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

Transition-metal phosphides have been demonstrated as cocatalysts with great promise for photocatalytic H₂ production materials, but the insurmountable issue remains maintaining outstanding stability while achieving high photocatalytic efficiency. Herein, the rhodium phosphide (RhP_x) nanospecies as cocatalyst is firmly mounted on graphitic carbon nitride (g-C₃N₄) nanosheets to realize the improved activity and stability for photocatalytic H₂ production. The maximum H₂ production rate over RhP_x/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, RhP_x/g-C₃N₄ can maintain consistently stable H₂ production when enduring over 25 cyclic reactions with a total of 100 h. The deep insight into the modification effect of RhP_x nanospecies reveals that it dramatically facilitates migration and separation of photoinduced electron-hole pairs and heightens interaction at the heterointerfaces between RhP_x 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.