Engineering bandgap structure of BiOCl nanoplates with oxygen vacancies for accelerated photocatalytic degradation of Rhodamine B

2D BiOCl nanoplates with exposed (001) crystal surface were synthesized via a simple solvothermal method and the photodegradation property can be improved via adjusting volume ratios of ethylene glycol (EG)/absolute ethyl alcohol (EA). The photocatalytic results suggest that the BiOCl prepared by using the ratios (1:2) of EG/EA (BOC-EG:2EA) with exposed (001) plane displays excellent photocatalytic performance and the removal efficiency of RhB reaches 99% for only 10 min under visible light. The enormous improvement of removal efficiency originates from existence of the oxygen vacancies, the narrow band gap, and limited recombination rate of photoexcited electron-hole pairs. Additionally, the superoxide radical anions (·O2-) and photogenerated holes (h+) are confirmed to be the primary active species to accelerate the photoactivity. This work provides a new perspective to fabricate high-efficient photocatalysts used in relative wastewater treatment system.