层状结构矿物剥离-负载磷酸银光催化性能及调控

A method will be developed to efficiently improve the removal of contaminants from water by utilizing the inner areas of the layered clay and the fine photocatalyst particles inside the layers. The nano-carbon fiber and catalyst (silver phosphate) will be fixed between the lamellars of layered clays, and then the layer will be exfoliated; finally, the layered material is obtained as nano-sheet covered with nano-carbon fiber net and dotted with catalyst. The nano-sheet may be reformed as open-pore structured cluster, which will be characterized and analyzed. The diffusion of the contaminant in the cluster will be studied as well. The nano-carbon fiber stringed Ag3PO4 particles can efficiently separate the photogenerated carriers from the semiconductor surface. When the electrons quickly transferred to a carbon fiber, it participate in the photocatalytic reduction reaction, and separated holes in Ag3PO4 surface participate in the oxidation reaction, resulting in a better light degradation of pollutants effects. The pore shape and diameter will be characterized under various degrees of exfoliation. The relationship between the pollutant dispersion and the pores character will be revealed. The relation of adsorption performance and the catalysis will be revealed as well. Moreover, the synergistic effect of layered material contents on the degredation will be investigated. The photogenerated holes and electrons blocking mechanism will be explored to improve the catalyst stability and catalytic rate.

本项目以快速降解水中污染物为目的，以充分利用层状矿物（膨润土和水滑石）层间内表面和高效利用光催化剂为手段，通过在层状矿物层间域内引入纳米碳纤维网络和催化剂（磷酸银），并固相剥离，构建一种具有新型开放孔道的催化剂载体和异质结构光催化剂。在纳米碳纤维网络中固定半导体催化剂并覆盖于粘土矿物片层内表面，利用纳米碳纤维高效分离半导体表面的光生载流子，将电子快速转移至碳纤维，富集至纳米碳纤维网络的电子可以被快速导出并参与光催化还原反应，而分离后的空穴在Ag3PO4表面参与氧化反应，从而提高Ag3PO4的光稳定性并提高污染物降解速度。项目以染料和苯酚为研究对象，拟考察在不同纳米碳纤维/网络/片层情况下，孔道直径/形状对污染物扩散和吸附之间的影响；光催化剂对有机污染物的催化降解的影响和制约因素。结合不同层状材料组成对磷酸银的协同作用，探讨催化剂稳定性和催化速度，揭示光生空穴和光生电子复合阻隔机理。

项目以快速降解水中污染物为目的，充分利用层状矿物（膨润土和水滑石）层间内表面和光催化剂，通过在层状矿物层间域内引入纳米C3N4和催化剂（磷酸银），并剥离，构建一种具有新型开放孔道的催化剂载体和异质结构光催化剂。以此材料为研究对象，对染料等污染物进行降解，研究结果表明，膨润土及水滑石等在经过离子交换和液相处理后，可以获得较好的剥离纳米片层。在片层表面负载的催化剂在与硅氧表面结合后，大大提高了分散程度，并有较好的吸附效果。水滑石材料经过剥离获得二维纳米片层同时提供异质结结构，大大提高了催化效率。经过分析，层表面的炭质材料及C3N4的存在对光生载流子的分离有明显效果。研究揭示了磷酸银在该条件下催化降解染料以及苯酚等有机物的规律及影响因素；基本探明光生空穴和光生电子复合阻隔/传导机理。通过调节负载的炭质材料的量可以调控光生载流子的移动范围及复合程度。本项目为可见光催化剂磷酸银的应用提供了更好的理论基础，可以大大降低应用中银的使用量及磷酸银的稳定性。在项目的资助下，项目开发了相应的光催化装置，为下一步的工程应用提供了可能。项目发表论文14篇，申请专利5项，获得授权4项，培养研究生7名，均超额完成计划任务。