三维石墨烯电容吸附耦合光催化同步氨氧化-硝酸盐还原机制

It is a key and urgent scientific problem to realize pollutant enrichment and efficiently catalyze in environmental chemistry. To solve the adsorption and exhaustive conversion of inorganic nitrogen on the electrode surface due to the repulsion, this project will employ capacitive adsorption coupling with photoelectrocatalytic technique to overcome this problem. After adsorption and saturation, remove the power supply, connect the electrode plate with a wire, and the electrons move from the negative pole to the positive pole. Photogenic carriers are generated under irradiation. Under the action of plate bias, photogenic electrons flow from photoanode (the negative pole of ammonia nitrogen adsorption) to photocathode (the positive pole of nitric acid nitrogen adsorption). The applied bias can cause band bending and help the oriented transfer of the photogenerated electrons, decreasing the recombination of the photogenerated electron–hole pairs. The nitrate can be reduced to nitrogen gas on cathode and ammonia nitrogen was oxidized by photohole. Finally, inorganic nitrogen was completely converted to N2. Modulation electrode material structural characteristics, photoelectric catalysis reaction conditions, combined with in situ analysis techniques. The mechanism of inorganic nitrogen denitrification and how to prevent recombination of the photogenerated electron–hole pairswill be studied. It will provide theoretical guidance for the degradation of nitrogen pollution.

如何有效实现污染物富集及高效催化，是环境化学亟待解决的关键科学问题。针对光电催化深度脱氮过程中，硝酸氮、氨氮因静电斥力无法在光阴、阳极有效吸附及高效脱氮的问题，本项目拟以三维分级孔石墨烯基材料为双功能电极，利用电容去离子技术将硝酸氮、氨氮富集在正、负极材料表面及内部孔道。吸附饱和后，移去电源，用导线连接极板，电子由负极向正极移动；在光作用下，产生光生载流子，在极板偏压的作用下，光生电子由光阳极（吸附氨氮的负极）流向光阴极（吸附硝酸氮的正极），并在光阴极将硝酸氮还原为氮；光阳极产生的空穴与氨氮发生氧化反应，最终实现水中氨氮氧化与硝酸氮同步还原，并实现电容去离子电极再生。调变电极材料结构特性、光电催化反应条件，结合原位动态分析技术，研究两种污无机氮的电极材料表面的吸脱附行为和界面的电子转移，探究污染氮催化脱氮反应过程及机理，阐明光电协同机制对光生载流子复合抑制作用，为无机氮的降解提供理论指导。

水资源是人类赖以生存的根本，是生产生活关键的资源。随着工业经济和社会的快速发展，水资源污染问题日益加重，已成为全球面临的最大资源危机之一。本项目将电容去离子技术与光电催化技术结合，调变电极材料结构特性、光电催化反应条件，结合原位动态分析技术研究污染氮的电极材料表面的吸脱附行为和界面的电子转移，探究污染氮催化脱氮反应过程及机理，阐水中污染氮的催化降解机理。水电容去离子技术是一种新兴的水处理技术，通过双电原理可以有效富集和去除环境水体中的污染物的方法。基于三维石墨烯材料本项目扩展设计一系列对重金属离子具有高效率电容去除能力的法拉第与碳基复合电极材料，用于水体中重金属离子的去除，并进一步的研究电极材料对重金属离子的去除机理。以上研究成果为实现水体环境中过量污染物的治理提供了新的处理技术方案和有效的理论实验数据，具有较好的应用前景。