导电高分子/ MFeO3纳米半导体异质结光催化材料的制备及性能研究

In viewing of increasingly severe energy and environmental problems, it's significant and meaningful to come up with new visible light-driven photocatalysts. Nano-semiconductor heterojunction-type photocatalysts have got a lot of attention for their unique bandgaps and special electron transmission character. These characters enable them to improve the quantum efficiency significantly and take advantage of visible light more efficiently compared with traditional photocatalysts. In the project, we intend to prepare novel conducting polymer - MFeO3 (M = Bi, Sr, La) nanocomposites with nanojunction structure by a unique process combined a hydrothermal process (or electrospinning technique) and in-situ polymerization method simultaneously. For the prepared nanojunction system, we will investigate the surface and interface interaction between the two different semiconductors; investigate the driving mechanism of local electric field on the photoinduced electron-hole separation; investigate the influence of the bandgap and configuration on the charge separation process; investigate the influence of the morphology and structure of heterojunction photocatalysts on photocatalytic activity, photoelectric properties, bandgap and adsorption, etc. We hope to obtain ecofriendly novel visible-light-driven photocatalysts and proclaim the photocatalytic mechanism through the project. This project is significant and meaningful, because it not only provides an efficient way to fabricate a series of superior visible light-driven photocatalysts, but also can further promote the new function development of inorganic-organic nanocomposites.

研发新型可见光响应的光催化材料对解决环境污染问题具有重要意义。纳米半导体异质结型光催化剂由于其特殊的能带结构和电子传输特征，可克服传统光催化剂量子效率低和不能利用可见光等缺点，而引起人们的广泛关注。 本项目拟利用静电纺丝技术，水热处理技术结合原位复合方法构筑结构新颖、基于导电高分子及MFeO3（M = Bi, Sr, La）系列的纳米异质结复合光催化材料。研究这类材料中不同半导体表面及界面之间的相互作用规律；研究异质结内建电场对光致电荷分离的驱动作用以及能带和构型对异质结电荷分离方式的影响；研究材料的形貌和结构对光催化性能、光电性能、材料的能带结构和光吸收性质的影响规律；揭示光催化反应机理；制备具有高效、可见光响应、可循环利用的环境友好型光催化材料。本项目不仅是对有机-无机纳米复合材料新功能探索的发展，也是构建高效新型可见光光催化材料的一条崭新途径，因而有着重要的科学和实际意义。

本项目采用静电纺丝法、水热法等技术制备了多种基于导电高分子或MFeO3（M = Bi, Sm, La）的纳米异质结复合光催化材料。包括PPy-Ag-TiO2, PANI-CoFe2O4-TiO2，BiFeO3-TiO2, BiFeO3-Bi2Fe4O9, C3N4-Ag-Bi2WO6等多种复合异质结样品，系统研究了异质结内建电场以及材料形貌对研究材料的形貌和结构对光催化性能、光电性能、材料的能带结构和光吸收性质的影响规律结果表明：不论是p-n异质结，还是Z-型异质结均可有效抑制电子空穴复合，促进电子空穴分离，从而导致更高光催化活性。同时材料的含量及形状对材料性能也有一定影响。微球状及纤维状往往表现出更好的光催化性能。此外，通过FDTD模拟，研究了CdSe/ZnS核壳量子点阱内阱外ls-ls能级的光跃迁现象，研究了由Ag 纳米棒/纳米盘复合结构的等离子效应。探讨了石墨烯，以及石墨烯-金属复合材料近红外下的光学性能。通过本项目研究发表SCI论文15篇，培养博士生5人，硕士生4人，获得了系列具有可见光响应、可循环利用的环境友好型光催化材料。为进一步促进光催化材料的发展，打下良好基础。