Research On The Photocatalytic And Lithium Storage Properties Of Nano-Titanium Dioxide/Porous Carbon Nanofiber Composites

As we known, nano-titanium dioxide (TiO2) is playing an important role in treating contaminated water, polluted air, photocatalytic decomposition of water for hydrogen, storage of solar energy, photoelectric conversion and the lithium-ion batteries, therefore, nano-titanium dioxide has always been the hot topic. However, there are several problems in the application of nano-TiO2, such as agglomeration, poor recycling, low photocatalytic efficiency and low cycle capacities, which have limited the wholescale applications of TiO2. The composites of nano-titanium dioxide and porous carbon nanofiber dramaticlly improve the photocatalytic efficiency and electrochemical performance.In this paper, titanium oxoacetate/polymethyl methacrylate /polyacrylonitrile [TiO(OAc)2/PMMA/PAN] were frabricated by electrospinning and sol-gel methods. The nano-titanium dioxide/porous carbon nanofibers photocatalysts (H-TiO2/PCNFs) were obtained through the subsequent hydrolysis, preoxidation and carbonization of electrospun TiO(OAc)2/PMMA/PAN nanofibers. The composites of nano-titanium dioxide/porous carbon nanofibers (TiO2/PCNFs) for lithium-ion battery were also obtained through the subsequent preoxidation and direct carbonization but without hydrolysis treament of electrospun TiO(OAc)2/PMMA/PAN nanofibers. Variations in morphology, crystal structure, and chemical composition of nanofibers were characterized with FESEM, TEM, XRD and FT-IR, respectively. The photocatalytic activity and electrochemical performance of H-TiO2/PCNFs were separately characterized by photocatalytic degration of methyl orange solution under the UV irradiation and the assembled 2025 button batteries by Land test system. The results show that the surface of the as-spun TiO(OAc)2/PMMA/PAN nanofibers is rough, and shrinked after preoxidation at 280℃for 5.5h. After hydrolysis and carbonization at 600℃for 2h, the diameter of H-TiO2/PCNFs is 600nm, which is porous, covered and interspersed with TiO2 nanoparticles of 5nm. The photocatalytic activity of H-TiO2/PCNFs is higher than that of H-TiO2/CNFs under the same experimental conditions. The TiO2/PCNFs for lithium-ion battery has almost the same morphology, and the TiO2 nanoparticles of 11nm are uniformly distributed in the nanofibers. The result of electrochemical test shows that TiO2/PCNFs have better electrochemical performance and stability than that of TiO2/CNFs.