Multifunctional air-purifying materials have attracted much attention in dealing with indoor air pollution including particulate matter (PM) and hazardous gaseous pollutants (e.g., HCHO), while its development faces long-term challenges of high efficiency and low resistance. Herein, we fabricated a novel hierarchical porous structure TiO 2 –SiO 2 (TS) fiber membrane using a handy electrospinning method. The hierarchical porous structure, comprising micropores and mesopores within fibers and fiber stacking-induced macropores, endows the TS fiber membrane with an astonishing specific surface area of 351.4 m 2 g −1 and a high gas permeability of 1079.4 m 3 m −2 ·h −1 ·kPa −1 . The interconnected pore structure offers additional potential pathways for clean air, which contributes to enhancing PM capture and lower filtration resistance. Consequently, the TS fiber membrane showed a gratifying filtration efficiency of 99.89 % for PM 0.3 and 99.98 % for PM 2.5 at a velocity of 5.33 cm s −1 with an air resistance as low as 69.3 Pa. It is noteworthy that the interconnected microporous-mesoporous structure in fiber also facilitates the adsorption and enrichment of HCHO molecules, thereby increasing the local concentration and thus markedly enhancing the catalytic efficiency. As a result, the membrane demonstrated a photocatalytic removal efficiency of 98.46 % for HCHO under UV light at a high gas velocity of 600 L g −1 ·h −1 . Interestingly, we found that the membrane can maintain good long-term cyclic stability by simply replenishing adsorbed water on the surface. This work would provide new insight for developing advanced multifunctional air purification membranes.
Yinghao Lin,Atian Xie,Jian Xu,Changguo Xue,Jiuyun Cui,Jianming Pan
Oil pollution caused by a large number of industrial activities and oil spill accidents has posed serious harm to the environment and human health. However, some challenges remain with the existing separation materials, such as poor stability and fouling resistance. Herein, a TiO2/SiO2fiber membrane (TSFM) was prepared by a one-step hydrothermal method for oil-water separation in acid, alkali, and salt environments. The TiO2nanoparticles were successfully grown on the fiber surface, endowing the membrane with superhydrophilicity/underwater superoleophobicity. The as-prepared TSFM exhibits high separation efficiency (above 98%) and separation fluxes (3016.38–3263.45 L·m−2·h−1) for various oil-water mixtures. Importantly, the membrane shows good corrosion resistance in acid, alkaline, and salt solutions and still maintains underwater superoleophobicity and high separation performance. The TSFM displays good performance after repeated separation, demonstrating its excellent antifouling ability. Importantly, the pollutants on the membrane surface can be effectively degraded under light radiation to restore its underwater superoleophobicity, showing the unique self-cleaning ability of the membrane. In view of its good self-cleaning ability and environmental stability, the membrane can be used for wastewater treatment and oil spill recovery and has a broad application prospect in water treatment in complex environments.
危险品化学品经营许可证（带存储）