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 Ce3+ 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 Ce4+/Ce3+ 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. [Display omitted] • CeO 2 /BiOBr microsphere heterojunctions assembled via one-pot solvothermal route. • CeO 2 can weaken interflake electrostatic repulsion and enlarge special surface area. • Heterojunction and Ce4+/Ce3+ center donate jointly better photocatalytic efficiency. • Mechanisms for heterojunction construction and photodegradation well investigated. [ABSTRACT FROM AUTHOR]