LAUSR

Exploring and designing bi-functional catalysts with earth-abundant elements that can work well for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline medium are of significance for producing clean fuel to relieve energy and environment crisis. Here, a novel Ni/NiO monolithic electrode was developed by a facile and cost-effective acid promoted activation of Ni foam. After the treatment, this obtained monolithic electrode with a layer of NiO on its surface demonstrates rough and sheet-like morphology, which not only possesses larger accessible surface area but also provides more reactive active sites. Compared with powder catalysts, this monolithic electrode can achieve intimate contact between the electrocatalyst and the current collector, which will alleviate the problem of pulverization and enable the stable function of the electrode. It can be served as an efficient bi-functional electrocatalyst with an overpotential of 160 mV for HER and 290 mV for OER to produce current densities of 10 mA cm−2 in the alkaline medium. And it maintains benign stability after 5,000 cycles, which rivals many recent reported noble-metal free catalysts in 1.0 mol L−1 KOH solution. Attributed to the easy, scalable methodology and high catalytic efficiency, this work not only offers a promising monolithic catalyst but also inspires us to exploit other inexpensive, highly efficient and self-standing noble metalfree electrocatalysts for scale-up electrochemical water-splitting technology.摘要开发和制备碱性条件下的非贵金属析氢和析氧催化剂对于缓解能源和环境危机至关重要. 本文利用一种简单的酸活化方法, 制备出了一种基于泡沬镍的镍/氧化镍一体化电极. 由于其粗糙及类片层的表面结构使得制备出的电极具有大的比表面积和更多的表面反应活性位点. 同时, 与粉末催化剂相比, 此一体化电极可实现催化剂和集流体之间的良好接触, 在一定程度上缓解催化剂的脱落问题, 保证了电极的稳定性. 当用作双功能催化剂时, 其表现出了优异的催化活性和良好的稳定性. 此法简单且易规模化, 可以为制备其他非贵金属催化剂提供思路.