杂多酸修饰氮化碳复合材料的形貌可控合成及其降解水中有机污染物同时产氢的可见光活性与机理

Photocatalysis using semiconductor photocatalysts driven by visible-light has been considered as one of promising strategies toward solving the future energy and environmental problems. Recently, graphitic carbon nitride has attracted intensive interest for its visible-light photocatalytic activity. However, large mass transfer resistance and few numbers of active sites of graphitic carbon nitride are disadvantageous to visible-light photocatalytic reaction. In addition, the visible-light photocatalytic activity of graphitic carbon nitride is low owing to the fast recombination of photogenerated carriers. Morphology controllable synthesis and electron capture agent modification are good methods to enhance the visible-light photocatalytic activity of graphitic carbon nitride. To comprehensively enhance the visible-light photocatalytic activity of graphitic carbon nitride, in this project, the nanotubes, hollow spheres, porous structure of carbon nitride are prepared by hydrothermal treatment, template, and self-assembly techniques, and then the heteropolyacid molecules are introduced into carbon nitride by impregnated grafting. Thus, a series of heteropolyacids modified carbon nitride composites with different geometry are obtained according to the above two steps. The visible-light photocatalytic activities of these as-prepared materials are expected to be significantly improved by controlling the synthesis conditions. The visible-light photocatalytic activity and mechanism of simultaneous aqueous organic pollutants degradation with hydrogen evolution using the as-prepared materials are the important content in this project.

可见光诱导的半导体光催化作用是解决未来环境污染和能源危机的有效途径，而石墨相氮化碳的可见光活性引起了人们浓厚兴趣。然而，石墨相氮化碳较大的传质阻力和较少的活性点数量不利于可见光催化反应的进行。而且，光生载流子的快速复合导致石墨相氮化碳的可见光活性非常低。形貌可控合成和电子捕获剂修饰都是提高石墨相氮化碳可见光活性的有效途径。为全面提高石墨相氮化碳的可见光活性，本项目首先采用水热法、模板法、自组装法制备出纳米管、空心球、多孔结构氮化碳，然后通过浸渍嫁接法将具有较强电子捕获能力的杂多酸分子引入至氮化碳中，从而制备出一系列具有不同几何构型的杂多酸修饰氮化碳复合材料。通过控制合成条件，所制备材料的可见光活性有望得到显著提高。所制备的光催化剂降解水中有机污染物同时产氢的可见光活性与机理研究是本项目的重点内容。

在本项目的研究中，研究团队紧密围绕项目研究目标开展了一系列创新性研究工作。在光催化剂构建研究中，研究团队使用低成本原料，通过简单的合成策略成功开发出一系列具有优异可见光活性和稳定性的氮化碳基光催化剂，并将其应用于各种单组分和多组分光催化系统。在光催化性能研究中，研究团队将所制备光催化剂应用于各种单组分和多组分光催化系统，包括有机污染物降解、产氢、Cr(VI)还原、降解有机污染物同时产氢、降解有机污染物同时还原Cr(VI)，并提出协同光催化反应机制。在项目执行期间，研究团队发表学术论文13篇，授权发明专利6项。