Soft BiOBr@TiO2 nanofibrous membranes with hierarchical heterostructures as efficient and recyclable visible-light photocatalysts

Abstract

TiO₂-based heterojunction fibrous membranes with stable hierarchical nanostructures, excellent visible-light-driven photocatalytic activity, and easy-recycling ability would hold great promise in environmental remediation; however, it still remains a great challenge to construct such fantastic fibrous membranes. Herein, soft and hierarchical heterostructured BiOBr-anchored TiO₂ nanofibrous membranes (BiOBr@TiO₂ NFM) were fabricated by the sol–gel electrospinning technique combined with a facile successive ionic layer adsorption and reaction (SILAR) process. The well-crystallized BiOBr nanoplates with lamellar structure were uniformly grown onto TiO₂ nanofibers, and the size and amount of BiOBr nanostructures could be finely regulated through rationally adjusting the growth cycles of SILAR. Benefiting from the large surface area, enhanced visible-light response, and intimately connected interfacial heterojunctions, the resultant membranes exhibited superior photocatalytic performance for rhodamine B (RhB) degradation under visible light irradiation, including a high degradation efficiency of 95.5% within 120 min and excellent reusability in 5 cycles. More importantly, the membranes still maintained good mechanical flexibility and structural integrity after utilization and could be directly extracted from solution. This study may provide a new strategy for the design and fabrication of soft hierarchical nanostructured TiO₂-based fibrous membranes for environmental remediation and other potential applications.