漂浮型光催化剂制备及其除藻性能初探

以膨胀石墨为载体，蔗糖为外覆炭层前驱物，采用溶胶 炭化一步制备膨胀石墨复合炭基氮、磷共掺杂二氧化钛复合材料（NPT EGC），通过场发射扫描电子显微镜（FE SEM）、氮吸附比表面积及孔容孔径分析仪（BET）、X射线衍射仪（XRD）、紫外 可见漫反射光谱仪（UV vis DRS）、X射线光电能谱仪（XPS）和傅里叶变换红外光谱仪（FT IR）等分析手段进行材料表征，考察不同煅烧温度制备的材料的除藻性能.实验结果表明，NPT EGC复合材料具有蠕虫状的空间结构，表面覆有均匀的二氧化钛颗粒.氮、磷以掺杂的方式进入二氧化钛晶格，其中氮主要通过取代氧的方式，而磷主要通过取代钛的方式.掺杂后复合材料的光能吸收率明显提高.考察不同煅烧温度下制备的NPT EGC材料对铜绿微囊藻的去除性能发现，相对于无催化剂和无光催化负载的情况，复合材料NPT EGC的除藻性能有明显提高，其中以450 ℃下制备的NPT EGC除藻效果最好，9 h的藻细胞去除率在98 %以上.另外，漂浮型的材料易被分离回收，更有利于光能转化，在环境污染治理中应用前景广阔.
The floating photocatalysts of N P codoped TiO2 grafted on expanded graphite C/C composite (NPT EGC) were prepared by a one step sol carbonization method. The catalysts were characterized by field emission scanning electron microscopy (FE SEM), brunauer emmett teller (BET), X ray diffraction (XRD), UV vis diffuse reflectance spectrum (UV vis DRS), X ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT IR). The results show that NPT EGC (N P codoped TiO2/expanded graphite C/C composites) has a worm like 3D structure and TiO2 particles can be seen on the surface of EGC. As for the doping elements, N doped into the TiO2 crystal lattice mainly by the substitution of lattice O while P doped into the TiO2 crystal lattice mainly by the substitution of lattice Ti. After N P codoping, the light adsorption scale of the composites has been significantly improved. The properties of photo catalytic inactivation of algae cells by NPT EGC with different calcination temperature were investigated. Comparing with the condition of no catalyst adding or no photocatalyst loading, NPT EGC composites have a significant advantage in inactivation of algae cells. The optimal type of NPT EGC was synthesized at the calcination temperature of 450 ℃ and the removal rate for 9 h was above 98 %. Moreover, the floating materials could be easily separated and reused, showing great potential for practical applications in environmental cleanup and solar energy conversion