Ultrathin Porous Carbon Nitride Anchored with Pt Nanoclusters for Synergistic Enhancement of Hydrogen Production in Alkaline Photocatalytic Polyester Reforming

Photocatalytic reforming (PR) of polyester waste, fueled by renewable sources like solar energy, offers a sustainable method for producing clean H 2 and valuable by‐products under mild conditions. The design of high‐performance photocatalyst plays a pivotal role in determining the efficacy of an alkaline polyester PR system, influencing H 2 generation activity and selectivity. Here, ultrathin porous carbon nitride nanosheets (UP‐CN) loaded with Pt nanoclusters (Pt NCs, average diameter of 1.7 nm) with uniform Pt NCs distribution are introduced. The resulting Pt NCs/UP‐CN catalyst can accelerate charge and mass transfer while providing additional active sites, achieving superior H 2 generation rates of 11.69 mmol g cat −1 h −1 and 2923 mmol g Pt −1 h −1 under AM 1.5 light, which nine times higher than that of Pt nanoparticles‐bulk graphitic carbon nitride composite (1.29 mmol g cat −1 h −1 and 258 mmol g Pt −1 h −1 ) as counterpart. This performance also surpasses that of previously reported carbon nitride‐based and TiO 2 ‐based photocatalysts. Moreover, the density functional theory calculations reveal a significant reduction in the energy barrier for the water dissociation step (H 2 O + * → *H + OH) at the interface between UP‐CN and anchored Pt NCs, showcasing the synergistic effect between Pt NCs and UP‐CN. This catalytic system also exhibits universality across various polyester plastics.