Investigating the interfacial properties of halide perovskite/TiO heterostructures for versatile photocatalytic reactions under sunlight.

Heterostructures of metal halide perovskites and TiO are efficient photocatalytic materials owing to the combination of the advantages of each compound, specifically the high absorption coefficients and long charge-carrier lifetimes of perovskites, and efficient photocatalytic activity of TiO. However, chemical reduction of CO using PNC/TiO heterostructures without organic solvents has not been reported yet. Here, we report the first solvent-free reduction of CO using amorphous TiO with embedded colloidal perovskite nanocrystals (PNCs). The combination was obtained by carrying out hydrolysis of titanium butoxide (TBOT) on the PNC surface without high-temperature calcination. We proposed a mechanism involving photoexcited electrons being transferred from PNCs to TBOT, enabling photocatalytic reactions using TiO under visible-light excitation. We demonstrated efficient visible-light-driven photocatalytic reactions at PNC/TiO interfaces, specifically with a CO production rate of 30.43 μmol g h and accelerated degradation of organic pollutants under natural sunlight. Our work has provided a simple path toward both efficient CO reduction and photocatalytic degradation of organic dyes.