CNTs/Ni-W/CC复合电极的构筑及电解水析氢催化性能

Preparation of CNTs/Ni-W/CC composite electrode and its electrocatalytic activity for hydrogen evolution reaction

在碳布材料(CC)表面首先电沉积W原子分数约为13%的Ni-W合金,再通过化学气相沉积(CVD)在其表面生长碳纳米管(CNTs),构筑出一种自支撑CNTs/Ni-W/CC复合电极。电化学测试表明:该复合电极在1 mol/L NaOH水溶液中表现出良好的电解水析氢(HER)催化性能。在不同温度下保温2 h所获样品中,900°C保温后的样品具有最佳析氢催化活性,其在10 mA/cm2阴极电流密度下的HER过电位为118.2 mV,Tafel斜率为97.4 mV/dec,并且其阴极电流密度在较高的阴极过电位下可超越商用Pt/C材料。此外,在持续的电催化反应工作过程中,该样品的HER催化活性可长期保持稳定。

A Ni-W alloy containing about 13at.%of tungsten was deposited on carbon cloth(CC)by electrodeposition initially,and then carbon nanotubes(CNTs)were grown thereon by chemical vapor deposition(CVD),fabricating a selfsupported CNTs/Ni-W/CC composite electrode.The results of electrochemical test showed that the composite electrode exhibited good catalytic performance for hydrogen evolution reaction(HER)in 1 mol/L NaOH aqueous solution.The CNTs/Ni-W/CC composite electrode fabricated at 900°C(the temperature of heat preservation in CVD)showed the best electrocatalytic activity among all the prepared samples.Its overpotential was 118.2 mV at a cathodic current density of 10 mA/cm2 and its Tafel slop was 97.4 mV/dec.The cathodic current density of this composite electrode could exceed that of commercial Pt/C material at a relatively high overpotential.This composite electrode also showed good long-term stability for HER.