Combined Exsolution and Electrodeposition Strategy for Enhancing Electrocatalytic Activity of Ti-Based Perovskite Oxides in Oxygen and Hydrogen Evolution Reactions

Abstract

The significant interest in perovskite oxides stems from their compositional and structural flexibility, particularly in the field of electrochemistry. In this study, the double E strategy (exsolution and electrodeposition strategies) is successfully devised for synthesizing perovskite-based bifunctional electrocatalysts, enabling simultaneous OER and HER applications with exceptional catalytic performance. The synthesized R-LCTFe/Ni catalyst exhibits outstanding electrocatalytic activity, delivering low overpotentials of 349 and 309 mV at 10 mA cm⁻² for OER and HER, respectively, indicating substantial improvements in the inherent electrocatalytic activity. Moreover, the impressive stability of R-LCTFe/Ni under alkaline conditions underscores its potential for practical water electrolysis applications. The superior bifunctional electrocatalytic performance can be attributed to the reduced charge transfer resistance and the synergistic cooperation between exsolved Fe nanoparticles and electrodeposited Ni compounds. The successful development of the R-LCTFe/Co catalyst further confirms the transferability of the double E strategy. Compared to R-LCTFe/Ni, the overpotential of R-LCTFe/Co is 58 mV higher for OER, yet 48 mV lower for HER at a current density of 10 mA cm⁻². This study provides an efficient and promising approach for the fabrication of highly active perovskite-based electrocatalysts, contributing valuable insights into the design of bifunctional electrocatalysts for OER and HER.