Violet phosphorus quantum dots regulate exciton dissociation and radial charge flow in crystalline g-C₃N₄ nanorods for boosting photocatalytic H₂ evolution

The photocatalytic performance of exciton-rich g-C₃N₄ is hindered due to its strong electron-hole Coulomb interactions and disordered charge dynamic behavior. Herein, oriented photoelectrons transfer in crystalline g-C₃N₄ nanorods (CCNR) is significantly boosted by marginal encapsulation with violet phosphorus quantum dots (VPQDs), forming 0D/1D VPQDs/CCNR heterostructure with lateral P–N bonds. Experimental and theoretical results revealed that the accelerated exciton dissociation was attributed to the strong built-in electric field between CCNR and VPQDs, which reduced the electrostatic potential within each π-conjugated plane, thus providing a driving force for exciton dissociation. A subsequent radial charge flow from CCNR to the active sites on the VPQDs improved the photocatalytic performance of the material. The optimized VPQDs/CCNR exhibited an excellent photocatalytic H₂ evolution rate of 7084.98 µmol g^-1h⁻¹ with an apparent quantum yield of 16.1 % at 400 nm. This study offers in-depth insights into regulating exciton dissociation and oriented charge flow in CCNR.