Nest-like Ag-doped NiMoO4/NF with rich oxygen vacancies as robust catalysts for highly efficient oxygen evolution

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 118; pp. 70 - 77
• Main Authors: Wang, Jianzhi, Luo, Yu, Xu, Tong, Guo, Ziyi, Chen, Guopeng, Ren, Yuchen, Xue, Yanan, Cai, Ning, Li, Hui, Yu, Faquan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.02.2023; 한국공업화학회
• Subjects: Electrocatalysis; NiMoO4; OER; Oxygen vacancy; Silver doping; 화학공학; Electrocatalysis; NiMoO4; OER; Silver doping; Oxygen vacancy
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2022.10.046

In the first step, the Ag nanoparticles doped Ni(OH)2 nanoflower arrays were directly in situ grown on the NF (Ag-Ni(OH)2/NF) by hydrothermal method. In the second step, the Ag doped NiMo LDH nanorod arrays were directly grow on the NF during the hydrothermal stage with the pyrolysis of was immersed into a solution mixture of Na2MoO4 and urea, which resulted in the precipitation of NiMo LDH/Ag/NF. In the third step, the as-prepared NiMo LDH/Ag/NF was completely converted into NiCo2O4/Ag/NF at elevated temperature in a tube furnace. [Display omitted] •Crossed nanorod with high specific surface area and 1D properties was synthesized.•NiMoO4/Ag/NF exhibits high OER activity and low Tafel slope.•The catalytic performance is improved by annealing to produce a rich oxygen gap. The development of low-cost and highly efficient electrocatalysts for oxygen evolution reaction (OER) with good conductivity, high specific surface area and abundant oxygen vacancies is of great significance for the future renewable energy conversion and storage system. Herein, Ag doped NiMoO4 materials on the Ni foam (NiMoO4/Ag/NF) with rich oxygen vacancies were successfully prepared by hydrothermal strategy and layer by layer assembly method. The Ag ions are doped in-situ to promote electron transfer and compensate for the poor conductivity of metal oxides. The suitable air annealing treatment is used to create rich oxygen vacancies. The high specific surface area and one-dimensional characteristics of the cross mesoporous nanorod skeleton are responsible for the increased exposure of active centers and the rapid charge transfer behavior. The NiMoO4/Ag/NF exhibits high activity for OER in alkaline solution (an overpotential of 275 mV at the current density of 20 mA cm−2) and low Tafel slope (53.67 mV dec−1), and a satisfying durability in 1.0 M KOH. This study provides an effective method for the preparation of Ag doped one-dimensional nanomaterials with excellent OER catalytic performance and electrochemical stability.