Controllable self-assembly of BiOI/oxidized mesocarbon microbeads core-shell composites: A novel hierarchical structure facilitated photocatalytic activities

The electrostatic induced self-assembly method is successfully applied to prepare core-shell hierarchical structure of BiOI/OMCMB (Oxidized mesocarbon microbead) composites (MB), in which BiOI nanosheets were uniformly immobilized on the surface of OMCMB. The low-priced graphite carbon OMCMB played a crucial role in inducing and assembling the core-shell structure of the MB composites, which not only effectively improved the conductivity of the catalyst but also enhanced the stability of BiOI in the catalytic process. The photocatalytic degradation of tetracycline hydrochloride (TH) revealed that the hierarchical structure of OMCMB and BiOI promoted the photogenerated charge separation, and enhanced the photocatalytic performance of BiOI. And sample MB-3 had the highest photocatalytic performance with TH degradation of 96.8% under the visible-light irradiation for 60 min. MB-3 remains favorable photocatalytic activity after four cycles. Moreover, based on the related optical and electrical characterization analysis, a possible photocatalytic mechanism about MB composites was proposed tentatively.