Photocatalytic Overall Water Splitting with a Solar-to-Hydrogen Conversion Efficiency Exceeding 2 % through Halide Perovskite.

Photocatalytic water splitting using semiconductors is a promising approach for converting solar energy to clean energy. However, challenges such as sluggish water oxidation kinetics and limited light absorption of photocatalyst cause low solar-to-hydrogen conversion efficiency (STH). Herein, we develop a photocatalytic overall water splitting system using I /I as the shuttle redox couple to bridge the H-producing half-reaction with the O-producing half-reaction. The system uses the halide perovskite of benzylammonium lead iodide (PMAPbI, PMA=CHCHNH) loaded with MoS (PMAPbI/MoS) as the H evolution photocatalyst, and the RuO-loaded WO (WO/RuO) as the O evolution photocatalyst, achieving a H/O production in stoichiometric ratio with an excellent STH of 2.07 %. This work provides a detour route for photocatalytic water splitting with the help of I /I shuttle redox couple in the halide perovskite HI splitting system and enlightens one to integrate and utilize multi catalytic strategies for solar-driven water splitting.