A recyclable T-ZIF-8/SnO2@PAN photocatalytic porous fibrous membrane used for CO2 reduction

The challenge of separating and recycling high-performance photocatalysts often results in resource wastage and secondary environmental contamination. Therefore, the advancement of recyclable photocatalysts has emerged as a frontier area of interest in the domain of photocatalytic CO ₂ reduction. In this work, T-ZIF-8/SnO ₂@PAN-PVP fibrous membranes were constructed with T-ZIF-8/SnO ₂ as a photocatalyst, polyacrylonitrile (PAN) as a matrix, polyvinylpyrrolidone (PVP) as a porogen utilizing electrospinning technique. By regulating the variable parameters, the effects of spinning solution concentration, conductive salt dosage, porogenic agent dosage and their effects on fiber microscopic morphology were investigated, and the process parameters were optimized to obtain the best microscopic morphology, and then the photocatalytic porous fibers were obtained through the water impregnation treatment. A comparative analysis of the CO ₂ reduction capability of photocatalytic powders, fibers, and porous fibers was performed, alongside an exploration of the potential reaction mechanism. The results indicate that the T-ZIF-8/SnO ₂@PAN-PVP porous fiber membrane irradiated by visible light for 4 h demonstrates excellent CO ₂ reduction efficiency, achieving CO, CH ₄, and H ₂ production rates of 14.3, 7.09, and 8.57 μmol·g ⁻¹·h ⁻¹, respectively. Durability tests through repetitive experiments have validated that the T-ZIF-8/SnO ₂@PAN/ZnCl ₂ porous fiber membrane retains over 90 % of its initial photocatalytic activity after four cycles, thereby facilitating the sustainable recycling and reuse of photocatalysts.