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以钛酸丁酯、硝酸锌和硫脲为原料,采用溶胶-凝胶法制备了不同n(Zn)/n(Ti)的Zn、S共掺杂的TiO_2光催化剂。采用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、激光拉曼光谱(FT-Raman)、紫外-可见漫反射(UV/vis DRS)等对催化剂的结构和光吸收性能进行了表征。结果显示,Zn和S在TiO_2纳米颗粒中均匀分布,Zn以ZnO形式存在,而S以SO2-4形式存在,共掺杂未改变TiO_2的锐钛矿结构。Zn和S共掺杂后,TiO_2纳米颗粒的晶粒变小。由于Zn的掺杂,在TiO_2禁带中产生了杂质能级,降低了纳米材料的禁带宽度,抑制了光生电子和空穴的复合,从而提高了光吸收效率。而S的掺杂,增加了催化剂表面的酸性位,有利于光催化活性的提高。掺杂了Zn、S的TiO_2光催化甘油水溶液制氢的效率远高于纯TiO_2。在氙灯照射下,3%Zn、S共掺杂催化剂的产氢速率可达到150.5μmol/(h·g)。
Zn, S co-doped TiO 2 photocatalysts with different n (Zn) / n (Ti) were prepared by sol-gel method using butyl titanate, zinc nitrate and thiourea as raw materials. The structure of the catalyst was characterized by transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, FT-Raman, UV / And light absorption properties were characterized. The results show that Zn and S are uniformly distributed in the TiO 2 nanoparticles, Zn is present in the form of ZnO, and S is present in the form of SO 2 -4, co-doping does not change the anatase structure of TiO 2. After co-doping Zn and S, the grains of TiO 2 nanoparticles become smaller. Due to the doping of Zn, impurity levels are generated in the forbidden band of TiO 2, which reduces the forbidden band width of the nanomaterials, inhibits the recombination of photogenerated electrons and holes, and improves the light absorption efficiency. The doping of S increases the acidic sites of the catalyst surface, which is favorable for the improvement of photocatalytic activity. The doping efficiency of Zn, S TiO 2 photocatalytic glycerol aqueous solution is much higher than pure TiO 2. Under xenon lamp irradiation, the hydrogen production rate of 3% Zn, S co-doping catalyst can reach 150.5μmol / (h · g).