Synthesis of recyclable magnetic mesoporous RH-FSBA photoelectrocatalyst with double cavity structure

Highlights: • A RH-FSBA_0.03 photoelectrocatalyst with double cavity structure was synthesized. • This photoelectrocatalyst exhibits ultra-strong enriching property to targeted pollutants. • SPR effect of metallic Ag exists in this photoelectrocatalyst. • The recombination of the photoexcited e^- and h⁺ pairs could be inhibited effectively. • This heterojunction exhibits fast interfacial charge migration. In this paper, a series of BiOCl-Ag/AgBr heterojunctions supported by magnetic mesoporous silica microspheres with double cavity structure (RH-FSBA_x) were successfully synthesized. For the combination of double cavity structure and orderly mesoporous opening structure of magnetic mesoporous RH-FSBA_x photoelectrocatalysts, they exhibited ultra-strong enriching property to targeted pollutants. For the formation of BiOCl-AgBr heterojunctions, superior photosensitization of AgBr and existence of metallic Ag plasmas with surface plasmon resonance (SPR) effect, the photoelectrocatalysts exhibited enhanced visible light photoelectrocatalytic performance. Furthermore, the photoelectrocatalyst can be recycled easily by magnetic separation for its superior magnetic response. Particularly, the magnetic mesoporous RH-FSBA_0.03 photoelectrocatalyst exhibited the highest photoelectrocatalytic activity (k = 1.3 × 10⁻² min⁻¹) in degradation of acid fuchsin (AF) under visible light irradiation, and it was about 4 times of RH-FSB photoelectrocatalyst. Therefore, this novel photoelectrocatalyst can effectively decompose organic pollutants in water system under visible light irradiation by rapid enrichment and efficient photodegradation.