石墨烯／二氧化钛复合光催化剂的制备及可见光催化性能研究

以钛酸正丁酯为钛源，采用一种简单的原位水解技术制备了石墨烯／二氧化钛复合光催化剂．通过XRD、SEM、TEM、Raman、PL和UV-vis光谱仪等分析手段对产物进行了表征，并测试了该复合光催化剂在可见光区对染料罗丹明B的光催化降解性能．实验结果表明：制备的复合光催化剂主晶相为锐钛矿型二氧化钛，石墨烯表面富集的二氧化钛颗粒尺寸约为10-20nm左右，均匀弥散、形成一层致密的氧化钛膜层．样品降解罗丹明B测试结果表明，石墨烯与二氧化钛的复合，一方面使得二氧化钛光催化剂在可见光区的吸收大大增强，另外，石墨烯的存在能够促进二氧化钛半导体中电子和空穴的有效分离，并且在一定程度上提高了污染物在半导体表面的富集效率，从而使石墨烯／二氧化钛复合光催化剂对降解罗丹明B表现出良好的光催化活性．

Preparation and photoactivity of graphene/TiO2 hybrid photocatalysts under visible light irradiation

Graphene/TiO2 hybrid photocatalyst was successfully synthesized through a simple in situ hydrolysis method by using TBOT （Ti（OC4H9）4） as Ti source. The physical and chemical properties of graphene/TiO2 hybrid photocatalyst were carefully studied by XRD, SEM, TEM, Raman spectra, photoluminescence spectra （PL） and UV-vis diffuse reflec- tance spectra （DRS）. The photocatalytic activity of the as-prepared products was evaluated by photocatalytic decolorization of Rhodamine B （Rh B） aqueous solution at ambient temper- ature under visible light irradiation. The experimental results showed that the main phase of as-prepared products is antase TiO2 and the TiO2 nanoparticles, with the diameter about 10 -20 nm, attached on the surface of graphene matrix and formed a layer of dense titanium di- oxide. The photocatalytic activity research showed that, with the cooperation of sp2 hybridcarbon in graphene conjugate structure, the hybrid photocatalyst exhibited an enhanced light response and absorption in visible light region. Moreover, the existence of the graphene can promote effectively separation of electron and hole, and enhance the absorption efficiency of organic pollutions on the surface of TiO2 to a certain extent. Thus, the graphene/TiO2 hy- brid photocatalyst exhibited an enhanced Rh B degradation photoactivity under visible light region.