Engineering water-stable metal halide perovskite/MOF-808 heterojunction through mechanochemical method: S-scheme photocatalytic system for multifunctional applications

Enhancing the stability of metal halide perovskite (MHP) in a water-contained reaction system is the key point for their practical photocatalysis applications. Here, we focused on MOF-808 as a host to prevent the degradation of pre-synthesized CsPbBr3 nanoparticles. The CsPbBr3/MOF-808 nanocomposite was prepared through a solvent-free mechanochemical method. The perovskite/MOF heterojunction maintains the integrity of MOFs while enhancing the stability of MHP by embedding in MOF-808. The prepared MHP/MOF composite provides an impressive photocatalytic Cr(VI) reduction and antibiotic removal by the synergistic activity of the two composite constituents. The result of 92% toward photocatalytic Cr(VI) reduction and 97% antibiotic degradation in an aqueous system was attained within 120 min over CsPbBr3/MOF-808. Moreover, under acidic conditions, the catalyst kept its stability after three runs of reaction. Our study expands a simple synthesis method for MHP/MOF water-stable composites, which could be valuable for the development of MHP-based heterojunctions.