High-Performance Photocatalytic Degradation of Organic Pollutant with N-C3n4/Bioclxi1-X S-Type Heterojunction: Self-Induced Internal Electric Field and Stretching Spatial Charge Separation

N-C 3 N 4 /BiOCl x I 1-x S-type heterojunctions were prepared by a facile one-step hydrothermal method. Particularly, the doping of N elements reduced the band gap of g-C 3 N 4 from 2.90eV to 2.03eV, meanwhile the solid solution BiOCl x I 1-x was electrostatically self-assembled on the surface of N-C 3 N 4 with ethylene glycol as solvent. 20%N-BiOCl 0.5 I 0.5 exhibited high activity, the degradation rate of phenol reached 98.53% with 2.5 h of visible light irradiation. Based on the results of various characterizations and DFT calculations, the optimized N-C 3 N 4 /BiOCl x I 1-x sample echibited the effective enhancement in light absorption, electron-hole pairs separation and charge carrier mobility. The charge carriers were generated by the transfer of the photoinduced electron from N-C 3 N 4 to BiOCl x I 1-x across the interface under irradiation, which inhibited the recombination of electron-hole pairs. Thereby, the improvement activity of N-C 3 N 4 /BiOCl x I 1-x was attributed to the formation of S-type heterojunction, the internal electric field based on different Fermi levels between N-C 3 N 4 and BiOCl x I 1- x , as well as band bending and Coulomb force, which together accelerated spatial separation of photogenerated carriers and orderly electron flow.