Expediting H2 Evolution over MAPbI3 with a Nonnoble Metal Cocatalyst Mo2C under Visible Light

Halide perovskites have been emerging as promising photocatalytic materials for H 2 evolution from water due to their outstanding photoelectric properties. However, the lack of proper surface reactive sites greatly hinders the photocatalytic potential of these fascinating compounds. Here, Mo 2 C nanoparticles have been anchored onto methylammonium lead iodide (MAPbI 3 ) as a nonnoble metal cocatalyst to promote H 2 evolution reactions. The Mo 2 C nanoparticles have opposite zeta potential with MAPbI 3 thereby electrostatically assembled onto the MAPbI 3 surface, i.e., Mo 2 C@MAPbI 3 . Our results show that the anchored Mo 2 C nanoparticles have a strong interplay with MAPbI 3 substrate so that photogenerated electrons of MAPbI 3 can be rapidly separated and transferred into Mo 2 C for further H 2 evolution reactions. Under optimal conditions, Mo 2 C@MAPbI 3 delivers exceptionally high photocatalytic performance for visible light-driven H 2 evolution that clearly outperforms pristine MAPbI 3 and Pt-deposited MAPbI 3 . An apparent quantum efficiency as high as 12.65% at 600 ± 40   nm has been attained for H 2 evolution, surpassing most of the MAPbI 3 -based photocatalyst reported. These results signify the usefulness and applicability of Mo 2 C as a new nonnoble metal-based cocatalyst in solar water splitting.