffuse reflectance spectrum (DRS) of the curcumin dye adsorbed ZnO thin film has exhibited a strong absorbance in the wavelength range of 380–520nm, indicating a good adsorption of curcumin dye molecules on the ZnO thin film surface. The photovoltaic performance of the SS-DSSC is evaluated under simulated solar light intensity of 600W/m2. The SS-DSSC with ZnO thin film electrode sensitized by curcumin has delivered a photocurrent density (Jsc) of 331×10−6Acm−2 and overall energy conversion efficiency (η) of 0.13%. The high charge transfer resistance exhibited by the solid-state PEO polymer electrolyte is responsible for the low Jscvalue of the cell. The stability of the SS-DSSC is proved through chronoamperometry study.

The electrooxidation of borohydride: A mechanistic study on palladium (Pd/C) applying RRDE, 11B-NMR and FTIR

Electrochemical borohydride oxidation reaction, intermediates and reaction products are studied by cyclic voltammetry with rotating disk electrodes, chronoamperometry coupled with 11B NMR spectroscopy and in-situ FTIR measurements. Depending on the electrode potential of a Pd/C catalyst on a rotating disk electrode the number of exchanged electrons varies between four and eight. By employing chronoamperometry the boron species are analyzed during the ongoing reaction with NMR. During all experiments no boron products other than BO2− are detected. Incomplete borohydride consumption during the chronoamperometry studies show that the palladium surface is poisoned by an intermediate in the low potential region. In-situ FTIR measurements confirmed that there is no interaction with BH2-species which are acting as catalyst poison.

Serotonin Transporter‐Independent Actions of the Antidepressant Vortioxetine as Revealed Using the SERT M172 Mouse

The most common antidepressants are serotonin (5‐HT) selective reuptake inhibitors (SSRIs), believed to provide benefit by antagonizing the 5‐HT transporter (SERT). To improve efficacy, drugs have been developed that target additional sites, which questions whether one (e.g. SERT) or more of the anticipated targets accounts for therapeutic efficacy. For example, the novel antidepressant vortioxetine (VORT) antagonizes SERT, but also interacts with 5‐HT1A, 3, and 7 receptors at clinically relevant doses. We assessed the SERT‐dependent actions of VORT using a novel transgenic mouse model (SERT Met172) that prior studies demonstrate limited high‐affinity interactions of many antidepressants, with normal 5‐HT transport function. Consistent with these findings, we documented a ~20x loss in potency for VORT at SERT in synaptosomal preparations compared to WT, consistent with evidence of reduced CNS SERT occupancy. Importantly, a loss of SERT interactions in the SERT M172 model could also be demonstrated in vivo following acute (10mg/kg i.p.) VORT injections, as monitored in chronoamperometry and microdialysis studies. Despite loss of VORT interactions with SERT in the M172 model, we found that, unlike citalopram and fluoxetine, VORT maintained its ability to reduce immobility in Tail Suspension and Forced Swim Tests. These findings indicate that the acute behavioral actions of VORT in these preclinical tests of antidepressant efficacy are independent of SERT antagonism, consistent with the potential for a novel mechanism of action in the treatment of depression

Co@Pt core–shell nanoparticles supported on carbon nanotubes as promising catalyst for methanol electro-oxidation

Co@Pt (Co-core, Pt-shell) 4–10nm sized particles supported on functionalized multi-walled carbon nanotubes (MWCNTs) have been synthesized and tested as efficient catalyst in direct methanol fuel cells (DMFCs). Catalytic activity and durability of all the catalysts for methanol oxidation (MO) have been studied in basic medium (0.5M KOH) using cyclic voltammetry (CV). Chronoamperometry studies revealed that Co@Pt/MWCNTs has significantly high efficiency and stability than both Pt/MWCNTs and Co@Pt/MWCNTs catalysts. Mass activity exhibited by Co@Pt/MWCNTs for MO is 1.61 and 3.36 times higher than those of Pt–Co/MWCNTs and Pt/MWCNTs, respectively.

Switching of the Rate-limiting Step in the Electrochromic Reduction of Fluorinated Phthalocyanine Thin Films by Decreased Intermolecular Coupling

Thin solid films (5-120nm) of the electron deficient perfluorinated phthalocyanine 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadeca-fluorophthalocyaninato copper(II) (F16PcCu) and the perfluoroalkyl-substituted perfluorophthalocyanine 1,4,8,11,15,18,22,25-octakis-fluoro-2,3,9,10,16,17,23,24-octakis-perfluoro(isopropyl) phthalocyaninato copper(II) (F64PcCu) have been prepared by physical vapor deposition onto a glass substrate coated with a transparent conductor (indium-tin-oxide, ITO). Cyclic voltammetry, chronoamperometry and spectroelectrochemical UV-vis spectroscopy studies revealed that the films were readily reduced and re-oxidized at potentials slightly negative of the Ag/AgCl reference electrode confirming a significant stabilization of the produced anions by the electron-withdrawing fluorinated substituents. A significant color change accompanied the change of the molecular redox states. Electroneutrality of the films was ensured by intercalation of K+-counter ions upon reduction and their ejection upon re-oxidation. Molecules of F64PcCu were reduced by one electron, those of F16PcCu by up to two, for thin films subjected to slow charging rates. In addition to a decisive influence on the electronic structure of the inner ring π-system of the metal complexes the steric hindrance of the fluorinated ligands influence the extent of intermolecular coupling. The perfluoroalkyl, Rf, groups in F64PcCu thereby led to widely decoupled electronic states of the molecules in the thin films as detected by the observed optical absorption spectra. The bulky Rf groups also led to facile diffusion of the K+-counter ions into the films, as well as to a significantly reduced electrical conductivity of F64PcCu relative to F16PcCu. Time-resolved measurements served to analyze the interplay of the two mandatory transport processes. Interestingly, the variability in steric hindrance results in a qualitative change in the rate-limiting steps of the reduction. Thus, in the case of F64PcCu the transport of electrons in the molecular films is rate-limiting, as opposed to counter ion diffusion in the case of F16PcCu. This switch underlines the importance of structural parameters for the tuning of the observed reduction and re-oxidation of organic thin films via intermolecular interactions.

Development of Graphene/CdSe Quantum Dots‐Co Phthalocyanine Nanocomposite for Oxygen Reduction Reaction

AbstractNanocomposites containing CdSe quantum dots, tetra(4‐(4,6‐diaminopyrimidin‐2‐ylthio) phthalocyaninatocobalt(II)) (CoPyPc) and reduced graphene nanosheets (rGNS) were devoloped and used for the modification of a glassy carbon electrode. Characterization of the nanocomposites was done by transmission electron microscopy (TEM) and X‐ray diffraction (XRD) analyses. Cyclic voltammetry (CV) was used for electrochemical characterization of the prepared nanocomposite for oxygen reduction reaction. The oxygen reduction activity for rGNS/CdSe‐CoPyPc nanocomposite was found to be superior over the individual nanomaterials in this study. The activity of the nanocomposite towards oxygen reduction was also tested for tolerance to methanol crossover effect using chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) studies.

Gold-Zinc-Cobalt Deposited on Titanium as Electrocatalysts for Borohydride Oxidation

Investigation of the electrochemical oxidation of borohydride in alkaline solutions on the ZnCo alloy deposited on the titanium surface and modified with gold nanoparticles (denoted as AuZnCo/Ti) is presented. The ZnCo alloy coatings with the thickness of ~5 µm were deposited on the titanium surface (1 x1 cm) via electrodeposition from the electrolyte described in Ref. [1]. Au crystallites were deposited on the ZnCo/Ti surface via the galvanic displacement technique. The ZnCo/Ti catalysts were immersed into the 1 mM HAuCl4 + 0.1 M HCl solution at 25 oC for 0.5, 1 and 5 min, respectively [2].The morphology, structure and composition of the prepared catalysts were examined by Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Analysis and Inductively Coupled Plasma Optical Emission Spectroscopy. Electrocatalytic activity of the prepared catalysts was investigated towards the oxidation of borohydride by means of cyclic voltammetry, chronoamperometry and chronopotentiometry.It has been determined that the AuZnCo/Ti catalysts with Au loadings of 31, 63 and 306 µg cm-2 show enhanced catalytic activity towards electro-oxidation of BH4 – ions as compared to that of ZnCo/Ti or Co/Ti catalysts. The chronoamperometry and chronopotentiometry studies also confirmed a high electrocatalytic activity of the AuZnCo/Ti catalysts for the direct electro-oxidation of BH4 – ions as compared to that of ZnCo/Ti and Co/Ti catalysts.

Amperometric Determination of L-Ascorbic Acid Using Copper Hexacyanoferrate Nanoparticles Modified Electrode

A new approach was attempted to prepare a chemically modified electrode using copper hexacyanoferrate (CuHCF) nanoparticles as the redox mediator and to study its stability and electrocatalytic activity for ascorbic acid (AA) oxidation. The CuHCF modified electrode was prepared and characterized using cyclic voltammetry. The effect of scan rate, supporting electrolyte and pH of the medium on the performance of the modified electrode was investigated. The CuHCF modified electrode exhibited good electrocatalytic activity towards the oxidation of ascorbic acid and gavea linear response4×106M to 4.9×10-4M with a correlation coefficient of 0.995). Hydrodynamic voltammetry and chronoamperometry studies for the oxidation of ascorbic acid were also carried out. The electrode was highly stable and exhibited good reproducibility. This modified electrode was also applied for the determination of ascorbic acid in commercial samples.

High Surface Area Carbon Electrodes for the Bromine Reactions in H2-Br2 Fuel Cells

The H2-Br2 system is considered as one of the viable options for large scale electrical energy storage due to faster H2 and Br2 reaction kinetics, low cost, and high round-trip efficiency. In order to improve the performance of the H2-Br2 fuel cell, carbon electrodes with high active surface area are needed. A preliminary study was conducted to synthesize and characterize the carbon nanotube based electrodes. Based on the results obtained from SEM, TEM, and EDX analysis, multi-wall carbon nanotube growth is confirmed. Also, the results from the multi-step chronoamperometry study have shown that the active areas of carbon nanotube electrodes are significantly higher than a plain carbon electrode.

Electron Transfer Reactions and Stability of Bio-Anodes with PQQ-Dependent Dehydrogenases

The performance of enzymatic electrodes for biofuel cells or bio-sensors is subject among other factors to the rate of interfacial electron transfer between the enzyme and the surface of the electrode as well as decrease in enzyme activity due to enzyme immobilization and operation. Therefore, one approach towards improving generated current, stability, and consistent reproducibility of enzymatic electrodes is to optimize the enzyme-electrode interactions. Towards this goal it has been demonstrated previously by our group that covalent attachment of multi-copper oxidase enzymes to carbonaceous electrodes through a bifunctional cross-linker, 1-Pyrenebutyric acid N-hydroxysuccinimide ester (PBSE), resulted in improved interfacial electron transfer and subsequent higher generated current relative to physisorbed enzymes on bare multi-walled carbon nanotubes (MWNT)[ 1 ].In the current work, a similar technique is applied for the immobilization of Pyrroloquinoline quinone (PQQ) dependent dehydrogenases using three cross-linkers (PBSE, N-(1-Pyrenyl) maleimide (PYMAL) and 1-Pyrenecarboxylic acid (PCA)) selected based on their similar structures to that of PBSE. PQQ-dependent dehydrogenases are of interest to the application of biofuel cells and sensors due to their high catalytic activity, insensitivity to oxygen and broader substrate specificity[ 2 ] relative to NAD+/FAD+ dependent proteins. Electrochemical characterization using linear voltammetry and potentiostatic polarization of anodes developed using soluble Pyrroloquinoline quinone-dependent Glucose dehydrogenase (sGDH-PQQ) indicate that incorporation of a cross-linker onto the anode surface results in a significant increase in generated current (Fig. 1). This result impliesthat the length of the linker “tail” determines the distance between the attached enzyme and the electrode; shorter tail – shorter hoping distance for the electrons, resulting in higher electrontransfer efficiency.Further chronoamperometry studies indicate an improvement in electrode stability and resistance to enzyme activity degradation when compared to physisorbed sGDH-PQQ on MWNT. Expanding on the close interaction of the enzyme to the electrode substrate provided by the cross-linker, this work further characterizes enzyme activity of sGDH-PQQ as well as various quinohaemoproteins in situ immobilized on MWNT-paper to determine the most effective cross-linker for improving interfacial electron transport and preserving enzyme activity when immobilized. Subsequent to the selection and incorporation of a cross-linker, heme and heme analogues are covalently attached to the surfaces of gold and MWNT electrodes via techniques including electrochemical grafting of diazonium salts possessing amide functional groups which can be used to covalently attach hemes and their analogues to the electrode (Fig. 2). The heme is a natural electron “mediator” that carries out the internal electron transfer within quinohaemoproteins. Therefore, incorporating hemes or other selected porphyrins possessing appropriate redox potential in close proximity to the enzyme could improve the electron transfer from the enzyme to the electrode. Enzymatic anodes containing immobilized hemes or heme analogues in combination with cross-linking agents are characterized for generated current, enzyme activity, and stability using various electrochemical techniques. [1] S. Brocato, C. Lau, P. Atanassov, Electrochimica Acta 2012, 61, 44-49.[2] C. Anthony, Antioxidants & Redox Signaling 2001, 3, 757-774.

Zinc-Cobalt Alloy Deposited on the Titanium Surface As Electrocatalysts for Borohydride Oxidation

The present work is focused on the investigation of the electrochemical oxidation of borohydride in alkaline solution on low-cost ZnCo alloy deposited on the titanium surface (denoted as ZnCo/Ti). The ZnCo alloy coatings with the thickness of ~5 µm were deposited on the titanium surface (1 x1 cm) via electrodeposition from the electrolyte described in Ref. [1]. Prior to ZnCo alloy deposition, the titanium plates were degreased with acetone and then pretreated in diluted H2SO4 (1:1 vol) at 90 oC for 10 s. Cobalt coatings with the thickness of ~3 µm were deposited from the same electrolyte [1] with only difference that zinc ions were excluded from the plating bath.The morphology, structure and composition of the prepared catalysts were examined by FESEM, EDS and ICP-OES. Activity of the fabricated catalysts was investigated towards the oxidation of borohydride by means of cyclic voltammetry and chronoamperometry.It was found that the ZnCo alloy coating, electrodeposited on the titanium surface, consists of ~81.3 at. % of Zn and ~16.1 at. % of Co.It has been determined that the Co/Ti and ZnCo/Ti catalysts catalyzes oxidation of H2 generated by catalytic hydrolysis of BH4 – and direct BH4 – ions oxidation. Notably, the H2 oxidation current densities measured on both catalysts are similar and reach up to 60 mA cm–2, whereas, the borohydride oxidation current densities are ~3-6 times higher on the ZnCo/Ti catalysts than those obtained on the Co/Ti catalyst. The chronoamperometry and chronopotentiometry studies also confirmed a high electrocatalytic activity of the ZnCo/Ti catalyst for the direct electro-oxidation of BH4 – ions as compared to that of Co/Ti electrode.The ZnCo/Ti catalysts are promising low-cost anode material for direct borohydride fuel cells.

Facile preparation of β-Ni(OH)2-NiCo2O4 hybrid nanostructure and its application in the electro-catalytic oxidation of methanol

A surfactant-free synthetic methodology is reported for the preparation of β-Ni(OH)2-NiCo2O4 hybrid nanostructure. For comparative study, β-Ni(OH)2-NiO, β-Ni(OH)2-Co3O4, NiCo2O4, NiO, Co3O4, and β-Ni(OH)2 were also synthesized. Materials were characterized by X-ray diffraction, nitrogen sorption, scanning electron microscopy, and transmission electron microscopy. The electrochemical oxidation of methanol is investigated at β-Ni(OH)2-NiCo2O4 modified electrode in the alkaline medium using cyclic voltammetry (CV) and chronoamperometry methods. A detailed investigation is made for the electro-catalytic oxidation of methanol by varying several reaction parameters such as potential scan rate, methanol concentration, etc. Mechanism of methanol oxidation is proposed based on the CV and double steps chronoamperometry studies. β-Ni(OH)2-NiCo2O4 modified electrode exhibited comparatively higher electro-catalytic activity in the methanol oxidation when compared to other modified electrodes investigated in this study.

Effect of support materials on the performance of direct ethanol fuel cell anode catalyst

Pt–Ru catalysts supported on mesoporous carbon nitride (MCN), multiwall carbon nano tubes (MWCNTs), treated MWCNTs (t-MWCNTS) and Vulcan-XC were prepared using co-impregnation reduction method for the oxidation of ethanol in direct ethanol fuel cell (DEFC) to study the effect of support material. The MCN support was prepared using SBA-15 as template and t-MWCNTs were prepared by refluxing in HNO3 and H2SO4 mixture (1:3) using MWCNTs. XRD shows the formation of Pt–Ru bi-metallic catalyst with size ranges from 7 to 17 nm using different supports. The catalyst and its supports were characterized by physically and electrochemically. Linear sweep voltammetry, cyclic voltammetry and chrono amperometry studies of the above systems reveal that MCN supported Pt–Ru catalyst shows higher electro-catalytic activity towards ethanol oxidation compared to Pt–Ru in treated t-MWCNTs, MWCNts and Vulcan-XC supports. The performance of DEFC based on maximum power density is found to be in the order Pt–Ru/MCN > Pt–Ru/t-MWCNTs > Pt–Ru/MWCNTs > Pt–Ru/Vulcan-XC. The Pt–Ru/MCN shows highest power density of 61.1 mW cm−2 at 100 °C, 1 bar pressure with catalyst loading of 2 mg cm−2 using 2 M ethanol feed.