碳载钴镍合金纳米电极的制备表征与电催化性能

Preparation and characterization of carbon supported CoNi alloy nanoparticles electrode and their electrocatalytic properties

采用电化学方法在玻碳(GC)表面电沉积CoNi合金纳米粒子,成功制得碳载CoNi合金纳米电极(CoNi/GC)。SEM结果显示,CoNi粒子呈十八面体结构,粒径约100nm,分布较均匀。选区电子衍射(SAED)结果显示,CoNi合金纳米粒子为单晶结构。XPS结果显示,金属态的Co(0)和Ni(0)占主导地位。性能测试结果表明:CoNi/GC不但对亚硝酸钠具有较好的催化性能,相对于本体Co和本体Ni,CoNi/GC的起始还原电位(Ei)正移约90mV,还原峰电流(jp)增大6～14倍。而且对氧还原亦有较好的电催化活性,CoNi/GC的峰电流密度(jp)和动力电流密度(jk)分别是GC电极的1.7和5.2倍。

CoNi alloy nanoparticles were synthesized on glassy carbon（GC）electrode（CoNi/GC）by electrochemical deposition.SEM images showed that the prepared CoNi alloy nanoparticles were 18-facet polyhedra with an average particles size of 100 nm,dispersed on the GC electrode surfaces uniformly.The selected area electron diffraction（SAED）pattern showed that CoNi alloy nanoparticles were single crystals.X-ray photoelectron spectroscopy（XPS）showed that the Co（0）and Ni（0）were dominant.The electrocatalytical activities for nitrite reduction of bulk Co,bulk Ni and CoNi/GC electrodes were investigated by cyclic voltammetry（CV）.Onset potential（Ei）of nitrite reduction on CoNi/GC electrode was positively shifted 90 mV,and peak current density（jp）was 6—14 times higher than those of bulk Co and bulk Ni electrode.CoNi/GC electrode also showed an enhancement of electrocatalytical activity towards oxygen reduction reaction,of which peak current density（jp）was 1.7 times and dynamic current density（jk）was 5.2 times higher than those of GC electrode.