One-step direct construction of S-scheme BaTi2O5/g-C3N4 heterojunction for enhanced photocatalytic hydrogen evolution

Heterojunction photocatalysis has been widely studied as a means of efficiently converting solar energy to chemicals. However, the major challenge in developing high-performing heterojunction photocatalytic systems lies in achieving efficient transfer of electrons between the components. Herein, a novel S-scheme heterojunction photocatalyst was developed by combining BaTi₂O5 nanorods with g-C₃N₄ lamellae. The preferential deposition of Pt nanoparticles as cocatalyst via the one-step impregnation-reduction method on g-C₃N₄ nanosheets with enhanced interfacial contact and strong electronic interaction has been proved essential for the photocatalytic performance. The developed Pti_mp/20BaTi₂O₅/g-C₃N₄ photocatalyst delivers the optimal hydrogen production rate of 2587 µmol g⁻¹ h⁻¹ with high stability after cycles. Photoelectrochemical analysis and theoretical calculation suggest that the formation of BaTi₂O₅/g-C₃N₄ heterojunction results in the staggered band alignment and improved charge carrier dynamics. This work highlights the importance and feasibility of promoting photocatalysis by a new S-scheme heterojunction with viable cocatalysts.