中文摘要：

利用光化学还原法制备了Ag/TiO2，然后通过乙酸浸渍制备了HAc-Ag/TiO2复合光催化剂.利用X射线衍射（XRD）、透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）和紫外-可见漫反射光谱（UV-Vis DRS）等手段表征了催化剂的性质.以降解水溶液中的甲基橙（MO）为探针反应，考察了催化剂在可见光下的光催化性能.结果表明，乙酸对TiO2的修饰在TiO2禁带中产生了＂带尾＂，使TiO2的禁带宽度发生了显著的缩减；Ag纳米粒子和乙酸共同修饰的HAc-Ag/TiO2样品具有更窄的禁带宽度和更正的价带顶位置；Ag和乙酸的协同作用使HAc-Ag/TiO2具有良好的可见光催化活性：可见光照射2 h后，甲基橙在HAc-Ag/TiO2上的降解率接近100%.

英文摘要：

Ag/TiO2 sample was prepared by photochemical reduction approach, and then the sample was impregnated with acetic acid to obtain the HAc-Ag/TiO2 composite photocatalysts. The samples were characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, UV-Vis diffuse reflectance spectroscopy （UV-Vis DRS ）, X-ray photoelectron spectroscopy （XPS） and Fourier transform infrared（FTIR） spectroscopy. The visible light photocatalytic degradation of methyl orange （MO） in an aqueous solution was used as a probe reaction to evaluate the photocatalytic activity of the obtained samples. It reveals that the modifying of acetic acid can obviously narrow the bandgap of TiO2 via the formation of band tail in the bandgap of TiO2. Especially, the co-modification of Ag and acetic acid resulted in more narrow TiO2 bandgap and more positive top of valence band. The synergistic effects of Ag and acetic acid on TiO2 enhanced the photocatalyst performance of HAc-Ag/TiO2 composite. Under visible light irradiation, nearly 100% of MO was degraded within 2 h on the HAc-Ag/TiO2 photocatalyst.