界面调控的Z型TiO2纳米管（带）阵列光电极构筑及协同氧化还原机制

In recent years, the phthalic acid esters (PAEs) and NO3- have caused increasingly serious threat against the safety of water supply. In order to ensure the safety of drinking water, the development of photocatalytic oxidation-reduction technology for effectively removing PAEs and NO3- from water was needed. The graphene(GR) and g-C3N4 quantum dot co-decorated TiO2 nanotube arrays （TNAs）and TiO2 nanobelts （TNBs）photoelectrodes would be fabricated by adsorption reduction and thermal condensation in atmospheric pressure, so as to get Z-type composite GR@g-C3N4/TNAs（TNBs）photoelectrodes with stable oxidation and reduction performance under the illumination of solar light. To clarify the correlations between microstructure and photocatalytic activity,the structure-activity relations between GR, g-C3N4 and TNAs（TNBs）would be studied by SEM, XRD and first principles calculation method. Based on the photoelectric catalysis technology, the synergistic oxidation-reduction system for water treatment was constructed to use effectively the photogenerated holes and charges at the same time. The adsorption, transformation and degradation pathways of dimethyl phthalate (DMP) and NO3- at the surface of the electrode would be studied. The degradation products and reactive species in the oxidation-reduction process would be identified. The synergistic photocatalytic oxidation-reduction mechanism and the photodegradation reaction kinetics model for DMP and NO3- would be discussed. Furthermore, the biological safety of different system would be analyzed. We expect to provide the theory basis and the technical support for new water treatment function material and environmentally-friendly technologies, which was energy-saving, safe and high efficient for the decomposition of DMP and NO3- by regulating the surface-interface with multi-material.

近年来，水中邻苯二甲酸酯（PAEs）和NO3-对供水安全产生了很大的影响。为了开发能够有效去除水中PAEs和NO3-的光催化氧化-还原技术，拟采用原位吸附还原和热缩聚等工艺，在TNAs和TNBs上负载GR和量子点g-C3N4，研制在太阳光下具有高效稳定的氧化还原性能的Z型GR@g-C3N4/TNAs（TNBs）复合光电极。利用SEM、XRD等表征测试技术和第一性原理计算方法研究GR和g-C3N4对TNAs（TNBs）性能的影响，解析电极膜层微观结构和光催化活性之间的关系；构建同时有效利用光生空穴和电子的同步氧化还原净水体系，研究DMP和NO3-在电极表面及反应体系中吸附、转化途径，鉴定降解产物及反应活性物种，解析DMP和NO3-氧化还原机理，建立DMP和NO3-同步降解反应动力学模型。为调控光催化反应，开发高效、安全、节能的新型水处理功能材料和环境友好型净水技术提供理论依据和技术支持。

邻苯二甲酸酯类物质（PAEs）是一类环境内分泌干扰物，被中国环境保护部、美国环保总局等列为优先控制污染物，四环素类抗生素（TCs）已是非常突出的环境问题。近年来，国内外水体中以邻苯二甲酸二甲酯（DMP）为代表的PAEs与以盐酸四环素（TC）为代表的TCs等高风险有机污染物的检出率及检出浓度越来越高，为保证饮用水安全，水中高风险有机污染物的高效去除具有重要的意义。以TiO2为代表的光催化水处理技术具有光催化活性高、无毒稳定、价廉易得及无二次污染的优点，成为国内外给水深度净化处理领域的研究热点。.为了克服无序TiO2催化剂光生电子-空穴复合机率高和可见光利用率低的缺陷，提高光降解高风险有机污染物的能力，采用阳极氧化工艺在中性溶液体系中成功制备了TiO2纳米管阵列（TNAs）和TiO2纳米带阵列（TNBA）光电极，并通过热缩聚、吸附电沉积等工艺制备了rGO/TNAs、g-C3N4/TNAs、rGO/TNBA、g-C3N4/TNBA、rGO@g-C3N4/TNAs和rGO@g-C3N4/TNBA等一系列光电极；利用扫描电子显微镜（SEM）、X-射线衍射（XRD）、X-射线光电子能谱（XPS）、紫外-可见漫反射光谱（UV-Vis/DRS）和电化学工作站等方法对光电极的表面形貌、晶体结构、表面组成、光吸收性能、界面反应过程和电荷传导机理等进行了研究；以DMP、TC等高风险有机物和NO3-为目标污染物，考察了不同光电极制备条件和光催化反应条件对光电极体系光催化性能的影响，并用液质联用仪、活性物质捕获和电子自旋共振(ESR)等技术对光电极光催化降解污染物的机理和作用机制进行了研究。结果表明，g-C3N4和rGO成功负载在TNAs和TNBA光电极表面，制备的三维复合rGO@g-C3N4/TNAs和rGO@g-C3N4/TNBA光电极性能稳定，可见光利用能力明显增强，光电流密度与开路电势显著提高，能够有效的利用太阳光去除水中DMP、TC等有机污染物；光电极易于回收重复利用，技术绿色环保安全可靠，有效促进了水资源的再生循环利用，有助于保障饮用水安全，缓解我国水资源短缺现状，符合当前低碳节能环保的社会需求，具备良好的应用前景。