摘要
在溶胶-凝胶法基础之上,以尿素为氮源,通过较温和的反应条件来制备氮掺杂TiO2光催化剂。以亚甲基蓝为模型化合物、日光色镝灯为光源,探索了其可见光光催化性能;并用XRD、低温氮气吸附-脱附技术、UV-Vis等表征了其结构特征;同时以对苯二甲酸为探针分子,结合化学荧光技术研究了光催化体系中.OH自由基的变化规律,进一步验证了其光催化活性规律。结果表明:氮掺杂能引起TiO2光催化剂的激发吸收光谱明显红移并具较好的可见光响应性;在不同煅烧温度和尿素/钛酸丁酯物质的量的比条件下,所得样品的光催化活性随着煅烧温度的升高而逐渐降低,随着尿素/钛酸丁酯物质的量的比值的增大而逐渐增强;荧光强度变化规律与光催化活性规律相一致,即光催化体系中.OH自由基的生成量越多,光催化活性越好。
The N-doped TiO2 photocatalyst was prepared based on the sol-gel method in a mild condition with urea as the nitrogen source. The photocatalytic activity to visible-light of the N-doped photocatalyst was investigated using methylene blue as the photodegrading compound, and Dy-lamp as the visible-light source. The structure properties of the photocatalyst were characterized via XRD, low-temperature nitrogen adsorption-desorption techniques and UV- Vis diffuse reflectance spectroscopy. The hydroxyl radical ·OH produced in the photocatalytic system was studied via a fluorescence spectroscopy, and terephthalic acid was used as the hydroxyl radical capturer. The results indicate that the N-doping could make the light absorption of the photocatalyst obviously extended into visible-light region, and increase the visible-light responsive photocatalytic activity. The photocatalytic activity of the obtained photocatalyst was gently weakened with the increasing of calcination temperature, and gently increased with the increasing of molar ratio of urea to Ti [O（CH2）3CH3]4. The variation in fluorescence intensity was consistent with the photocatalytic activity, i.e. the greater the amount of OH, the higher the photocatalytic activity of the N-doped TiO2 photocatalyst.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2008年第4期541-546,共6页
Chinese Journal of Inorganic Chemistry
基金
国家自然自然科学基金(No20676050)
广东省自然科学基金(No05200555)资助项目
作者简介
任凌，女，25岁，硕士；研究方向：纳米材料的合成与应用。
通讯联系人。E-mail：tzhangym@jnu．edu．cn
