Guo Dingyi, Qi Jing, Zhang Wei, Cao Rui
School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, P.R. China.
Department of Chemistry, Renmin University of China, Beijing, 100872, P.R. China.
ChemSusChem. 2017 Jan 20;10(2):394-400. doi: 10.1002/cssc.201601151. Epub 2016 Nov 21.
The slow kinetics of water oxidation greatly jeopardizes the efficiency of water electrolysis for H production. Developing highly active water oxidation electrodes with affordable fabrication costs is thus of great importance. Herein, a Ni Fe surface species on Ni metal substrate was generated by electrochemical modification of Ni in a ferrous solution by a fast, simple, and cost-effective procedure. In the prepared Ni Fe catalyst film, Fe was incorporated uniformly through controlled oxidation of Fe cations on the electrode surface. The catalytically active Ni originated from the Ni foam substrate, which ensured the close contact between the catalyst and the support toward improved charge-transfer efficiency. The as-prepared electrode exhibited high activity and long-term stability for electrocatalytic water oxidation. The overpotentials required to reach water oxidation current densities of 50, 100, and 500 mA cm are 276, 290, and 329 mV, respectively.
水氧化反应的缓慢动力学极大地损害了水电解制氢的效率。因此，开发具有可承受制造成本的高活性水氧化电极至关重要。在此，通过一种快速、简单且经济高效的方法，在亚铁溶液中对镍进行电化学改性，在镍金属基底上生成了镍铁表面物种。在所制备的镍铁催化剂薄膜中，通过控制电极表面铁阳离子的氧化，铁被均匀地掺入。具有催化活性的镍源自泡沫镍基底，这确保了催化剂与载体之间的紧密接触，从而提高了电荷转移效率。所制备的电极在电催化水氧化方面表现出高活性和长期稳定性。达到50、100和500 mA cm水氧化电流密度所需的过电位分别为276、290和329 mV。
