The Preparation Of WO₃/TiO₂-rGO Composite Photocatalyst And The Research Of Photocatalytic Propertyby

This paper firstly prepared graphene oxide（GO） by modified Hummers method.TiO₂ precursor sol was prepared by using four butyl titanate as raw materialcitric and citric acid as hydrolysis inhibitor. WO₃/TiO₂-GO precursor fabricated by adding WO₃ powder and ammonium tungstate hydrate solution with different amount respectively was calcinated and reduced to obtain WO₃/TiO₂-rGO composite photocatalytic materials.WO₃/TiO₂-rGO samples was characterized by X-ray diffraction（XRD）,transmission electron microscope（TEM）, fluorescence spectrum（PL）.The efforts of WO₃ powder adding amount, GO composite amount, calcination temperature on microstructure, surface morphology and photocatalytic efficiency of sample were researched. The main results were summarized as follows:Citric acid replacing the traditional acetic acid and nitric acid has a better inhibitory effect on the hydrolysis of four butyl titanate, solving the problem of uneven distribution of TiO₂ particles on the surface of graphene oxide.When the WO₃ power is used as the source of tungsten, it can be used as the transfer channel of the electron in TiO₂, which can reduce the recombination rate of electron and hole, and improve the photocatalytic property of the material.The best adding amount was 15% for WO₃ power in WO₃/TiO₂-rGO samples. The sample calcined at 450℃ has a lower relative fluorescence intensity, and the photocatalytic performance is better than that of the sample calcined at 400℃ and 500℃.Composite materials prepared by the method of adding TiO₂ precursor sol with ammonium tungstate solution, WO₃ inhibits the growth of TiO₂ grains, the lifetime of the photo induced carriers is prolonged, showing a lower relative fluorescence intensity and a higher photocatalytic activity than that of the UN doped samples, the best adding amount was 10%. The sample calcined at 450℃ has higher photocatalytic activity than the samples calcined at 400℃ and 500℃.The addition of rGO can increase the adsorption rate of pollutant molecules, which is beneficial to the photocatalytic degradation reaction; the formation of rutile phase TiO₂ can be suppressed in the process of calcination, and the grain size of TiO₂ can be reduced; the two-dimensional plane structure of rGO makes the dispersion degree of TiO₂ particles increase, and prevents the agglomeration of TiO₂ particles; the high conductivity can promote the separation of the electron and hole pairs, the addition of rGO samples showed better photocatalytic performance compared with the sample without rGO, the best adding amount was 10%.