水杨酸和精氨酸改性二氧化钛颗粒的制备及其在油-水界面的光催化反应

采用浸渍改性法将水杨酸与精氨酸同时接枝到纳米TiO₂表面制备了水杨酸和精氨酸共改性二氧化钛颗粒(TiO₂-SA/Arg), 并采用傅里叶红外光谱(FT-IR)、X射线光电子能谱(XPS)、热失重分析(TGA)、紫外-可见光漫反射光谱(UV-Vis DRS)、扫描电子显微镜(SEM)、高倍透射电子显微(HRTEM)、表面接触角测试及粒度分布分析等技术对材料的形貌、结构及性能进行表征, 同时研究了催化剂对硝基苯的吸附性能及在油-水界面的吸附能力。结果表明: 水杨酸和精氨酸分别以螯合和桥连结构稳定修饰到TiO₂表面, 与未改性TiO₂相比, 水杨酸和精氨酸共改性TiO₂疏水性及分散性更好, 对硝基苯的吸附能力更强, 并可在油-水界面稳定吸附形成O/W型Pickering乳液。研究了Pickeing乳液光催化体系对硝基苯的去除能力, 与悬浮体系相比, 改性颗粒稳定的Pickering乳液体系对高浓度硝基苯去除效率较高。

Titanium Dioxide Particles Modified by Salicylic Acid and Arginine and Their Photocatalytic Reaction on Oil-Water Interface

Salicylate acid and arginine-modified TiO₂ particles (TiO₂-SA/Arg) were successfully fabricated by impregnation approach using salicylate acid and arginine grafted onto the surface of nano-TiO₂. The morphology, structure and properties of modified samples were characterized by means of Fourier-transform infrared spectroscope (FT-IR), X-ray photoelectron spectroscope (XPS), thermogravimetry ansysis (TGA), ultraviolet-visible diffuse reflectance spectroscope (UV-Vis DRS), scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), surface contact angle analysis, and particle size distribution analysis. The nitrobenzene adsorption capacity and the ability to be attracted to the oil-water interface of the modified samples were also confirmed. Results revealed that salicylate acid and arginine were modified to TiO₂ surface by chelation and bridging structure, respectively. The modified TiO₂ had better hydrophobicity, dispersion properties and adsorption capacity of nitrobenzene than the unmodified TiO₂. A stable O/W Pickering emulsion was successfully fabricated via the photocatalyst stably adsorbed to oil-water interface. Nitrobenzene in Pickeing emulsion-based photocatalytic reaction system, stabilized by modified photocatalyst, showed a higher removal rate of high concentrations of nitrobenzene than the suspension system.