Zhou Zhihao, Lu Zhi, Li Shilin, Li Yiting, Tan Gongliang, Hao Yang, Wang Yu, Huang Yuzhao, Zhang Xuefeng, Li Shuaifang, Chen Chong, Wang Guangxin
School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China.
Luoyang Key Laboratory of High Purity Materials and Sputtering Targets, Henan University of Science and Technology, Luoyang 471003, China.
Nanomaterials (Basel). 2022 Oct 22;12(21):3716. doi: 10.3390/nano12213716.
Oxygen evolution reaction is a key process in hydrogen production from water splitting. The development of non-noble metal electrode materials with high efficiency and low cost has become the key factor for large-scale hydrogen production. Binary NiCo-layered double hydroxide (LDH) has been used as a non-noble metal electrocatalyst for OER, but its overpotential is still large. The microstructure of the catalyst is tuned by doping Mo ions into the NiCo-LDH/NF nanowires to form ternary NiCoMo-LDH/NF nanosheet catalysts for the purpose of enhancing the active sites and reducing the initial overpotential. Only 1.5 V (vs. reversible hydrogen electrode (RHE), ≈270 mV overpotential) is required to achieve a catalytic current density of 10 mA cm and a small Tafel slope of 81.46 mV dec in 1 M KOH solution, which manifests the best performance of NiCo-based catalysts reported up to now. Electrochemical analysis and micro-morphology show that the high catalytic activity of NiCoMo-LDH/NF is attributable to the change of the microstructure. The interconnected nanosheet arrays have the obvious advantages of electrolyte diffusion and ion migration. Thus, the active sites of catalysts are significantly increased, which facilitates the adsorption and desorption of intermediates. We conclude that NiCoMo-LDH/NF is a promising electrode material for its low cost and excellent electrocatalytic properties.
析氧反应是水分解制氢过程中的关键步骤。开发高效低成本的非贵金属电极材料已成为大规模制氢的关键因素。二元镍钴层状双氢氧化物（LDH）已被用作析氧反应的非贵金属电催化剂，但其过电位仍然较大。通过将钼离子掺杂到NiCo-LDH/NF纳米线中以调整催化剂的微观结构，形成三元NiCoMo-LDH/NF纳米片催化剂，目的是增加活性位点并降低初始过电位。在1 M KOH溶液中，仅需1.5 V（相对于可逆氢电极（RHE），过电位约为270 mV）即可实现10 mA cm的催化电流密度和81.46 mV dec的小塔菲尔斜率，这表明了迄今为止报道的镍钴基催化剂的最佳性能。电化学分析和微观形貌表明，NiCoMo-LDH/NF的高催化活性归因于微观结构的变化。相互连接的纳米片阵列具有电解质扩散和离子迁移的明显优势。因此，催化剂的活性位点显著增加，这有利于中间体的吸附和解吸。我们得出结论，NiCoMo-LDH/NF因其低成本和优异的电催化性能而成为一种有前景的电极材料。
