Halide Perovskite Photocatalysts in Action: Integrating Photostability, Solvent Robustness, and Surface Charge Management

Metal halide perovskites (MHPs) have rapidly expanded beyond their photovoltaic origins to emerge as powerful colloidal photocatalysts, yet their catalytic deployment is still hindered by three persistent limitations: light-induced instability, rapid degradation in polar media, and poor charge utilization at the interfaces. This spotlight critically re-examines these challenges and outlines molecular-level strategies, via ligand engineering and tailored charge acceptors, that directly confront them. We first demonstrate how illumination alters the phase and morphology of MHPs and assess the strategies that can stabilize their photoactive structures. We then dissect the complex interactions between MHPs and polar reaction environments, placing special focus on water. Achieving true water stability is noted to be a crucial breakthrough in MHP photocatalysis, allowing water to serve not just as a solvent but also as a reactant, charge scavenger, and catalytic medium. Moreover, recognizing that catalytic efficiency ultimately hinges on charge management, we dedicate a section to how molecular acceptors, extraction mechanisms, and interfacial crowding dictate carrier utilization. Taken together, these insights establish an integrated design blueprint in which photostability, reaction media compatibility, and charge dynamics operate as inseparable levers. By aligning these parameters, MHP-based photocatalysis can advance from fragile proof-of-concept demonstrations to robust systems capable of supporting scalable, industrially relevant chemical transformations.