Temperature-Induced Lattice Distortion in ZnCo<sub>2</sub>O<sub>4</sub> for Improving Electrocatalytic Oxygen Evolution Reaction
Ming Ya, Yaowen Wang, Jianghao Wang, Guichen Gao, Xu Zhao, Yanhua Wei, Zhibin Geng, Guangshe Li, Liping Li
Abstract
Spinel oxides exhibit considerable potential as electrocatalysts for the oxygen evolution reaction (OER) owing to their diverse surficial composition and electronic structure. Engineering the spin state of metal ions has been acknowledged as an effective approach to improving OER activity. However, comprehensively understanding the intricate connection between the structure and activity still poses challenges. In this study, we present a temperature-induced lattice distortion strategy to manipulate the electronic structure of spinel ZnCo 2 O 4, resulting in remarkable performance toward OER. Experimental findings demonstrate that calcination temperature can precisely control the distortion of the CoO 6 octahedra and thus manipulate the spin state of Co 3+ ions. Magnetic analysis reveals that ZnCo 2 O 4 calcined at 300 °C consists of Co 3+ ions with 64.4% in high-spin and 35.6% in low-spin states, possessing a favorable spin configuration and thus exhibiting optimal OER activity. We believe that the implementation of this strategy can provide valuable insights for developing advanced spinel oxide electrocatalysts based on spin-state engineering.