Methylamine lead bromide perovskite/protonated graphitic carbon nitride nanocomposites: interfacial charge carrier dynamics and photocatalysis

We demonstrate the decoration of methylamine lead bromide (MAPbBr 3 , MA: CH 3 NH 3 + ) perovskite nanoparticles on protonated graphitic carbon nitride (p-g-C 3 N 4 ) sheets to form nanocomposites (NCs) for the first time. The intrinsic type II band structure of MAPbBr 3 /p-g-C 3 N 4 NCs resulted in significant charge separation properties, which were greatly beneficial for related applications in photoelectric conversion. The interfacial charge transfer behavior of MAPbBr 3 /p-g-C 3 N 4 NCs was analyzed via time-resolved photoluminescence (TRPL) spectroscopy and singular-value decomposition global fitting (SVD-GF), which revealed that photoexcited electrons in the conduction band (CB) and shallow-trap (ST) states of MAPbBr 3 could be transferred into the CB of g-C 3 N 4 . The fitting results for TRPL traces indicated that the control of the related compositions could modulate the interfacial charge carrier dynamics of MAPbBr 3 /g-C 3 N 4 NCs. An increase in the charge transfer rate constant ( k et ) for MAPbBr 3 /g-C 3 N 4 NCs was discovered when the constituent ratio of p-g-C 3 N 4 was enhanced. Furthermore, we utilized MAPbBr 3 /p-g-C 3 N 4 NCs as a photocatalyst to carry out the photocatalytic reduction of p -nitrophenol (PNP) under visible-light irradiation. A significant photoreduction rate ( k PNP ) of PNP was observed in the photocatalytic reaction, which indicated the great potential of MAPbBr 3 /p-g-C 3 N 4 NCs to convert solar energy into chemical energy. In particular, the present investigation opens a new field for organolead bromide perovskites in applications in photocatalysis, as well as related photoelectric conversion.