One-pot solvothermal assembly of CeO2/Ce-BiOBr hollow microsphere heterojunctions for efficient degradation of Congo red driven by visible LED light irradiation

Morphology control and heterostructure construction are two essential aspects in designing and synthesizing photocatalysts . Herein, hollow microsphere heterojunctions of CeO 2 and Ce 3+ doped BiOBr (Ce-BiOBr) were fabricated adopting a facile one-pot solvothermal approach. Owing to the positively charged Ce species, the interlamellar repulsion can be reduced and the specific surface area of these microsphere can be increased. The as-generated Ce 4+ /Ce 3+ redox centers can synergistically improve the transfer and separation efficiency of photogenerated carriers. When used to treat Congo red (CR), 0.1CBOB with a Ce/Bi molar ratio of 0.1:1 exhibits the best photodegradation efficiency (94.63%) and kinetic rate (0.01119 min −1 ) under visible light-emitting diode (LED) light irradiation , which are remarkably superior to pure BiOBr and CeO 2 . The results of radical capture experiment show that photogenerated hole (h + ), superoxide radical (·O 2 − ) are the main active species in the process of photocatalytic degradation.