Highly Flexible, SnO2/BiOBr Core-Shell Heterostructured Lignin-Based Carbon Nanofibrous Membrane Driven by LED Light for Pollutant Degradation

A highly flexible lignin-based carbon nanofibrous membrane functionalized with SnO 2 /BiOBr core-shell heterostructure (CNFs@SnO 2 /BiOBr) was fabricated via coaxial electrospinning and solvothermal synthesis. By positioning the SnO 2 precursor in the shell layer during electrospinning, rapid and stable stabilization of the lignin nanofiber at a rate of 1°C/min was achieved, significantly reducing the high-energy consumption constraints of traditional preparation processes. Experimental results demonstrated that the CNFs not only enhance light absorption capacity and promote electron transfer but also effectively suppress the recombination of electron-hole pairs at the SnO 2 /BiOBr heterojunction, thereby improving charge separation efficiency. Under LED light irradiation, the CNFs@SnO 2 /BiOBr membrane exhibited a degradation efficiency of 87.3% for Rhodamine B within 100 min with optimal performance at natural pH (6.2), increasing to 93.0% at pH 3.5. Additionally, the composite membrane maintained a stable efficiency of 84.5% after five cycles at pH 6.2, owing to its outstanding photocatalytic performance and self-supporting structure (tensile strength of 0.601 MPa and elongation at break of 6.10%). This research offers a sustainable approach to designing flexible photocatalytic membranes for wastewater treatment, emphasizing environmental and green significance while enhancing biomass resource efficiency. By improving heterojunction catalytic efficiency and addressing the challenge of recovering traditional powders, it demonstrates promising applications in advancing sustainable wastewater treatment solutions.