Wang Meng, Ma Wansen, Lv Zepeng, Liu Dong, Jian Kailiang, Dang Jie
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China.
Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials, Chongqing University, Chongqing 400044, PR China.
J Phys Chem Lett. 2021 Feb 18;12(6):1581-1587. doi: 10.1021/acs.jpclett.0c03804. Epub 2021 Feb 4.
Preparation of high-activity and earth-abundant bifunctional catalysts for efficient electrochemical water splitting are crucial and challenging. Herein, Co-doped NiN nanosheets loaded on nickel foam (Co-NiN) were synthesized. The as-prepared Co-NiN exhibits excellent catalytic activity toward both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in alkaline media. Density functional theory (DFT) calculation reveals that Co-NiN with redistribution of electrons not only can facilitate the HER kinetics but also can regulate intermediates adsorption energies for OER. Specifically, the Co-NiN exhibits high efficiency and stable catalytic activity, with an overpotential of only 30 and 270 mV at a current density of 10 mA cm for the HER and OER in 1 M KOH, respectively. This work provides strong evidence to the merit of Co doping to improve the innate electrochemical performance in bifunctional catalysts, which might have a common impact in many similar metal-metal nitride electrocatalysts.
制备用于高效电化学水分解的高活性且储量丰富的双功能催化剂至关重要且具有挑战性。在此，合成了负载在泡沫镍上的钴掺杂氮化镍纳米片（Co-NiN）。所制备的Co-NiN在碱性介质中对析氢反应（HER）和析氧反应（OER）均表现出优异的催化活性。密度泛函理论（DFT）计算表明，电子重新分布的Co-NiN不仅可以促进HER动力学，还可以调节OER的中间体吸附能。具体而言，Co-NiN表现出高效且稳定的催化活性，在1 M KOH中，HER和OER在电流密度为10 mA cm时的过电位分别仅为30和270 mV。这项工作为钴掺杂在改善双功能催化剂固有电化学性能方面的优点提供了有力证据，这可能对许多类似的金属-金属氮化物电催化剂产生普遍影响。
