Single-atom catalysts supported on two-dimensional tetragonal transition metal chalcogenides for hydrogen and oxygen evolution

Abstract

Single-atom catalysts (SACs) offer maximum metal atom utilization and high catalytic performance. Transition metal atoms on two-dimensional (2D) materials are effective for improving electrocatalytic performance. However, few studies exist on SACs supported on 2D tetragonal transition metal chalcogenides (TMX) for OER and HER. We report a detailed theoretical study using DFT calculations on SACs supported on TMX monolayers, denoted as TM_A@TM_BX. Our findings demonstrate that seven TM_A@TM_BX electrocatalysts surpass IrO₂ (η_OER = 0.56 V), with four TM_A@TM_BX exhibiting a reduced OER overpotential compared to RuO₂ (η_OER = 0.42 V). Additionally, four TM_A@TM_BX exhibit higher HER performance than Pt (111) (η_HER = 0.10 V). We ultimately identified three SACs with high bifunctional HER/OER activity: Co@NiSe, Rh@NiTe, and Co@NiS. This study on TM_A@TM_BX provides insights for enhancing the HER and OER activities of SACs supported on 2D materials, which could have significant implications in clean and renewable energy.