摘要
采用快速凝固与脱合金相结合的方法制备了纳米多孔Ni,经热处理氧化获得纳米多孔NiO,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和氮气吸附⁃脱附仪(BET)对纳米多孔Ni和NiO的物相、形貌结构和孔径分布进行了表征,并通过循环伏安、稳态极化和电化学阻抗分析研究了电极的电催化析氧性能.结果表明,由Ni30Al70所得纳米多孔Ni具有多层次纳米多孔结构,在10 mA/cm^2电流密度下析氧过电位仅为224 mV,交换电流密度为0.63297 mA/cm^2,表观活化自由能为40.297 kJ/mol,经1000次循环后,过电位降低了5 mV(j=10 mA/cm^2),表现出良好的催化稳定性和耐久性;热处理氧化降低了NiO的比表面积与电化学活性面积,平衡电位下扩散传质速率明显减小,析氧活性较Ni电极有所下降.
Nanoporous Ni was prepared by a combined method of rapid quenching and dealloying,and then the prepared samples were heat-treated to synthesize the nanoporous NiO.The phase,morphology,microstructure and pore-size distribution of nanoporous Ni and NiO were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and N2 adsorption-desorption analysis,respectively.Their electrochemical performance was investigated by cyclic voltammetry,electrochem-ical stea-dy-state polarization and electrochemical impendence spectroscopy(EIS).The results show that the nanoporous Ni obtained from Ni30 Al70 has multi-stage nanoporous structure,when the current density is 10 mA/cm^2,the oxygen evolution overpotential is only 224 mV,the exchange current density is 0.63297 mA/cm^2,and the apparent activation free energy is 40.297 kJ/mol;after 1000 cycles of voltammetry,the overpotential decreases by 5 mV(j=10 mA/cm^2),showing fine catalysis stability and durability.
作者
任向荣
周琦
REN Xiangrong;ZHOU Qi(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第1期162-174,共13页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:51661018)资助~~
关键词
快速凝固
脱合金化
纳米多孔镍
电催化活性
析氧反应
Rapid quenching
Dealloying
Nanoporous Ni
Electrocatalytic activity
Oxygen evolution reaction
作者简介
联系人:周琦,女,教授,主要从事新型能源材料的制备及性能研究.E⁃mail:zhouxq301@sina.com。
