多酸基配合物与导电聚合物/官能化碳纤维杂化的纳米复合材料制备及其光催化产氢性能研究

The design and fabrication of efficient photocatalysts for hydrogen production under visible light has been the topic in the fields of energy and material chemistry. However, most of single photocatalyst possesses two drawbacks during the photocatalytic process, that is, poor photoresponse to visible light and low quantum. In this program, we intend to design and prepare a series of polyoxometalate (POM)-based complexes and their nanomaterials with excellent photocatalysis property. Considering that the conductive polymers and functional carbon fiber exhibit strong photoresponse under visible light and can separate photogenerated electron-hole effectively and enhance quantum yield, the POM-based complexes nanomaterials are combined with the conductive polymers and functional carbon fiber through in-situ chemical oxidation polymerization or a simple colloidal blending process to obtain the p–n heterojunction nanosized composite materials as photocatalysts. Photocatalytic H2 production by the p–n heterojunction photocatalysts were systematically investigated under visible-light irradiation. The effects of components, structures and morphologies etc for these photocatalysts on the photocatalytic activities were explored in order to illustrate the intrinsic relation between the structures and the photocatalysis properties. The photocatalysis mechanism will be revealled. This project will extend the potential application for the hybrid nanosized composite materials constructed from polyoxometalate-based complexes and conductive polymer/functional carbon fiber in the field of energy.

在可见光下能够高效光催化水解产氢的光催化剂的设计制备是当前能源和材料化学领域的热点课题。然而多数单一光催化剂在光催化过程中存在着在可见光区内光响应弱和量子产率低的问题。本项目拟设计合成一系列具有良好光催化性能的多酸基配合物及其纳米材料，利用导电聚合物和官能化的碳纤维在可见光区域内具有较强的光响应且可促进光生电子-空穴分离、提高量子产率的特点，通过原位氧化聚合或胶体混合法将多酸基配合物纳米材料与导电聚合物（聚吡咯、聚苯胺及共聚物）或官能化的碳纤维结合在一起，制备出p-n异质结构的纳米复合材料光催化剂。系统研究所得的多酸基纳米复合材料在可见光范围内的光催化产氢性能，探索不同类型纳米复合材料的组成、结构、形貌等对光催化产氢性能的影响，力图阐明该类p-n异质结构光催化剂的结构与性能之间的内在关系，揭示光催化机理。本项目对扩展该类纳米复合材料在能源领域的应用具有重要意义。

本项目设计合成了两类含N/O给体基团的酰胺有机配体：一类是柔性/半刚性的双吡啶双酰胺、双吡嗪-双酰胺、双吡唑双酰胺配体、双咪唑双酰胺配体和不对称的吡啶/吡嗪-多唑单酰胺配体等N给体配体，另一类是同时包含酰胺基团和羧酸基团的吡啶/吡嗪-酰胺羧酸等N/O给体配体，并将其在水热、溶剂热条件下与多金属氧酸盐及过渡金属进行配位组装，构筑了一系列结构新颖的多酸基金属有机功能配合物。并通过元素分析、红外光谱、热重分析、单晶X射线衍射以及粉末X射线衍射等进行了结构表征。通过调节有机配体的配位基团、配位取向、长度和刚/柔韧性及多酸的结构、尺寸、电荷等，研究上述因素对目标多酸基配合物结构的影响，总结其组装规律，实现该类多酸基功能配合物的可控合成；通过原位氧化聚合或胶体混合法将多酸基配合物与导电聚合物（聚吡咯、聚苯胺及共聚物）或官能化的碳纤维结合在一起，制备出p-n异质结构的纳米复合材料光催化剂。对所合成多酸基功能配合物材料的电催化、光催化性能进行系统研究，初步探索了这些光催化剂的组成、结构等对光催化性能的影响。本项目对扩展多酸基功能配合物材料在光催化、电催化、吸附和能源材料等领域的应用具有重要的意义。