摘要
Non-noble-metal electrode materials with high durability and efficiency have become the frontiers of energy conversion and storage fields.However,conventional electrode materials often show high overpotential and low conductivity.To solve this problem,we fabricate a NiMoxCo2−x layered double hydroxide(LDH)/Ni foam(NF)product through a facile hydrothermal route.The as-prepared NiMo-Co-LDH/NF catalyst possesses an overpotential of 123 mV for hydrogen evolution reaction(HER)at 10 mA cm^−2 and 279 mV for oxygen evolution reaction(OER)at 20 mA cm^−2.The as obtained product exhibits excellent overall water splitting performances.Meanwhile,as the electrode material for supercapacitor,it delivers high specific capacitance and excellent cyclic performance.The asymmetric supercapacitor assembled with NiMoCo-LDH/NF//active carbon exhibits 93%of its initial capacity after 8000 cycles.
本文通过调控Ni,Mo,Co三种元素的摩尔比得到一系列高效双功能电催化剂.其中,Co元素特定的氧吸附位点(Co^2+-O-Co^3+)可有效提高催化剂的活性.Mo元素在温和反应条件下具有较好的氧化还原能力.Ni是另一种高活性过渡金属.与其他材料结合可有效增强催化剂的氧化还原活性和储氧能力.所制备的NiMoCo层状双金属氢氧化物(NiMoCo-LDH)催化剂在10 mA cm^-2时析氢反应(HER)过电势为123 mV,20 mA cm^-2时析氧反应(OER)过电势为251 mV.该材料还表现出优异的全解水性能,为构筑过渡金属氢氧化物电催化剂提供了崭新思路.同时,所制备的电极材料用作超级电容器正极时也表现出优异的性能.在1 A g^-1的电流密度下,NiMoCo-LDH电极拥有642.1 C g^-1的比容量.组装的NiMoCoLDH//AC非对称超级电容器在功率密度为2695 W kg^-1时能量密度为141 Wh kg^-1,经过8000次充放电后仍保持初始容量的93%.
作者
Hengqi Liu
Depeng Zhao
Ying Liu
Yongli Tong
Xiang Wu
Guozhen Shen
刘恒岐;赵德鹏;刘颖;佟永丽;武祥;沈国震(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang,110870,China;State Key Laboratory for Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing,100083,China)
基金
Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology(191010-K)
the Education Department Funding of Liaoning Province(LJGD2019001)
the Funding of Science and Technology Bureau,Shenyang City(RC190138)。
