g-C3N4-modified BiOCl as a visible light catalyst and its enhanced photocatalytic degradation/sterilization performance†

In an effort to tackle the disadvantages of the narrow photo-responsive range and easy recombination of carriers in BiOCl materials, a simple calcination strategy was adopted to modify BiOCl with g-C₃N₄. BiOCl/g-C₃N₄ nanoplates with a high specific surface area (48.11 m² g⁻¹) and visible photoresponse were obtained. When BiOCl/g-C₃N₄ (mass ratio: 10 : 2) was used, the degradation rate of RhB exceeded 90% within 10 min, while the degradation of MO was completed within 3 h. In addition, 91.35% of the sulfur-oxidizing bacteria could be eliminated. The sheet-to-sheet intercalation structure formed between g-C₃N₄ and BiOCl not only led to an increase in specific surface area but also facilitated electron transfer and carrier separation through the BiOCl/g-C₃N₄ heterojunction. In addition to these experimental evidence, the efficient utilization of solar energy and remarkable separation of photogenerated carriers, confirmed by energy band regulation and significant electron accumulation in the heterojunction (as provided by DFT calculations), contribute to the superior catalytic performance of the BiOCl/g-C₃N₄ heterojunction.