The Role of Surface Termination in Halide Perovskite for Efficient Photocatalytic Synthesis.

: Halide perovskites have received extensive attention in the field of photocatalysis owing to their excellent optoelectronic properties. However, the semiconductor properties of halide perovskite surface and the influences on the photocatalytic performances have not been systematically clarified. Here we employ the conversion of triose (e.g. 1,3-dihydroxyacetone (DHA)) as a model reaction to explore the surface termination of MAPbI 3 . By rational design of the surface termination for MAPbI 3 , we substantially improve the production rate of butyl lactate to 7719 μg/g cat./h under visible light illumination. It reveals that MAI-terminated MAPbI 3 surface governs the photocatalytic performance. Specially, MAI-terminated surface is susceptible to iodide oxidation, which thus promotes the exposure of Pb(II) as active sites for this photocatalysis process. Moreover, MAI-termination induces p-doping effect near the surface for MAPbI 3 , which facilitates the carrier transport and thus photosynthesis. The understanding of the surface termination in MAPbI 3 photocatalyst suggests a new avenue to engineer halide perovskite semiconductor materials for future photocatalysis.