Enhanced photocatalytic water oxidation driven by nitrogen sites in a polymer framework

Abstract Developing efficient and durable photocatalytic systems remains a formidable challenge, especially in seawater which is more attractive for practical applications. Herein, we report a polymer framework (PFN) featuring nitrogen (N) sites as a versatile host to anchor nickel (Ni) hydroxide (NH) via Ni‐N coordination and cadmium sulfide (CdS). The resulting CdS/NH@PFN delivers an oxygen evolution rate of 180.6 μmol h −1 cm −2 in photocatalytic water oxidation, outperforming the PFN‐free system by four orders of magnitude. Remarkably, CdS/NH@PFN confers exceptional resistance to seawater corrosion, enabling stable seawater splitting for over 100 h, and demonstrates perfect linear scalability up to a 1 m 2 array without efficiency loss. We identify that Ni‐N coordination drives a synergistic mechanism, simultaneously accelerating interfacial charge transfer and promoting water activation on catalytic active sites, thus yielding the efficient and durable photocatalytic oxidation of freshwater and seawater in CdS/NH@PFN. These results offer a versatile strategy for fabricating robust photocatalytic systems.