氮-硫共掺杂二氧化钛光催化剂的制备及其可见光催化活性

采用研磨煅烧法,以硫脲(TU)作为氮源和硫源,H2TiO3(HT)为TiO2的前驱体,制备了不同TU/HT比例的N,S共掺杂TiO2光催化剂(NS/TiO2);利用X射线衍射仪、透射电镜、X射线光电子能谱仪、拉曼光谱仪、紫外-可见吸收光谱仪等分析了NS/TiO2的晶体结构、显微形貌、典型元素的化学状态以及光谱性质;利用BET法测定了NS/TiO2的比表面积,同时测定了其在可见光照下催化降解罗丹明B的活性.结果表明,当TU/HT质量比为0.5时,NS/TiO2的光催化活性最佳,光照70min时的罗丹明B降解率为44.4%.氮元素以NH3形式吸附在TiO2表面,硫元素以S6+形式存在,部分S6+取代Ti 4+的位置.与此同时N,S共掺杂使得TiO2的禁带宽度减小,可见光催化活性提高.

Fabrication of nitrogen and sulfur codoped titanium dioxide and its visible light photocatalytic activity

A series of visible light photocatalysts of TiO2codoped with N and S（denoted as NS/ TiO2）were prepared by facile grinding-calcination method with thiourea（TU）as the source of sulfur and nitrogen and H2TiO3（HT）as the precursor of TiO2.The crystal structure,micromorphology,chemical state of typical elements,and spectrometric properties of as-prepared NS/TiO2photocatalysts were analyzed by means of X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,Raman spectrometry,and ultraviolet-visible light absorption spectrometry.The specific surface area of as-prepared NS/TiO2photocatalysts was determined by BET method,and their catalytic activity towards the degradation of Rhodamine B under visible light irradiation was evaluated.Results show that as-prepared NS/TiO2photocatalyst with a TU to HT mass ratio of 0.5∶1exhibits the highest photocatalytic activity and provides a Rhodamine B degradation rate of 44.4% after 70min of irradiation.Besides,N in the form of NH3is adsorbed on the surface of TiO2,and S exists in the form of S6＋and partially substitutes Ti 4＋in TiO2lattice.In the meantime,N and S codoping contributes to reduce the prohibited bandgap of TiO2thereby increasing its photocatalytic activity.