Interfacial internal electric field and oxygen vacancies synergistically enhance photocatalytic performance of bismuth oxychloride

Solar-to-chemical energy conversion is valuable and sustainable strategy for energy and environmental crisis through photocatalysis. The amorphous SnOx modified BiOCl (Sn-BiOCl) full-spectrum-responsive catalysts were designed and synthesized through solvothermal method. The introduced Sn regulates the growth of BiOCl to form ultrathin nanosheets with surface oxygen vacancies. And the surface modification of SnOx induces interfacial internal electric field via charge redistribution on the interface of BiOCl and SnOx to accelerate the photogenerated charge separation. The modification of SnOx decreased work function of Sn-BiOCl and thus elevated its conduction band and valence band simultaneously, leading enhanced photocatalytic reducibility with the improved generation rate of ·O2-. The surface SnOx and oxygen vacancies of Sn-BiOCl broadened light absorption range and enhanced photocatalytic performance synergistically, resulting in 14-fold increased photodegradation rate of phenol compared with pure BiOCl under full spectrum. This method is also able to expand to other metal ions (such as Fe3+, In3+ and Sb3+). This work provides a valuable concept in structure regulating for enhanced photocatalytic performance in the removal of organic pollutants by interfacial internal electric field and surface oxygen vacancies.