In-situ synthesis of PdAg/g-C3N4 composite photocatalyst for highly efficient photocatalytic H2 generation under visible light irradiation

Novel PdAg bimetallic alloy nanoparticle modified graphitic carbon nitride (g-C3N4) nanosheet was designed and prepared by an in situ chemical reduction procedure. By optimizing the loading content of the PdAg alloy NPs, the PdAg/g-C3N4 composite photocatalyst showed a champion photocatalytic hydrogen generation rate of 3.43 mmol h−1 g−1, and the apparent quantum yield (AQY) was determined to be 8.43% at 420 nm. Moreover, the photoluminescence and photoelectrochemical experimental results suggest that a higher separation efficiency of photo-induced charge carriers (e- and h+) was obtained after loading PdAg alloy NPs on g-C3N4. The experimental outcomes indicate that there is a synergistic effect formed between PdAg and g-C3N4, which could significantly promote the charge transfer photo-induced charge carriers in the hybrid sample. A reasonable catalytic mechanism for the enhanced photocatalytic performance of the composite photocatalyst was proposed and verified by TRPL measurement, which could be taken as a guidance for the development of novel high performance catalytic system.