Stable and efficient Ti3C2 MXene/MAPbI3-HI system for visible-light-driven photocatalytic HI splitting

Photo absorbing perovskites i.e. MAPbI3 have recently been emerging as promising photocatalysts for H2 evolution from HI solution. However, the adverse charge recombination of MAPbI3 at the nanoscale domain hinders its photocatalytic H2 evolution reaction (HER) performance. To address this issue, the metallic Ti3C2 MXene nanosheets is in-situ anchored on MAPbI3 to construct stable and efficient MXene/MAPbI3-HI system for visible-light-driven photocatalytic H2 evolution. The exfoliated MXene is approximate two-layer with the thickness of ∼2.52 nm, and a series of optical/optoelectrochemical characterizations demonstrate that the two layered MXene is capable of rapidly transporting the electrons from MAPbI3 to effectively inhibit the charge recombination and simultaneously providing abundant active sites for H+ reduction and H2 evolution. As a result, the photocatalytic performance of the MXene/MAPbI3 in term of HER rate and stability is greatly promoted, with an extremely high HER rate of 3124 μmol h−1 g−1. This work provides a rational route on the reliable design and synthesis of high-efficiency and stable 2D electron transport/3D light absorber perovskite-based photocatalysts.