The use of photocatalysts to purify wastewater and simultaneously convert solar energy into clean hydrogen energy is of considerable significance in environmental science. However, it is still a challenge due to their relatively high costs, low efficiencies, and poor stabilities. In this study, a metal-free carbon quantum dots (CQDs) modified graphitic carbon nitride photocatalyst (CCN) was synthesized by a facile method. The characterization and theoretical calculation results reveal that the incorporation of CQDs into the g-C₃N₄ matrix significantly improves the charge transfer and separation efficiency, exhibits a redshift of absorption edge, narrows the bandgap, and prevents the recombination of photoexcited carriers. The hydrogen production and simultaneous degradation of methylene blue (MB) or rhodamine B (RhB) in simulated wastewaters were further tested. In the simulated wastewater, the CCN catalyst showed enhanced photodegradation efficiency, accompanied with the increased hydrogen evolution rate (1291 µmol·h⁻¹·g⁻¹). The internal electrical field between the g-C₃N₄ and the CQDs is the main reason for the spatial separation of photoexcited electron-hole pairs. Overall, this work could offer a new protocol for the design of highly efficient photocatalysts for dye wastewater purification with simultaneous hydrogen production.

C₁₆H₁₅NO, monoclinic, P2₁/c (no. 14), a = 5.9233(3) Å, b = 14.5788(9) Å, c = 14.7095(9) Å, β = 99.073(2)°, V = 1254.34(13) ų, Z = 4, R_gt (F) = 0.0600, wR_ref (F ²) = 0.1512, T = 170 K.

An integrated method was employed to comprehensively elucidate the complicated mechanisms of Shan Zha for the treatment of various disorders at the system level.

C₂₂H₂₂FeO, monoclinic, P2₁ (no. 4), a = 10.204(3) Å, b = 5.7956(16) Å, c = 14.591(4) Å, β = 97.876(10)°, V = 854.7(4) ų, Z = 2, R _gt (F) = 0.0676, wR _ref (F ²) = 0.1647, T = 170 K.

C₂₂H₂₇ClN₂O₃, orthorhombic, P2₁2₁2₁ (no. 19), a = 8.6797(3) Å, b = 9.8809(3) Å, c = 24.7824(8) Å, V = 2125.42(12) ų, Z = 4, R _gt (F) = 0.0478, wR _ref (F ²) = 0.1082, T = 170 K.

C₁₄H₁₉NO₃, monoclinic, Cc (no. 9), a = 11.1235(5) Å, b = 15.3724(5) Å, c = 8.1110(3) Å, β = 109.3980(10)°, V = 1308.21(9) ų, Z = 4, R _gt (F) = 0.0300, wR _ref (F ²) = 0.0703, T = 170 K.