Highly efficient and reusable BiOCl photocatalyst modulating by hydrogel immobilization and oxygen vacancies engineering

Abstract

Abstract Photo-induced oxygen vacancies (OVs) are widely introduced as active sites in BiOCl to improve photocatalytic performance. Herein, we propose a strategy to take advantage of OVs of BiOCl nanosheets, which are immobilized in the network of water-rich calcium alginate (CA) hydrogel beads. By modulating the porous structure of the hydrogel, the OVs irradiated by UV light on the surface of BiOCl can be rapidly diffused to the deep inner of the beads, and then they disappear after the beads are immersed into the water for hours, which further enables the regeneration of even better BiOCl-CA beads. This reactive cyclic channel in a water-rich environment improves the transport of photogenerated carriers and achieves excellent cyclic photocatalytic performance. This work not only improves the recovery efficiency of photocatalytic materials but also puts forward a new system of BiOCl based hydrogel beads that can be used repeatedly in wastewater treatment.