超薄MoS2/TiO2纳米管阵列多维复合体系在光合制氢中的协同催化作用及机理研究

At present, one of the inexpensive protocal for hydrogen generation is to explore the photocatalytic water splitting by simulating the photosynthesis in nature. To achieve the above goal, it is the key to develop a highly stable material with efficient photocatalytic response in visible light region. In order to promote the photocatalytic the activity of conventional TiO2 under visible light, this project will introduce the ultrathin MoS2 nanosheets into the TiO2 nanotubes arrays as visible light sensitive multi-dimensional composite to excavate the catalytic properties of TiO2. The intrinsic relationship among the preparation, structure regulation and photocatalytic performance will be thoroughly understood by changing the combinations of composite materials. Combined with density functional theory (DFT) calculation and experimental investigation, we will investigate the effects of MoS2 nanosheets on the TiO2 band structure itself and the interfacial property between them. Then, the influence on the diffusion and separation of photogenerated electron-hole couples will be analyzed to explore the visible light response mechanism of the composites and provide theoretical inductions on the construction of the highly stable solar water splitting system. The project will provide a novel approach to improve the visible light response of TiO2 nanotubes, and meanwhile enrich the application of ultrathin MoS2 nanosheets in the design of novel photocatalytic materials. Therefore, this project has an important significance and practical prospects in the investigations to expand the performance of titanium based photocatalysis.

利用太阳能模拟光合作用光解水制氢是获取氢能源的低廉途径之一。高效稳定的可见光响应光催化材料是实现太阳能光解水制氢的关键。为提高TiO2纳米管阵列在可见光区的光催化活性，充分利用纳米管阵列的结构优势，本项目拟制备具有可见光响应的TiO2纳米管阵列/超薄MoS2纳米片多维复合材料。通过改变复合材料的结合方式，系统研究制备方法、结构调控和光催化性能三者之间的关系。结合密度泛函理论计算（DFT）和实验协同研究MoS2纳米片调控TiO2纳米管阵列的能带结构、界面性质，进而分析二者复合对光生电子和空穴的有效分离和传输的影响规律，探索复合材料对可见光响应活性的作用机理，为构建高效稳定的太阳能光解水制氢体系提供理论基础。本项目将为拓展TiO2纳米管阵列在可见光响应提供新的思路，丰富超薄MoS2纳米片在新型光催化材料的设计及光催化领域的应用。因此，本项目对扩展钛基光催化剂性能具有重要意义。

氢能作为新型的清洁能源引起了研究人员的广泛关注，通过分解水产生氢气提供氢能是未来非常有前途的方法之一。然而，光、电解水工业仍然受限于其高成本、稀缺资源的贵金属材料催化剂，另外水分解的析氢反应（HER）动力学非常缓慢，导致整体能量转化效率低。因此，开发低廉易得、高效稳定的新型析氢催化材料具有非常重要的意义。通过本项目的实施，我们取得以下进展：（1）C3N4/TiO2纳米带及钼掺杂三维海胆状材料的构筑及光电催化析氢构效关系研究；（2）金属（金属氮化物）/氮掺杂碳纳米孔的构筑及电催化析氢及氧还原的构效关系研究及氮掺杂多孔碳内分子吸附、扩散、反应独特规律的揭示；（3）金属/吡啶炔加成石墨烯（M/PyNG）的构筑及电催化构效关系研究。在该项目的支持下，本项目已发表相关SCI论文11篇，其中包括Adv. Funct. Mater.，J. Mater. Chem. A（3篇），Carbon等国际著名期刊。本项目通过理论计算和实验相结合，为拓展金属氧化物及金属负载碳基催化剂在光、电催化制氢提供新的思路，丰富了金属氧化物及金属负载碳基材料的设计及在光、电催化领域的应用。