Amorphous Bimetallic Phosphate–Carbon Precatalyst with Deep Self-Reconstruction toward Efficient Oxygen Evolution Reaction and Zn–Air Batteries

作者：Xinhe Liu, Quanzhou Yin, Chenchen Dai, Guochun Li, Jiabiao Lian, Yan Zhao, Shiliu Yang, Huaming Li · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2021 · DOI：10.1021/acssuschemeng.0c09339 · 被引用次数：35 · 研究领域：Electrocatalysts for Energy Conversion、Advanced battery technologies research、Fuel Cells and Related Materials

Amorphous transition-metal compounds ( a -TMC) have attracted more and more attention due to their high electrocatalytic activity for the oxygen evolution reaction (OER). However, it is still a challenge to in situ synthesize a -TMC-carbon nanocomposites at elevated temperature and figure out the exact advantages of the amorphous structure. Here, an amorphous iron-doped nickel phosphate–carbon hollow nanocomposite ( a -NiFePO-C) has been simply prepared by coprecipitation of metal ions and phytic acid, followed by a controllable annealing process. The results show that a -NiFePO-C can achieve a low overpotential of 268 mV at 10 mA/cm 2 and maintain 91.3% of the initial current density after a 9 h chronoamperometry test in a 1 M KOH solution with low mass loading of 0.1 mg/cm 2 . The excellent performance of a -NiFePO-C is attributed to the low charge-transfer resistance, bulk self-reconstruction, and synergetic oxidation of the bimetallic sites during cyclic voltammetry (CV) activation, resulting in the formation of a highly OER-active Fe(III)-Ni(oxy)hydroxide-carbon nanocomposite. Moreover, the rechargeable Zn–air batteries powered by the a -NiFePO-C + Pt/C electrode can present a lower charging voltage and superior cycle performance than that powered by a commercial RuO 2 + Pt/C electrode.