Porphyrin-Based Conjugated Polyelectrolytes for Efficient Photocatalytic Hydrogen Evolution

Photocatalytic hydrogen evolution from water has recently drawn tremendous attention and stimulated extensive efforts in the design of high-performance photocatalysts. Here, we designed a series of porphyrin-based conjugated polyelectrolytes (CPEs) with different coordinated metals for the efficient photocatalytic hydrogen evolution. The polar side chains in these CPEs allow the formation of nanoscale aggregates in water for photocatalysis. The central metals (Ni, Cu, and Pt) incorporated into the porphyrin units greatly alter the electronic properties and photocatalytic performance of CPEs, marking them as distinct from metal-free CPEs. The Pt atom incorporated into CPEs efficiently induces exciton generation, reduces charge transfer resistance, and enhances the interaction between the CPEs and the co-catalysts and water. Consequently, PPF-Pt-Br enables efficient photocatalytic hydrogen evolution of up to 5.39 mmol g–1 h–1 without the assistance of co-catalysts and 37.9 mmol g–1 h–1 with co-catalysts, which is much higher than the capacity of other CPEs. This study provides a novel strategy to improve photocatalytic efficiency by optimizing the chemical structure of conjugated polymers.