摘要
为开发新型廉价高效的析氢材料,用恒电流复合电沉积方法制备了(Ni-Mo)-TiO2复合电极,讨论了TiO2悬浮量和电沉积时间对电极催化析氢性能的影响.用XRD和SEM对电极的晶体结构和表面形貌进行了表征,以稳态极化曲线对电极的催化析氢特性进行了评价.结果表明,(Ni-Mo)-TiO2电极是纳米TiO2粒子相和纳米晶Ni-Mo固溶体相构成的复合电极.电极具有较高的催化析氢活性.在25℃、0.5mol.dm-3H2SO4溶液中其表观交换电流密度是Ni-Mo合金电极的2.6倍,是Ni电极的60倍.在电流密度为100mA·cm-2时,电极电势相对于Ni-Mo电极正移了120mV,相对于Ni电极正移了542mV.催化活性的提高源于反应机理的改变,表观活化吉布斯自由能相对于Ni-Mo合金电极降低了24.48kJ·mol-1.
（Ni-Mo）-TiO2 composite coating was prepared by electrolytic co-deposition of Ni-Mo ally and TiO2 particles on a Cu substrate from a solution in which TiO2 nano particles （P-25） were suspended by stiring. Effects of concentration of TiO2 particles suspended in the plating bath and depositing time on the catalytic activity for the hydrogen evolution reaction （HER） were discussed. The surface morphology and microstructure of （Ni-Mo）-TiO2 coating were observed by SEM and XRD. Catalytic activity for HER was evaluated on the basis of electrochemical steady-state polarization curves in 0.5 mol·dm-3 H2SO4 solution. Results indicate that the （Ni-Mo）-TiO2 electrode consists of TiO2 crystalline and Ni-Mo nano crystalline in solid solution. The composite electrode has better catalytic activity compared with Ni-Mo and Ni alloy electrodes. The polarization over potential for hydrogen evolution of the （Ni-Mo）-TiO2 electrode is 120 mV lower than that of Ni-Mo electrode and is 542 mV lower than that of Ni electrode at the current density of 100 mA·cm^-2. The apparent exchange current density of the composite electrode is 2.6 times that of the Ni-Mo electrode,and 60 times that of Ni electrode. The increasing catalytic activity for HER of the （Ni-Mo）-TiO2 composite electrode is mainly due to the change in the reaction mechanism. The apparent Gibbs free energy of activation of the composite electrode is 24.48 kJ·mol^-1 lower than that of Ni-Mo electrode.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2009年第6期793-796,共4页
Materials Science and Technology
基金
廊坊师范学院重点资助研究项目(LSZZ200902)
