• 关键词：二氧化钛  表面修饰  纳米粒子  吸附法  芳香族污染物

• 基金项目：国家自然科学基金(No.20177017)

• 郑凤英
• 1. 漳州师范学院化学与环境科学系, 漳州 363000; 2. 武汉大学环境科学系, 武汉 430079

• 李顺兴
• 漳州师范学院化学与环境科学系, 漳州 363000

• 钱沙华
• 武汉大学环境科学系, 武汉 430079

• 邓南圣
• 武汉大学环境科学系, 武汉 430079

• 摘要：利用化学吸附法合成了水杨酸和5-磺基—水杨酸表面修饰的TiO₂纳米粒子.对表面修饰前后的TiO₂纳米粒子,采用红外光谱法、固体紫外-可见漫反射电子光谱法比较其官能团和吸光性能的变化.研究发现,经水杨酸和5-磺基—水杨酸改性后的TiO₂分别呈浅黄色、土黄色,吸收带边发生了明显的红移,吸收边起始点分别延伸至420nm和450nm处,出现—COOTi—和芳香羧酸酯的特征吸收峰;这说明TiO₂表面羟基与水杨酸或5-磺基—水杨酸间发生类似酸和醇之间的酯化反应,分别形成的稳定六元环化合物;在最佳吸附pH值4.0和吸附平衡时间100min的条件下,水杨酸和5-磺基—水杨酸表面修饰的TiO₂纳米粒子对硝基苯酚的吸附率可由改性前的43%分别提高至89%和94%,突破了TiO₂吸附去除芳香族污染物的瓶颈——在吸附剂表面的低覆盖率;同时表层链接苯环的极性减弱,非极性增强,并在水、苯和乙醇中具有良好的分散性.

• Abstract：Nanometer size titanium dioxides modified by salicylic acid （SA） and 5-sulfosalicylic acid （5-SA） were prepared by using surface-modification method. Infrared spectroscopy （IR） and UV-Vis reflectance spectra were used to investigate the structure of the modified TiO₂ nanoparticles and their absorption spectrum. Effects of modification on the adsorption of p-nitrophenol （PNP） and dispersion in water, benzene and ethanol were also studied. The salicylic acid or 5-sulfosalicylic acid is bonded to the surface of TiO₂ nanoparticles, resulting in the formation of a stable, surface sixring complex which color is, respectively, buff and yellow. Through surface modification, the formation of Ti IV-SAand Ti IV-5-SAsurface complex results in a red shift of UV-Vis reflectance spectra, towards the visible region, up to 420 and 450 nm, respectively. Under the optimum pHvalue 4.0, the adsorption rate of PNP by TiO₂ was improved from 43% to 89% and 94%, respectively, through modification by SAand 5-SA. The SA-modified TiO₂ and 5-SA-modified TiO₂ nanoparticles have good dispersive capacity in water, benzene and ethanol.

• Key words：titanium dioxide  surface modification  nanoparticle  photocatalysis

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