Bifunctional Cu3P Decorated g-C3N4 Nanosheets as a Highly Active and Robust Visible-Light Photocatalyst for H2 Production

The rational design of sustainable noble-metal-free heterojunctions remains a key challenge for highly efficient and durable photocatalytic H 2 production. In this study, it was revealed that the robust copper phosphide (Cu 3 P) nanoparticles may serve as a cocatalyst and a p-type semiconductor at low (1.5 wt %) and high (10 wt %) loading contents, respectively. Both Cu 3 P cocatalyst and semiconductor could evidently boost visible-light-driven photocatalytic H 2 production over graphitic carbon nitride (g-C 3 N 4 ) nanosheets. Comparably speaking, the heterojunction effects between p-type Cu 3 P and n-type g-C 3 N 4 are speculated to play a more prominent role in dramatically boosting photocatalytic H 2 production than the electron-sink roles of surface Cu 3 P cocatalysts. Impressively, among all the as-fabricated photocatalysts, high quality 10 wt % g-C 3 N 4 –Cu 3 P could achieve the highest photocatalytic H 2 -production rate of 159.41 μmol g –1 h –1, which is approximately 1014 times higher than that of pristine g-C 3 N 4 . In cycling experiments, g-C 3 N 4 –10 wt % Cu 3 P exhibited an acceptable photostability. More importantly, it was further demonstrated that earth-abundant dual-functional Cu 3 P nanoparticles could markedly facilitate the separation of electron–hole pairs and H 2 -evolution kinetics, thus achieving distinctly boosted photocatalytic H 2 generation. This work will provide new insights into the rational design of environmentally friendly g-C 3 N 4 -based hybrid nanoheterojunctions for visible-light-responsive photocatalytic H 2 generation through loading noble-metal-free bifunctional cocatalysts on semiconductors.