Dynamic Interaction between Methylammonium Lead Iodide and TiO2 Nanocrystals Leads to Enhanced Photocatalytic H2 Evolution from HI Splitting

Organic–inorganic hybrid perovskites have been extensively investigated for solar-to-electricity transformation because of their excellent optoelectronic properties. However, these materials have been rarely pursued as photocatalysts for solar-to-fuel conversion because of their intolerance to water and lack of efficient strategies to promote charge transportation in the nanoscale domain. Herein, Pt/TiO 2 nanoparticles, which act as temporary reservoirs for accommodating methylammonium lead iodide (MAPbI 3 ), were hybridized with MAPbI 3, creating dynamically existing electron-transporting channels between the two components. As a consequence, the charge transportation efficiency for MAPbI 3 nanoparticles was drastically enhanced and the rate of photocatalytic hydrogen evolution from HI splitting was increased by ca. 89 times compared with that of Pt/MAPbI 3 . An apparent quantum efficiency of ca. 70% for H 2 evolution at 420 nm and a solar-to-chemical conversion efficiency of ca. 0.86% were obtained.