Lattice interconversion of 1D ferrocene-based perovskite induced by solvent molecules for selective photocatalytic toluene oxidation†

Abstract

Metal halide perovskites (MHPs) have attracted enormous attention for potential applications in the fields of optoelectronics and photocatalysis due to their excellent optoelectronic characteristics, such as broad light absorption range, high charge mobility and long carrier diffusion length. However, using MHPs as photocatalysts for photocatalytic toluene oxidation is rare, and the underlying mechanisms affecting toluene oxidation are still unclear. In this study, we constructed two novel one dimensional (1D) ferrocene-based perovskite catalysts, (C₁₃H₁₇FeNH)PbI₃ and (C₁₃H₁₇FeNH)PbI₃·DEF, of which (C₁₃H₁₇FeNH)PbI₃ can photocatalyze the oxidation of toluene to benzaldehyde effectively. It is interesting that the crystal lattices of (C₁₃H₁₇FeNH)PbI₃ and (C₁₃H₁₇FeNH)PbI₃·DEF can be converted to each other through the gain and loss of solvent molecules, which not only regulates the electronic band structure but also increases the separation efficiency of the photogenerated carriers. These results were confirmed by steady-state photoluminescence (PL) and time-resolved photoluminescence (TRPL) spectra, transient photocurrent response measurements and density functional theory (DFT) calculations. In addition, the lower exciton binding energy (43.2 meV) of (C₁₃H₁₇FeNH)PbI₃ further demonstrated its effective carrier separation efficiency. Furthermore, the selective adsorption of (C₁₃H₁₇FeNH)PbI₃ on toluene and benzaldehyde provided a prerequisite for the efficient selective oxidation of toluene. Finally, (C₁₃H₁₇FeNH)PbI₃ exhibited excellent catalytic activity for the photocatalytic oxidation of toluene to benzaldehyde with a conversion of 28.5% and selectivity (95.3%) towards benzaldehyde.