Preparation Of Doped SnO₂-CNT Composites And Studies Of Its Physical And Chemical Properties

As an environmentally friendly semiconductor,tin dioxide?SnO₂?is widely used in transparent conductive films and photocatalysis.In this paper,two kinds of doped tin dioxide-carbon nanotube composites were prepared,and their physical and chemical properties and related mechanisms as transparent conductive films and photocatalysts were studied,including:Fluorine and niobium co-doped tin dioxide?NFTO-CNT?composite film with carbon nanotubes?CNT?was prepared by spray pyrolysis method.Results of the experiments show that the addition of CNT has no effect on the crystal structure of fluorine and niobium co-doped tin dioxide composite film,and the film still maintains the tetragonal rutile structure,but the carrier concentration and carrier mobility increase,resulting in higher conductivity of NFTO-CNT composite film.The transmittance decreases with the addition of CNT.When the same mass of carbon nanotubes is added to the precursor solution of samples,the composite film prepared by selecting 460°C as the coating temperature has better optical and electrical comprehensive performance,and the average visible light transmittance is 81.34%.The surface sheet resistance is 6.4?/?;the residual compressive stress of the film increases with the addition amount of CNT,and the maximum value reacned to-1.33±0.03 GPa when the addition amount is 2.5 g/L.The FTO-CNT composite powder was prepared by one-step hydrothermal method.The experimental results showed that the photocatalytic degradation efficiency of CNTs-loaded samples was improved.When the mass percentage of CNTs added reached8.53%,the optimal photocatalytic degradation efficiency was achieved,and the degradation rate was 1.9 times that of pure FTO composite powder.The structural characterization showed that the FTO nanoparticles grow uniformly and tightly on the surface of the CNTs,and the FTO nanoparticles formed a chemically bonded heterostructure with the CNTs,making the CNTs the recipient of FTO photogenerated electrons,and the FTO photogenerated electrons are efficiently transferred to the CNTs surface.Thereby promoting the separation of electron-hole pairs and improving the photocatalytic activity of the sample.