Zero- and One-Dimensional Lead-Free Perovskites for Photoelectrochemical Applications

The development of 100% lead-free perovskite materials for photoelectrochemical applications is a hot topic in the current research scenario. Herein, by varying the preparation strategy, we have synthesized two distinct lead-free manganese halide perovskite nanocrystals (NCs), CsMnCl₃(H₂O)₂ (1D-CMC₃H) and Cs₂MnCl₄(H₂O)₂ (0D-C₂MC₄H), by simple ultrasonication/crystallization and a modified ligand-assisted reprecipitation (LARP) approach (room temperature synthesis), respectively. For the first time, a polar solvent methanol was used instead of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) for the synthesis of perovskite NCs. These two manganese halide perovskites exhibit unique morphology-dependent photoluminescence properties. The photoelectrochemical properties of these two Mn-halide-based perovskite NCs were evaluated through electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV). The as-prepared one-dimensional (1D) and zero-dimensional (0D) Mn-halide perovskites exhibit more effectual dissociation of photogenerated electron-hole pairs as well as the presence of more rapid interfacial charge transfer on the photoelectrodes under light irradiation. Further improvement in the photoelectrochemical behavior of the 1D-CMC₃H and 0D-C₂MC₄H perovskite photoelectrodes is achieved with eco-friendly ZnO. The overall photoelectrochemical performances of Mn-halide perovskites with ZnO afforded excellent light-harvesting and charge carrier properties.