Synergistic Effect of TP-Ru Complex with Optimized Ru-NP–Loaded Exfoliated g-C₃N₄ for Photocatalytic Green Hydrogen Production

Engineering semiconductors with sensitizers and metals is a recognized strategy for enhancing solar-driven photocatalytic hydrogen production. This study delves into the synergistic impact of utilizing exfoliated g-C3N4 (EC3N4) loaded with ruthenium metal (Ru) and sensitized with a triphenylphosphine ruthenium (TP-Ru) complex to elevate solar-driven H2 evolution. By altering the morphology of g-C3N4 to exfoliate nanosheets, a 1.30-fold increase in H2 production was achieved, attributed to defect formation, facilitating higher charge separation efficiency. Bimetallic Ru and TP-Ru–based cocatalysts exhibit distinct photocatalytic efficiencies, functioning as polymer sensitizers and charge-trapping agents, respectively. Sensitizing EC3N4 with the TP-Ru complex resulted in enhanced visible light absorbance, leading to a significantly higher H2 production. Notably, the performance of Ru was 1.88-fold higher than that of the TP-Ru complex, owing to the efficient separation of charge carriers by Ru. The highest H2 production of 2562.5 μmol g–1 h–1 was achieved when the bimetallic Ru/TP-Ru was attached to EC3N4, surpassing production with 3% Ru/EC3N4, 3% TP-Ru/EC3N4, EC3N4, and g-C3N4 samples by factors of 1.62, 3.04, 38.68, and 48.81, respectively. The optimized Ru/TP-Ru/EC3N4 composite also reveals a quantum yield of 3.745% with continuous hydrogen production in multiple cycles. Ru effectively traps electrons, while the TP-Ru complex maximizes the light absorbance efficiency of g-C3N4 in addition to charge separation. This synergistic interplay of the TP-Ru complex with Ru enhances the hydrogen production efficiency of the EC3N4 nanotexture under solar energy. This innovative approach presents a promising pathway for constructing highly efficient composites for visible light–driven H2 evolution and holds potential for various solar energy applications.