Self-gating enhanced carrier transfer in semiconductor electrocatalyst verified in microdevice

Semiconductor electrocatalysis with weak conductivity can accumulate extremely high carriers at semiconductor-electrolyte interface by self-gating effect, which strongly promotes electrocatalytic efficiency. The correlation between semiconductor carrier mobility and electrocatalysis performance is still unclear. Herein atomic-thin transition metal dichalcogenides based composites have been developed for hydrogen evolution reaction (HER) performed with on-chip microdevices. Electrical and electrochemical measurement of individual flack verified the key role of high carrier mobility for enhanced HER activity. Carrier mobility regulation further demonstrated its high dependence with HER performance under self-gating. Our study provides new insight into the carrier mobility of the semiconductor in the electrocatalysis, paving the way for designing high-performance semiconductor catalysts.