Stable perovskite photocathodes for efficient hydrogen evolution in acidic and basic conditions

Organolead halide perovskite photocathodes have shown great potential for photoelectrochemical hydrogen evolution due to their excellent solar-to-hydrogen conversion efficiency. However, the poor stability of perovskite in the aqueous environment and the low HER performance of the catalyst in alkaline conditions have impeded their practical application. Herein, highly efficient, and stable polymer-integrated perovskite photocathodes are fabricated and coupled with Au-Pt-Ni bimetallic catalyst that has ultralow overpotential for HER in both acidic and alkaline conditions. The polymer-integrated photocathode has a high HER photocurrent density (& SIM;-20 mA cm-2), high onset potential (& SIM;0.95 V), and HC-STH (half-cell solar to hydrogen conversion efficiency) of 10.11%. The polymer-integrated perovskite photocathodes show stability values of T80 & SIM; 70 h (in H2SO4) and T80 & SIM; 78 h (in KOH), greatly improving the reported lifetime of such devices. Catalyst design with polymer additive engineering is used to develop highly efficient and stable perovskite-based photocathodes for hydrogen evolution by water splitting.