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

Understanding carrier dynamic behavior including carrier lifetime and concentration, electrochemical behavior and band structure of the MAPbX 3 (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 MAPbX 3 (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, MAPbBr 3 displayed almost an order of magnitude more efficient photocatalytic degradation of malachite green (MG) dye in isopropanol solvent relative to those of MAPbI 3 , which was ascribed to good stability and superior photoinduced electron transfer for molecular oxygen activation.