Boosting photocatalytic H₂ evolution through interfacial manipulation on a lotus seedpod shaped Cu₂O/g-C₃N₄ p-n heterojunction

Precisely modulating the interfacial contact of heterojunction photocatalysts and regulating the spatial transfer of photoexcited charge carriers play a significant role in promoting the photocatalytic efficiency. Herein, a novel lotus seedpod shaped Cu₂O/g-C₃N₄ p-n heterojunction composite was fabricated by in situ filling the g-C₃N₄ framework with Cu₂O hollow nanospheres. The obtained Cu₂O/g-C₃N₄ p-n heterojunction presents superior photocatalytic H₂ evolution activity with an optimal production rate of 637.5 μmol g⁻¹ h⁻¹, which is 40 times higher than that of pure g-C₃N₄. Through the combination of characterization and density functional theory (DFT) calculations, the boosted photocatalytic activity of Cu₂O/g-C₃N₄ is attributed to the optimized p-n heterojunction structure with a proper band configuration and suitable heterojunction interface, which can improve the spatial separation of the photoexcited charge carriers and promote the charge transfer efficiency. This investigation is expected to highlight the promising scope of rationally constructing a p-n heterojunction with ideal interfacial contact, and intelligent regulation of the spatial separation of photoexcited charge carriers for photocatalytic water splitting.