S、Yb共掺杂TiO2的制备及光催化性能

Preparation and photocatalytic properties of S–Yb co-doped TiO2

摘要:

以钛酸四丁酯、硫脲、硝酸镱为原料，CTAB为软模板剂，采用水热法制备了S、Yb共掺杂的纳米二氧化钛。采用XRD、BET、SEM、TEM-EDS、UV-Vis、PL对样品的结构和性能进行了表征；以亚甲基蓝（MB）为模拟污染物，氙灯（500W）为光源评价样品的光催化性能。结果表明，TiO2为单一的锐钛矿相，S和Yb成功的掺杂进入TiO2晶格中，掺杂抑制了晶粒的生长，减小了TiO2的禁带宽度，增大了样品的比表面积，降低了光生电子与空穴对的复合率，扩大了光吸收范围；当n(S): n(Yb)=2:1.5时得到的2%S/1.5%Yb-TiO2光催化性能最佳，在500 W氙灯下对亚甲基蓝在90 min内的光催化降解效率达到97.75%。

Abstract:

We used CTAB as the soft template and tetrabutyl titanate, Thiourea, and Ytterbium nitrate as raw materials to prepare S–Yb co-doped TiO2 nanoparticles by a hydrothermal method. The structure and properties of the prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy coupled with energy dispersive X-ray spectroscopy (TEM-EDS), ultraviolet–visible spectroscopy (UV-Vis), N2 adsorption/desorption with the Brunauer– Emmett–Teller (BET) method, and photoluminescence (PL). The photocatalytic performance of the sample was evaluated by using methylene blue as a model pollutant and a xenon lamp as the light source. The results showed that TiO2 contained a single anatase phase and Yb and S were successfully doped into the crystal lattice of TiO2. Doping resulted in smaller grains, lower band gap, and larger specific surface area, reducing the probability of recombination of the photogenerated electron-hole. The catalyst with a molar ratio of doped S and Yb of 2:1.5 (2.0%S/1.0%Yb-TiO2) exhibited the best catalytic performance, with a degradation efficiency as high as 97.75 % after being irradiated by a 500 W xenon lamp for 90 min.