TiO2光催化剂因具有活性高、稳定无毒等优点而得到重点研究，在污染治理、光解水制氢等领域极具应用潜力，但目前因存在只能响应紫外光和量子转换效率低两个瓶颈难题而限制了其广泛应用。本项目拟采用第一性原理，系统研究S分别与不同离子共掺杂引起锐钛矿相TiO2晶体结构、能带结构和光谱特性变化的微观机制，以及掺杂原子能级与TiO2能级间相互作用的规律，揭示光激发、光生载流子输运与微观结构及掺杂元素之间的相互关系，分析掺杂影响氧化还原能力的机制，建立相应的理论模型，以获得高效可见光响应型TiO2光催化剂的改性机理；在此基础上优选出3～4 种S与不同离子共掺TiO2的组成，研究其合成工艺，并分析样品的性能及影响光催化活性的微观机理。.本项目的研究方法可有效克服光催化领域研究中普遍存在的盲目性和重复性问题，预期成果将揭示S与不同离子共掺杂影响TiO2光催化性能的本质，为其改性及制备提供理论指导。

TiO2 photocatalyst has attracted much interest for the high activity, chemical stability and nontoxicity, and there are widely potential applications in the fields such as pollution treatment and preparing hydrogen by splitting water. However, widespread applications of TiO2 as photocatalyst has been limited due to its responding ultraviolet irradiation and very low photo-quantum yield value. In this project, First-principles will be performed to investigate the impact and micromechanism of codoping with S and different ion on anatase TiO2 crystal structure, energy band and optical properties, and also the relation of action between doping ion and TiO2 energy level will be studied. The relation among photon exciting, photon-induced carrier movement, microstructure and doping ion will be clarified.The effect mechanism of doping ion on the redox will be analyzed, and the theoretical model will be design to confirm the modification mechanism of the high efficiency and visible-light response TiO2 catalyst. On the basis of above, 3-4 kinds of samples codoping with S and the different ion will be choiced and the synthesizing technology will be studied, the properties and micromechenism affected by the codoping will be analysed..The problems of blindness and repetition existed generally in photocatalytic study will be overcome effectively owning to the method performed in this project. The anticipative results will not only clarify the essence of high photocatalytic property of TiO2 codoped with S and the ion, but also can be used to instruct the modification and preparation.