Ag-TiO₂ Composite Nanofiber Prepared And Photocatalytic Properties Research

Photocatalytic degradation of pollutants by TiO₂nanomaterials asa novel and developing techonology has become the current researchhot spot, TiO₂nanomaterials could be used not only in the DSSC（DyeSensitized Solar Cells）, sterilization, antivirus, waterproof fabric butalso in the waste water and air pollution treatment owing to its highspecific surface area and good photocatalytic performance. Theresults prove that: the organic pollutant such as halogenatedhydrocarbon, phenolic and formaldehyde can be decomposed into CO₂and water by TiO₂nanomaterials.TiO₂as photocatalyst, the smaller the particle size, the largersurface area, the more active center, and the better photocatalyticactivity. But the nanoparticles obtained through the traditionalmethods such as sol-gel, hydrothermal method in practicalapplication is very limited, because it is easy to aggregate whichresult in specific surface area decreased, beyond that, it is difficult toseparate these particles from solution. TiO₂nanofibers as photocatalytic material, just happened to have the excellentphotocatalytic activity and the advantages of separation recycling,could be mass producted and applicated. In addition, in view of thesun utilization rate of TiO₂is low and their own photocarrier easy tocompound, in this experiment, the method of doping precious metalsAg to TiO₂was used to improve these defects.Electrospinning technology has incomparable advantages inone-dimensional nanomaterials fabrication compared with traditionalmethods such as hydrothermal. Electrospinning has controllability, inthe meanwhile it has other advantages like small investment, simpletechnological process and equipments, and diversification of rawmaterial choice. In this paper, we successfully prepared the differentmorphology of TiO₂nanofibers using sol-gel combined withelectrospinning technology through change the content ofpolyvinylpyrrolidone （PVP） in precursor. The TiO₂nanofibers doped Agalso fabricated, the AgNO₃doping content from 0 to 1.5wt%. Thedegradation of methylene blue as a typical case, the influence ofmorphology and AgNO₃content to photocatalytic effect wasexaminated. The results show that: the photocatalytic activity waspartly influenced by morphology and the amount of AgNO₃. The thinnanofibers with highest specific surface show better photocatalyticactivity than the other morphologies, and for the Ag doped TiO₂ nanofibers, Ag doped not only promoted the transformation ofanatase to rutile, but also greatly improved the photocatalysis activity.When the AgNO₃doping content is 1wt%, photocatalytic activity isthe best.