An enhanced electrocatalytic oxygen evolution reaction by the photothermal effect and its induced micro-electric field

Abstract

Promoting better thermodynamics and kinetics of electrocatalysts is key to achieving an efficient electrocatalytic oxygen evolution reaction (OER). Utilizing the photothermal effect and micro-electric field of electrocatalysts is a promising approach to promote the sluggish OER. Herein, to reveal the relationship of the photothermal effect and its induced micro-electric field with OER performance, NiS_x coupled NiFe(OH)_y on nickel foam (NiS_x@NiFe(OH)_y/NF) is synthesized and subjected to the OER under near-infrared (NIR) light. Owing to the photothermal effect and its induced micro-electric field, the OER performance of NiS_x@NiFe(OH)_y/NF is significantly enhanced. Compared with no NIR light irradiation, the overpotential at 50 mA cm⁻² and the Tafel slope of NiS_x@NiFe(OH)_y/NF under NIR light irradiation were 234.1 mV and 38.0 mV dec⁻¹, which were lower by 12.4 mV and 7.1 mV dec⁻¹, and it exhibited stable operation at 1.6 V vs. RHE for 8 h with 99% activity maintained. This work presents a novel inspiration to understand the photothermal effect-enhanced electrocatalytic OER.