Co-reporter:Qingfeng Yi, Lizhi Sun, Xiaoping Liu, Huidong Nie
Fuel 2013 Volume 111() pp:88-95
Publication Date(Web):September 2013
DOI:10.1016/j.fuel.2013.04.051
•PdNi nanoparticles were electrodeposited on MWCNT modified with β-CD.•High dispersity of PdNi nanoparticles on the β-CD-MWCNT.•Electroactivity of PdNi/β-CD-MWCNT for oxidation of C2–C4 alcohols was assessed.•High electrocatalytic activity of the PdNi/β-CD-MWCNT for the alcohol oxidations.β-Cyclodextrin (β-CD) was grafted to the surface of multi-walled carbon tubes (MWCNTs) immobilized on Ti plates to obtain the β-CD-MWCNT/Ti electrode by using the self-assembly method. Binary Pd–Ni nanoparticles were then electrodeposited on the β-CD-MWCNT/Ti to synthesize the PdNi/β-CD-MWCN/Ti electrode. As a comparison, PdNi/MWCNT/Ti and PdNi/Ti electrodes were also prepared under the same condition. SEM images show that compared to the PdNi/MWCNT/Ti and PdNi/Ti, the binary PdNi nanoparticles on the β-CD-MWCNT/Ti are more highly dispersed with smaller sizes of 90–130 nm. Electrocatalytic activity of the as-synthesized electrodes towards electrooxidation of ethanol, propanol and butanol in alkaline media was investigated. Results show that the PdNi/β-CD-MWCNT/Ti electrode exhibits very high electroactivity for the alcohol oxidations and presents much enhanced performance compared with other two electrodes. Among the three alcohols, ethanol displays the greatest activity with the highest oxidation current density while butanol shows the lowest oxidation current density.Graphical abstractMWCNTs modified with β-cyclodextrin present a dramatic enhancement on the dispersing of nanoparticles.
Co-reporter:Qingfeng Yi;Gekunkun Zuo
Chinese Journal of Chemistry 2012 Volume 30( Issue 1) pp:151-156
Publication Date(Web):
DOI:10.1002/cjoc.201180457
Abstract
A nanoporous Pt particles-modified Ti (nanoPt/Ti) electrode was prepared through a simple hydrothermal method using aqueous H2PtCl6 as a precursor and formaldehyde as a reduction agent. The nanoPt/Ti electrode was then modified with limited amounts of tin particles generated by cyclic potential scans in the range of −0.20 to 0.50 V in a 0.01 mol·L−1 SnCl2 solution, to synthesize a Sn-modified nanoporous Pt catalyst (Sn/nanoPt/Ti). Electroactivity of the nanoPt/Ti and Sn/nanoPt/Ti electrodes towards formaldehyde oxidation in a 0.5 mol·L−1 H2SO4 solution was evaluated by cyclic voltammetry and chronoamperometry. Electrooxidation of formaldehyde on the nanoPt/Ti electrode takes place at a potential of 0.45 V and then presents high anodic current densities due to the large real surface area of the nanoPt/Ti electrode. The formaldehyde oxidation rate is dramatically increased on the Sn/nanoPt/Ti electrode at the most negative potentials, where anodic formaldehyde oxidation is completely suppressed on the nanoPt/Ti electrode. Chronoamperogramms (CA) of the Sn/nanoPt/Ti electrode display stable and large quasi-steady state current densities at more negative potential steps. Amperometric data obtained at a potential step of 100 mV show a linear dependence of the current density for formaldehyde oxidation upon formaldehyde concentration in the range of 0.003 to 0.1 mol·L−1 with a sensitivity of 59.29 mA·cm−2 (mol·L−1)−1. A detection limit of 0.506 mmol·L−1 formaldehyde was found. The superior electroactivity of the Sn/nanoPt/Ti electrode for formaldehyde oxidation can be illustrated by a so-called bifunctional mechanism which is involved in the oxidation of poisoning adsorbed CO species via the surface reaction with OH adsorbed on neighboring Sn sites.
Co-reporter:Qingfeng Yi, Fenjuan Niu, Lei Li, Renlian Du, Zhihua Zhou, Xiaoping Liu
Journal of Electroanalytical Chemistry 2011 Volume 654(1–2) pp:60-65
Publication Date(Web):1 May 2011
DOI:10.1016/j.jelechem.2011.01.031
Silver nanoparticles (nanoAg) were hydrothermally prepared through the reduction of the complex Ag+–EDTA by polyethylene glycol as the reduction agent and deposited on the titanium surface to form a nanoporous network texture which possesses considerable numbers of active sites. Electrocatalytic activity of the nanoAg electrode towards hydrogen peroxide reduction in 1 mol L−1 NaOH solution was assessed utilizing cyclic voltammetry (CV), linear scanning voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). At the nanoAg electrode, hydrogen peroxide reduction in 1 mol L−1 NaOH took place at a potential of −0.05 V (vs. SCE) and presented considerable large current density of hydrogen peroxide reduction. Cyclic voltammetric responses of the nanoAg electrode showed a fast electro-reduction process of hydrogen peroxide at the initial stage of hydrogen peroxide reduction activation region. Chronoamperometric data on the nanoAg electrode presented stable reduction currents of hydrogen peroxide which exhibited a linear increment with the increasing hydrogen peroxide concentration in the range of 0–0.1 mol L−1. Further, EIS data were obtain at various hydrogen peroxide concentrations and showed significantly low charge transfer resistances for hydrogen peroxide reduction on the nanoAg electrode. Results reveal that the nanoAg electrode of the present investigation is a highly efficient and stable electrocatalyst for hydrogen peroxide reduction in alkaline media.Research highlights► Novel nanoporous silver particles (nanoAg) were hydrothermally prepared. ► Electro-activity of the nanoAg towards H2O2 reduction in alkaline media was assessed. ► Extremely high stable reduction current of H2O2 on the nanoAg catalyst. ► Significantly low charge transfer resistances for H2O2 reduction on the nanoAg.
Co-reporter:Qingfeng Yi, Fengjuan Niu, Lizhi Sun
Fuel 2011 Volume 90(Issue 8) pp:2617-2623
Publication Date(Web):August 2011
DOI:10.1016/j.fuel.2011.03.038
Novel porous Pd particles (nanoPd–PEG, nanoPd–PEG–EDTA, nanoPd–HCHO–EDTA, nanoPd–EG, nanoPd–HCHO and nanoPd–EG–EDTA) were synthesized by a hydrothermal method using different reduction agents in the absence and presence of EDTA and investigated as electrocatalysts for ethanol oxidation in alkaline solutions. Results showed that PdCl2 was hydrothermally reduced to nano-scale palladium particles and a three-dimensional texture was formed for Pd particles. Presence of EDTA was favorable for the formation of Pd nanoparticles with small sizes of ca. 70 nm. Ethanol oxidation on the present Pd catalysts took place at a more negative anodic potential in 1 M NaOH solution. Among the electrocatalysts investigated, the electrocatalytic activity of the nanoPd–HCHO–EDTA was the greatest, which was characterized by the largest anodic peak current density of 151 mA cm−2 and lowest onset oxidation potential of −0.788 V (vs. SCE) for the positive scan. Very low charge transfer resistances on the nanoPd–HCHO–EDTA in 1 M NaOH containing various concentrations of ethanol were obtained according to the analysis for electrochemical impedance spectra (EIS). The prepared porous Pd catalysts were promising alternatives to Pt electrodes applied in alkaline direct alcohol fuel cells.
Co-reporter:Qingfeng Yi, Fengjuan Niu, Wenqiang Yu
Thin Solid Films 2011 Volume 519(Issue 10) pp:3155-3161
Publication Date(Web):1 March 2011
DOI:10.1016/j.tsf.2010.12.241
The electrocatalysis of the oxidation of hydrazine, formaldehyde and glucose on a nanoporous Pd-modified TiO2 electrode, prepared by the hydrothermal process, was investigated in 0.1 M NaOH solutions. The electrocatalytic activity of the Pd-modified TiO2 electrode for the electrochemical oxidation of hydrazine, formaldehyde and glucose is characterized by the low onset potentials of −0.80, −0.70 and −0.85 V (vs Ag,AgCl), respectively. Compared to the oxidation of formaldehyde and glucose, the hydrazine oxidation on the Pd-modified TiO2 presents the highest anodic oxidation current densities, showing that the Pd-modified TiO2 electrode is more electro-active for the hydrazine oxidation than for the oxidation of formaldehyde and glucose. Chronoamperograms at different concentrations of hydrazine and formaldehyde showed that the Pd-modified TiO2 electrode is a promising electrochemical sensor for the detection of hydrazine with a sensitivity of 0.554 mA cm−2 mM−1 and a detection limit of 0.023 mM, and for the detection of formaldehyde with a sensitivity of 0.20667 mA cm−2 mM−1 and a detection limit of 0.015 mM. However, it was found from the chronoamperometric responses at various glucose concentrations that a linear plot of the anodic oxidation current density versus glucose concentration developed only in the range of 7–35 mM glucose while an obvious deviation from the linear relationship was observed at both low and large glucose concentrations. Results show that the prepared Pd-modified TiO2 electrode could be applied to the direct liquid (hydrazine, formaldehyde, and glucose) fuel cells as an effective anodic catalyst, in addition to be a promising electrochemical sensor for the detection of hydrazine and formaldehyde.
Co-reporter:Qingfeng Yi;Fengjuan Niu
Rare Metals 2011 Volume 30( Issue 4) pp:
Publication Date(Web):2011 August
DOI:10.1007/s12598-011-0393-3
Titanium-supported nanoporous palladium catalyst (Pd/Ti) was prepared by a hydrothermal method using PdCl2 as a precursor, ethylenediamine tetraacetic acid (EDTA) as a ligand, and formaldehyde as a reduction agent. Complex Pd-EDTA2− is favorable for the formation of Pd particles with nanoscale sizes. The electroactivity of the Pd/Ti catalyst towards the electroreduction of hydrogen peroxide in 1 mol/L NaOH solution was evaluated by voltammetric techniques. Both linear scan voltammetric and chronoamperometric data present significantly large steady-state reduction current density of the hydrogen peroxide electroreduction on the prepared Pd/Ti catalyst. The results show that the prepared Pd/Ti catalyst is an effective electrocatalyst for the electroreduction of hydrogen peroxide in alkaline media.
Co-reporter:Qingfeng Yi;Lei Li;Wenqiang Yu;Xiaoping Liu;Zhihua Zhou;Huidong Nie
Rare Metals 2010 Volume 29( Issue 1) pp:26-31
Publication Date(Web):2010 February
DOI:10.1007/s12598-010-0005-7
From an aqueous mixture of Ag(I)-EDTA complex and Ni(II) nitrate, silver and nickel particles were co-deposited on the surface of titanium substrates by the hydrothermal method using hydrazine hydrate as a reduction agent. The prepared titanium-supported nano-scale Ag and Ag-Ni particles (nano Ag/Ti, nano Ag86Ni14/Ti, nano Ag77Ni23/Ti, and nano Ag74Ni26/Ti) exhibit nanoporous 3D network textures. Their electrocatalytic activity towards hydrazine oxidation in alkaline solutions was evaluated by cyclic voltammetry and chronoamperometry. The results show that the four samples present a low onset potential of ca. −0.60 V vs. SCE and considerably high and stable anodic current densities for hydrazine oxidation. Among them, the nano Ag86Ni14/Ti electrode exhibits the highest anodic current density towards hydrazine oxidation, showing an increment of electro-active sites on the nano Ag86Ni14/Ti due to the addition of Ni to Ag particles.
Co-reporter:Qingfeng Yi, Wenqiang Yu
Journal of Electroanalytical Chemistry 2009 Volume 633(Issue 1) pp:159-164
Publication Date(Web):1 August 2009
DOI:10.1016/j.jelechem.2009.05.008
A nanoporous gold particles modified titanium electrode (Au/Ti) was prepared by using a hydrothermal method. Gold nanoparticles were stably immobilized on the Ti surface from a mixture of aqueous HAuCl4/polyethylene glycol (PEG) to form a nanoporous network texture. Electrocatalytic activity of the Au/Ti towards hydrazine oxidation in 1 M NaOH solution was assessed utilizing cyclic voltammetry (CV), linear scanning voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). At the Au/Ti electrode, hydrazine oxidation in 1 M NaOH took place at a potential of −0.55 V (vs. Ag, AgCl) which was 0.53 V less than polycrystalline Au electrode. The Au/Ti electrode also presented much larger current density of hydrazine oxidation than Au electrode. Cyclic voltammetric responses of the Au/Ti electrode showed an irreversible electro-oxidation process of hydrazine. Linear plots of the reduction peak current density from the CVs of the Au/Ti vs. hydrazine concentration provided a potential detection of low concentration hydrazine. The kinetic parameters such as the number of electrons transferred in rate-determining step and total numbers of electrons involved in the hydrazine oxidation were determined using CVs and LSVs. CVs at the Au/Ti electrode also illustrated (relatively) weak interactions of hydrazine with electrode surface at all stages of the hydrazine oxidation process. Further, EIS data showed significantly high electrocatalytic activity of the Au/Ti electrode for hydrazine oxidation in alkaline solutions.
Co-reporter:Qingfeng Yi;Wenqiang Yu
Microchimica Acta 2009 Volume 165( Issue 3-4) pp:381-386
Publication Date(Web):2009 June
DOI:10.1007/s00604-009-0148-0
A novel Ti-supported gold catalyst (nanoAu/Ti) with a nanoporous 3D texture has been fabricated using a hydrothermal method. Au particles were stably deposited on the Ti surface from the mixture of aqueous tetrachlororoauric acid and polyethylene glycol at 180 °C. Voltammetry (CV) and chronoamperometry were used to characterize the nanoAu/Ti electrode and assess its electroactivity towards glucose oxidation. Compared to polycrystalline Au, the nanoAu/Ti electrode shows similar CV profiles in alkaline solution. However, in an alkaline solution containing 10 mM glucose, the nanoAu/Ti electrode presents much higher anodic current densities and a more negative onset potential (ca. −0.75 V) for glucose oxidation than a bulk Au electrode. Analysis for Tafel plot of the nanoAu/Ti electrode shows that electro-oxidation of glucose takes place via a one-electron rate-determining step. Results indicate a high and (relatively) stable electrocatalytic activity of the nanoAu/Ti for glucose oxidation.
Co-reporter:Qing-Feng YI;Wu HUANG;Wen-Qiang YU;Lei LI ;Xiao-Ping LIU
Chinese Journal of Chemistry 2008 Volume 26( Issue 8) pp:1367-1372
Publication Date(Web):
DOI:10.1002/cjoc.200890249
Abstract
Novel titanium-supported Ni-Sn/Ti electrodes (Ni8Sn/Ti, Ni7Sn3/Ti and Ni/Ti) have been prepared using a hydrothermal method by a one step process. The scanning electron microscopy (SEM) images show that the catalyst particles are present as nano-scale flakes. Their electrochemical activity for methanol oxidation in 1 mol·L−1 NaOH was evaluated using voltammetric techniques, chronoamperometric measurements and electrochemical impedance spectra (EIS). It was found that the Ni8Sn/Ti electrode presents higher anodic currents and lower onset potential for methanol oxidation than Ni7Sn3/Ti, Ni/Ti and polycrystalline Ni electrodes. The EIS data indicate that under conditions of various anodic potentials and methanol concentrations, the Ni8Sn/Ti electrode displays significantly lower charge transfer resistances and high electrocatalytic activity towards methanol oxidation.
Co-reporter:Qingfeng Yi;Jingjing Zhang;Aicheng Chen
Journal of Applied Electrochemistry 2008 Volume 38( Issue 5) pp:695-701
Publication Date(Web):2008 May
DOI:10.1007/s10800-008-9490-x
Bimetallic platinum–tin nanoparticles were co-deposited on a titanium surface using a simple one step hydrothermal method process. The electrochemical catalytic activity of this titanium-supported nanoPtSn/Ti electrode towards the oxidation of formic acid and methanol in 0.5 M H2SO4 was evaluated by voltammetric techniques, chronoamperometric responses and electrochemical impedance spectra (EIS). According to the cyclic voltammograms of the oxidation of both formic acid and methanol, the nanoPtSn/Ti presents high anodic current densities and low onset potentials. Potential-time transient measurements show that the nanoPtSn/Ti exhibits high steady-state current densities for the oxidation of both formic acid and methanol. The EIS data indicate that the nanoPtSn/Ti presents very low electrochemical impedance values, showing that for the oxidation of both formic acid and methanol, low charge transfer resistances are present on the nanoPtSn/Ti catalyst. This confirms the high electrocatalytic activity of the nanoPtSn/Ti for the formic acid and methanol oxidation.
Co-reporter:Qingfeng Yi, Aicheng Chen, Wu Huang, Jingjing Zhang, Xiaoping Liu, Guorong Xu, Zhihua Zhou
Electrochemistry Communications 2007 Volume 9(Issue 7) pp:1513-1518
Publication Date(Web):July 2007
DOI:10.1016/j.elecom.2007.02.014
Novel titanium-supported nanoporous network bimetallic Pt–Ir/Ti electrocatalysts (S1:Pt59Ir41/Ti, S2:Pt44Ir56/Ti, S3:Pt22Ir78/Ti) have been successfully fabricated by the hydrothermal process. The nanoparticles of Pt and Ir were deposited on the titanium substrates in the presence of formaldehyde as a reduction agent. The electrocatalytic activity of these electrocatalysts towards formic acid oxidation in 0.5 M H2SO4 + 0.5 M HCOOH solutions was investigated using cyclic voltammograms (CVs), linear sweep voltammograms (LSVs), chrono amperometry and electrochemical impedance spectroscopy (EIS). The CVs of S1, S2 and S3 exhibit two anodic peaks in the forward scan and one anodic peak in the reverse scan which are similar to the pure Pt. Their LSVs show that the three samples present significantly high current densities of formic acid oxidation compared to the Pt electrode. It is observed from the chrono amperometric measurements at potential 600 mV that the sample S2 delivers a steady-state current density that is 545 times larger than that for the pure Pt electrode. EIS analysis shows that the impedances on both the imaginary and real axes of S1, S2 and S3 are much lower than those of the pure Pt. Among the three samples (S1, S2 and S3), S2 exhibits the highest electrocatalytic activity towards the formic acid oxidation.
