Graphdiyne supported rare earth tungstate forms 2D/2D heterojunction and promotes photocatalytic hydrogen production through synergistic interaction

Abstract

The high carrier recombination rate of photocatalysts remains a critical challenge for solar-driven hydrogen production. To address this issue, we propose a dual strategy combining morphology regulation and heterojunction construction. Here, 2D material graphdiyne (GDY) was combined with 2D La2(WO4)3 (LW) nanosheets to form a GDY/ LW heterostructure, achieving a remarkable photocatalytic H2 evolution rate under visible light. Through SEM and BET characterization, it is evident that the hierarchical architecture provides an enlarged specific surface area with abundant active sites. The charge transfer mechanism was systematically elucidated through integrated experimental and theoretical approaches: UV–vis DRS and Mott-Schottky analyses established a type-I band alignment between LW and GDY. In-situ XPS and work function analyses unequivocally demonstrated the formation of an interfacial electric field, which drives the migration of photogenerated electrons from LW to GDY. This directional charge separation effectively suppressed carrier recombination, as evidenced by significantly reduced recombination rates in PL and TRPL spectra. The synergistic effects of morphology optimization and heterojunction engineering provide a novel paradigm for reactivating wide-bandgap semiconductors and advancing carbon-based photocatalytic systems.