Multi-dimensional collaborations boost lead halide perovskite driven superior and long-period CO₂ photoreduction under liquid-phase H₂O environment

CsPbBr₃ is considered as a promising photocatalyst owning to its excellent photoelectronic characteristics. However, the photocatalytic activity is still unsatisfactory due to its narrow light absorption range, weak electron reduction potential, and poor water-resistance. In this work, a three-dimensional porous melamine foam (MF) supported CsPbBr_3−xI_x was prepared via facile anti-solvent (isopropanol, IPA) and ion doping strategies, which successfully realize efficient photocatalytic CO₂ reduction under liquid-phase H₂O medium. The anti-solvent strategy enables uniform distribution of perovskite crystals on MF surface, which is beneficial to the increase of specific surface area and active sites. The iodine ion (I^-) replacement can enhance light absorption and electron reduction capacity of CsPbBr₃, contributing to the CO₂ photoreduction. Under simulated solar irradiation, powdery CsPbBr₃ exhibits no photocatalytic activity owing to its quick degradation in H₂O medium. Interestingly, MF assisted perovskites presents the enhanced performance, with 195.97 μmol g⁻¹·h⁻¹ of product yield for CsPbBr₂I (IPA), which is 22.0 times higher than that of MF/CsPbBr₃. Moreover, the excellent photothermal recoverable effect and surface hydrophobicity of MF/CsPbBr₂I (IPA) result in a long-period and stable photocatalytic CO₂ reduction with no evident decrease of photocatalytic activity during 42 h.