Fabrication Of Hierarchical TiO₂ Nanofibrous Membranes For Photocatalysis

With the rapid development of modern industry, large number of pollutants were emissions to the environment, and caused serious environmental pollution, especially air pollution and water pollution. It caused huge economic loss and serious threat to human survival and health, so environment protection gradually has become the people cared focus. Traditional methods for disposing pollutants include chemical oxidation, adsorption by activated carbon, biological treatment, supercritical oxidation method and some other methods, but there are many shortcomings of these methods, such as unfully degradation, high cost and secondary pollution, etc. Semiconductive photocatalysis has been widely used in air cleaning, water purification and antibacterial areas as a new type of pollution treatment technology. With the excellent chemical stability, good photocatalytic activity, and nontoxicity, titanium dioxide has great practical prospects.There are three kinds of the existence of TiO2 photocatalyst: particles, film and fiber. However, TiO2 nanofiber has higher BET surface area and photocatalytic activity. Many scholars focus their attention on the TiO2 nanofiber photocatalyst. Electrospinning has attracted extensive attention in the past two decades as a simple and straight forward method to produce nanofibers with dimensions ranging from the microscale to the nanoscale. With the development of the electrospinning technique, TiO2 have been prepared into nanofibrous structure. Electrospinning has become a conventional method for rapid preparation of TiO2 nanofibers. But, there are also some problems of spinning difficulty, membrane defects and low of production efficiency.In this article, we firstly combine sol-gel method and electrospinning technique to fabricate PVP/TiO2 nanofiber membranes. And then the composite membranes were calcined at 600 °C for 1 h by gradually increasing the temperature with a heating rate of 2 °C/min in air to remove the organic components. Finally, using the synthesis of bifunctional benzoxazine monomer and a certain content of TiO2 nanoparticles to modify the inorganic TiO2 membranes.In this contribution, we demonstrated an intriguing approach for constructing flexible TiO2 NPs decorated TiNF with a hierarchical mesoporous structure under mild conditions to be severed as photocatalysts for dye pollutants degradation. The electrospun TiNF were severed as templates and a synthesized BA-a was used as a novel carrier and fixative for non-agglomerated growth TiO2 NPs. Benefiting from the large surface area, high porosity, homogenous, and stable nanofibernanoparticle composite structure, and robust mechanical properties, the as-prepared anatase TiNFNP exhibited excellent photocatalytic activity towards methylene blue including fast degradation within 30 min, good reversibility in 4 cycles, and easy-to-recycle. Moreover, the the degradation procutes have been analysized and TiNFNP exhibited better photodegradation performance towards MB compared with commercial catalyst P25. Sigificantly, the successful synthesis of such fascinating materials may provide a versatile platform for further development of nanofibrous membrane-based photoreactors towards water and air pollutants treatment.