Ma Yan, Chu Jiayu, Li Zhennan, Rakov Dmitrii, Han Xijiang, Du Yunchen, Song Bo, Xu Ping
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China.
Small. 2018 Dec;14(52):e1803783. doi: 10.1002/smll.201803783. Epub 2018 Nov 23.
Developing facile routes for fabricating highly efficient oxygen evolution reaction (OER) electrocatalysts is in great demand but remains a great challenge. Herein, a novel molten salt decomposition method to prepare 3D metal nitrate hydroxide (MNH, M = Ni, Co, and Cu) nanoarrays homogenously grown on different conductive substrates, especially on nickel foam (NF) for OER applications, is reported. Compared with the as-prepared CoNH/NF and CuNH/NF, NiNH/NF presents a superior electrocatalytic OER activity and stability in an alkaline solution, with a very low overpotential of only 231 mV versus a reversible hydrogen electrode to deliver a geometrical catalytic current density of 50 mA cm and a low Tafel slope of 81 mV dec , outperforming most reported transition metal compound catalysts. Structural investigation after the OER process reveals the morphology integrity of the nanoarrays but the formation of metal oxyhydroxide (for NiNH and CoNH) or oxide (for CuNH) as the likely real active species. These metal nitrate hydroxide non-noble metal electrocatalysts can be prepared by an economical and simple method, with enhanced intrinsic activity and long-term stability and durability, which might be new candidates for energy conversion and storage applications.
开发用于制备高效析氧反应（OER）电催化剂的简便方法具有迫切需求，但仍然是一项巨大挑战。在此，报道了一种新颖的熔盐分解方法，用于制备在不同导电基底上均匀生长的三维金属硝酸氢氧化物（MNH，M = Ni、Co和Cu）纳米阵列，特别是用于OER应用的泡沫镍（NF）上的纳米阵列。与制备的CoNH/NF和CuNH/NF相比，NiNH/NF在碱性溶液中表现出优异的电催化OER活性和稳定性，相对于可逆氢电极，过电位非常低，仅为231 mV，可提供50 mA cm的几何催化电流密度，塔菲尔斜率低至81 mV dec，优于大多数已报道的过渡金属化合物催化剂。OER过程后的结构研究揭示了纳米阵列的形态完整性，但形成了金属羟基氧化物（对于NiNH和CoNH）或氧化物（对于CuNH）作为可能的实际活性物种。这些金属硝酸氢氧化物非贵金属电催化剂可以通过经济简便的方法制备，具有增强的本征活性以及长期稳定性和耐久性，这可能是能量转换和存储应用的新候选材料。
