Insight into the Activity and Stability of RhXP Nano-Species Supported on g-C3N4 for Photocatalytic H2 Production

Transition-metal phosphides have been demonstrated as cocatalysts with great promise for photocatalytic H-2 production materials, but the insurmountable issue remains maintaining outstanding stability while achieving high photocatalytic efficiency. Herein, the rhodium phosphide (RhPx) nanospecies as cocatalyst is firmly mounted on graphitic carbon nitride (g-C3N4) nanosheets to realize the improved activity and stability for photocatalytic H-2 production. The maximum H-2 production rate over RhPx/g-C3N4 driven by visible light diplays a 5.6-fold improvement compared with Pt/g-C3N4. Meanwhile, the apparent quantum efficiency of 18.4% is achieved at a fixed wavelength of 420 nm that far exceeds the reported g-C3N4 modified with other single-transition-metal phosphides. Particularly, RhPx/g-C3N4 can maintain consistently stable H-2 production when enduring over 25 cyclic reactions with a total of 100 h. The deep insight into the modification effect of RhPx nanospecies reveals that it dramatically facilitates migration and separation of photoinduced electron-hole pairs and heightens interaction at the heterointerfaces between RhPx nanospecies and g-C3N4 nanosheets. This contribution extends the broad potential application of transition-metal phosphides as cocatalysts in the photocatalytic conversion from solar to hydrogen energy.