Invigorating active sites for amorphous/crystalline heterophased co-based oxyhydroxide/tungstate toward enhanced electrocatalytic oxygen evolution: Trimetallic codoping-achieved synergistic regulation

Abstract

Designing high-efficiency multimetal-based catalysts for oxygen evolution reaction at low overpotential is a grand challenge in alkaline water splitting due to the elusive synergistic effect between metal atoms. Blind pursuit of polymetallic miscibility cannot linearly enhance catalytic activity; instead, it incurs increased costs. Herein, we reported a facile trimetallic (Cu, Fe and La) codoping approach to tailor the electronic structure of Co-based oxyhydroxide/tungstate for boosting OER reaction. It was found that a better synergistic effect with Co can be exhibited only when Cu, Fe and La were coexisted in the catalyst. By virtue of this, the catalyst developed numerous oxygen vacancies, enhancing favorability for OER reaction and demonstrating high intrinsic activity. Systematic experiments additionally verified its improved reaction kinetics and optimized adsorption to intermediates. Ultimately, the prepared CoCuFeLa significantly reduced overpotential, decreasing by a minimum of 50 mV compared to monometallic doping. The alkaline electrolyzer based on the CoCuFeLa anode exhibited a low cell voltage of 1.53 V for water splitting. Remarkably, it experienced a substantial attenuation of 3.54 % after 150 h of continuous operation, attributing to the changes in the surface structure of the catalyst. This work provides a viable pathway for improving catalytic activity through multimetallic codoping, further promoting the design of more valuable multimetallic catalysts for hydrogen market.