Synthesis of silica nanofibers-supported BiOCl/TiO2 heterojunction composites with enhanced visible-light photocatalytic performance

Heterogeneous photocatalysts with high catalytic performance and recyclability have attracted widespread attention in organic wastewater treatment. In the study, we designed and synthesized a novel ternary BiOCl/TiO2/silica nanofibers (BTS) composite with enhanced photocatalytic performance via a modified sol-gel method and precipitation/calcination method. In the composite, BiOCl nanosheets and TiO2 nanoparticles are uniformly dispersed on the surface of silica nanofibers in turn, where they are closely combined to form BiOCl/TiO2 heterojunction structure. The composite displays superior degradation performance for rhodamine B (RhB) than bare BiOCl or TiO2 as well as TiO2/silica nanofibers (TS). The excellent photocatalytic performance of BTS is mainly attributed to the enhanced dispersibility of BiOCl and TiO2 given by SNF and the effective construction of BiOCl/TiO2 heterojunction. The radical scavenger and EPR tests found that superoxide radical anions (O2•−) are the dominant active species in the reaction system. It is proposed that the BTS composite shows great potential for wide application in the field of sewage treatment driven by solar energy.