Band Modulation and Interfacial Engineering to Generate Efficient Visible-Light-Induced Bifunctional Photocatalysts

To construct photocatalysts with matched band alignments and intimate interfaces is crucial but challenging for photocatalysis. Herein, we for the first time report a strategy for band modulation and interface engineering to generate an efficient bifunctional photocatalyst. By interstitially doping P into g-C3N4 and quantizing CoP, the fabricated CoPQD/P-g-C3N4 hybrid possesses a tailed heterojunction with intimate interfaces via the in situ generated interfacial Co–P bonds. CoPQD/P-g-C3N4 as a noble-metal free bifunctional photocatalyst displays excellent photocatalytic redox efficiency for both hydrogen generation and pollutant degradation under visible light. Combining experimental with theoretical investigation, it is manifested that the matched band alignments of the CoPQD/P-g-C3N4 heterojunction and the intimate interface via the Co–P interfacial bonds facilitate the photogenerated charge separation/transfer and meanwhile guarantee long-term stability. This work addresses the importance of band alignments and the heterojunction interface and presents an effective strategy for band modulation and interface engineering of noble-metal free photocatalysts.