中文摘要：

采用一步水解法制备了无定形TiO2（Am-TiO2）,并运用X射线衍射、X射线光电子能谱、N2吸附-脱附和紫外-可见漫反射光谱等手段对其进行了表征.结果表明,Am-TiO2具有大的比表面积（216m2/g）和丰富的表面羟基/化学吸附的水.与晶态TiO2相比,Am-TiO2的吸收带边明显蓝移（411nm→378nm）,禁带宽度增加.可见光照射（λ〉420nm）下Am-TiO2样品能快速敏化降解罗丹明B（RhB）,近一级反应速率常数（k=0.0325min？1）分别为锐钛矿相TiO2和商业化P25的6.5倍和5.2倍,且RhB降解以脱N-乙基和发色团开环同时进行;而晶态TiO2体系中,RhB以发色团开环为主.矿化/脱N-乙基分别是由于RhB通过-COOH或-N＋Et2与催化剂表面作用所致.Am-TiO2催化剂重复使用性能良好,重复使用4次后,RhB的降解速率没有明显变化.

英文摘要：

Amorphous TiO2 （Am-TiO2） was prepared via a simple step through hydrolysis.The as-prepared Am-TiO2 was characterized by X-ray diffraction,X-ray photoelectron spectroscopy,UV-visible diffuse reflectance spectroscopy,and N2 adsorption-desorption.Large surface area （216 m2/g） and abundant surface hydroxyl group/chemical adsorbed water were observed on Am-TiO2.Compared with crystallized TiO2,the adsorption edge of Am-TiO2 exhibited a blue shift （from 411 to 378 nm）.Rapid photo-sensitized degradation of rhodamine B （RhB） was achieved on Am-TiO2 under visible light （λ 420 nm） irradiation.The pseudo-first-order rate constant （k=0.0325 min-1） was 6.5 and 5.2 times that of anatase and TiO2 P25,respectively.Moreover,both the N-deethylation and cleavage of chromophore ring structure of RhB were observed on Am-TiO2 while only the latter path predominated on crystallized TiO2.The difference between cleavage of chromophore ring structure and N-deethylation was ascribed to different anchoring groups of RhB on TiO2 through-COOH and-N＋Et2,respectively.Testing in 4 recycle experiments,the degradation rate of RhB did not change significantly,indicating the excellent stability and reusability of the Am-TiO2 photocatalyst.