TiO2-rGO紫外光催化臭氧耦合高效降解双酚A的研究

采用液相沉积-煅烧法制备二氧化钛-还原氧化石墨烯(TiO₂-rGO)复合光催化剂。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、比表面积与孔隙率分析仪(BET)和紫外-可见漫反射分光光度计(UV-Vis DRS)等对所制备的催化剂进行表征分析。以双酚A(BPA)为模拟污染物，考察了TiO₂-rGO的光催化臭氧氧化降解性能，并通过活性物种捕获实验探究反应机制。结果表明，锐钛矿型TiO₂纳米颗粒成功附着在石墨烯上，颗粒直径约为20 nm；当前驱体溶液中氧化石墨投加量为0.02 g时，样品催化活性最高，反应45 min后双酚A被完全矿化，经过5次循环使用后，仍保持高效催化性能；TiO₂-rGO催化活性的提高主要归因于引入石墨烯后提高了光生载流子的分离效率，促进了光催化与臭氧氧化协同降解；在反应过程中，空穴(h+)和羟基自由基(·OH)是主要的活性物种，·OH对BPA的降解起主导作用。

The Efficient Degradation of Bisphenol A with Ozonation Photocatalyzed by TiO2-rGO Composites under UV Irradiation

TiO₂-rGO composites were synthesized with the liquid phase deposition and calcination method. The as-prepared photocatalysts were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometer (XRD), specific surface and porosity analyzer (BET) and ultraviolet-visible diffuse reflectance spectrophotometer (UV-Vis DRS). The degradation performance of ozonation photocata-lyzed by TiO₂-rGO was investigated using bisphenol A (BPA) as the model pollutant. The reaction mechanism was further explored through the active species trapping experiment. The results showed that anatase TiO₂ nanoparticles about 20 nm in diameter had been successfully anchored on the surface of graphene. The sample obtained when 0.02 g graphite oxide was added in precursor solution exhibited the highest activity and BPA was completely mineralized within 45 min. The catalytic activity of TiO₂-rGO still showed efficient performance after recycling for five consecutive runs. The catalytic activity of TiO₂-rGO was enhanced owing to the improved separation efficiency of photo-generated charges through the introduction of rGO, which benefited the synergistic degradation of photocata-lysis and ozonation. In the reaction process, holes (h+) and hydroxyl radical (·OH)were the main active species and ·OH played a dominant role in BPA degradation.