Comparison of carrier dynamic behavior and photocatalytic molecular oxygen activation of optimized MAPbX3 (X = I, Br)

Abstract

Abstract Understanding carrier dynamic behavior including carrier lifetime and concentration, electrochemical behavior and band structure of the MAPbX3 (X = I, Br) with high crystal quality are important for improving photocatalytic applications. Herein, a facile isopropanol-assisted solvothermal strategy was demonstrated for highly yielding synthesis MAPbX3 (X = I, Br) cubic microcrystals with high crystallinity for degrading water insoluble dyes in an organic solvent system. Supported by time-dependent morphology evolution experimental evidence, a high temperature gradient inside the solution leads to natural convection which can induce the screw dislocation in microcrystals. The XRD, IR, steady-state photoluminescence (PL) spectra, fluorescence lifetimes UV–vis spectra and electrochemical tests were investigated to found a direct correlation between crystal quality (crystallinity and defects) and optical properties (PL intensity and bandgap). Importantly, MAPbBr3 displayed almost an order of magnitude more efficient photocatalytic degradation of malachite green (MG) dye in isopropanol solvent relative to those of MAPbI3, which was ascribed to good stability and superior photoinduced electron transfer for molecular oxygen activation.