Antisolvent solvothermal synthesis of MAPbBr3 nanocrystals for efficient solar photodecomposition of methyl orange.

Exploring high performance photocatalysts is of great importance to relieve the environment pollution issues. In this paper, we introduce a facile antisolvent solvothermal method to synthesize methylammonium lead tribromide perovskite (MAPbBr3) nanocrystals and successfully employ them as efficient photocatalysts. Compared to the room temperature synthesized MAPbBr3 (RT-MAPbBr3), the antisolvent solvothermal synthesized MAPbBr3 (AS-MAPbBr3) has multiple outstanding properties, such as improved crystallinity with lower grain boundary density, enhanced light absorption in visible range, suitable band gap of 2.31 eV and extended photoluminescence (PL) lifetime as long as 2627.82 ns. By taking advantages of the above merits, the AS-MAPbBr3 exhibits efficient photocatalytic performance by decomposition of methyl orange under solar light. A high apparent rate constant of 101.2 × 10-3 is achieved along with excellent cyclability, which significantly outperforms the RT-MAPbBr3 (56.0 × 10-3) and P25 (16.5 × 10-3). The underlying mechanism for MO photocatalytic degradation is deeply explored and proposed. Our present study suggests that the antisolvent solvothermal method can be a promising method to synthesize perovskite nanocrystals, and might also provide some insights in developing a series of high performance perovskite based photocatalysts.