The Preparation And Photocatalytic Performance Of Graphene-TiO₂ Nanocomposite Photocatalysts With Activity Facet

Photocatalytic technology has been recognized as an effective means to environmental pollutant control and remediation. Due to its chemical stability, low cost and strong oxidizing characteristics, TiO2 has been widely used as photocatalyst over the past several decades.In this work, anatase TiO2 photocatalysts with activity facet were synthesized by using a facile microwave-assisted hydrothermal method. And the products were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), UV-Vis Diffused Reflection Spectroscopy (UV-Vis DRS) and High Resolution Transmission Electron Microscopy (HRTEM), respectively. The photocatalytic activity of the products was investigated on the degradation of Rhodamine B (RhB). The photocatalytic activity of products under the visible light was improved by changing the experiment conditions. The main results of the experiments were as followed:(1) A series of anatase TiO2 samples with (100) facets were prepared by using a microwave-assisted facile hydrothermal method. And then four characterization methods, which were XRD, SEM, UV-Vis DRS and HRTEM, were adopted to characterize the prepared samples. Photocatalytic activity of products was investigated by the experiment of the degradation of Rhodamine B (RhB). It turned out that anatase TiO2 sample with (100) facets had a good photocatalytic activity under the xenon lamp irradiating. Among the samples, the photocatalytic activity of which was synthesized by the reaction condition of 36 h,180℃ and 7 mL of HF was the best and the degradation rate had reached to 99.9% in 40 min.(2) The anatase TiO2 samples with (101) facets prepared by using a microwave-assisted solvothermal method were characterized by XRD, SEM, UV-Vis DRS and HRTEM, respectively. The samples were used as the photocatalyst in the experiment of degradation of Rhodamine B (RhB) under the xenon lamp irradiating, which was evaluated the photocatalytic activity of products. The experiments showed that the samples exhibited visible-light driven photocatalytic performance. The sample, synthesized under the reaction condition of 72 h,180 ℃ and 3.2 mL of HF, had better photocatalytic activity compared with others. The degradation rate could reach to 90.4% in 75 min.(3) The microwave-assisted facile hydrothermal synthesis method was employed to compound the anatase TiO2/graphene composite photocatalysts. Using XRD, SEM and UV-Vis DRS to characterize the composite samples was a part of the experiment, and the other was the degradation of Rhodamine B (RhB) using the composite samples as the photocatalyst under the xenon lamp irradiating. The result showed that the addition of graphene made TiO2 attached on the surface of graphene uniformly, and TiO2/G composite photocatalysts, prepared when HC1 was involved in the synthesis reaction, had the most excellent photocatalytic activity.