Internal electric field and oxygen defect synergistically optimized of BiOCl/BiOIO3 heterojunctions for enhancing charge transfer: Insight into a nature-derived method for Fermi level modulation

It is particularly significant that the enhancement of charge transfer efficiency and visible light absorption ability on the removal of organic pollutants by semiconductor photocatalysts, for which the interfacial electric field modulation and defect engineering are the linchpins. Herein, we first report the introduction of oxygen defects to regulate interfacial electric field assisted by nature-derived reduction method with green tea extracting solution. Interestingly, the continuously adjustable visible light response, oxygen defect content, and internal electric field intensity for the as-designed heterojunctions are achieved by simply tuning the concentration of the extract solution. The extract modification BiOCl/BiOIO3 heterojunctions exhibit more efficient photogenerated charge transfer, stronger light-harvesting capacity, and superior photocatalytic performance for ciprofloxacin removal compared with the original BiOCl/BiOIO3 heterojunctions. Deep insights into synergistic promotion of steering charge transfer from the perspectives of oxygen defect introduction and internal electric field modulation are unfolded, exclusively shedding new light on the green bio-inspired tactics for promoting the photoelectrochemical property of semiconductor photocatalysts.