高比表面多级结构(001)TiO2电极的设计与高活性催化降解研究

TiO2 with dominant {001}facets enjoys the advantages of high catalytic activity and strong oxidation ability. The same time, its use was often limited by the low surface area. Based on this, an idea put forward through the design of an advanced multi-layer structure. First, the carbon aerogel (CA) with three-dimensional network porous structure was chosen as the substrate, then a one-dimensional vertical growth of rutile TiO2 nanorods (NRs) was build on the surface as a rigid bracket. Next, TiO2 nanobranch with nearly 100% exposed (001) facets was modified on the outer wall of the nanorods. Final, (001)-TiO2 NRs/CA electrode material with high surface area and high activity was obtained.Field emission scanning electron microscope (FESEM), selected area electron diffraction (TEM) and X-ray diffraction (XRD) were used to observe the morphology and crystal phases of the material. The specific surface areawas were calculated by Brunauer-Emmett-Teller (BET) method. The relationship between the structure and the photocatalytic activity, such as the absorption range, charge transfer , energy transfer and so on was clarified in detail. The (001)-TiO2 NRs/CA electrode is applied for the photocatalytic degradation of pharmaceutical wastewater pollutants under UV light irradiation. A possible mechanism and degradation pathway is proposed based on the identification of intermediate products.

本项目基于TiO2(001)晶面催化活性高，氧化能力强的特性，但受限于比表面积较低的缺点，提出以三维网络多孔结构的块状碳气凝胶(CA)为基材，在其表面构筑一维直立生长的金红石TiO2纳米棒(NRs)，进一步通过多层结构的设计，在其外壁嫁接TiO2的(001)晶枝，最终得到高比表面高活性以及高暴露度的(001)TiO2 NRs/CA光电电极材料。采用先进的分析手段，详细地表征材料的微观结构和光电化学特性；揭示化学微观结构与光谱吸收范围、电荷转移、能量传递等光催化性能之间的构效关系；并有针对性地选择卡马西平医药废水类污染物为对象，考察对其的光电催化降解效率，解析中间产物与动力学过程，阐明(001)TiO2电极的光电催化特性和作用机理。

本项目以如何实现对环境内分泌干扰物双酚A的高效去除为目标，立足于TiO2(001)晶面的高催化活性和强氧化能力，通过多级结构的设计，制备出具有高比表面积、高晶面暴露度的仿生“树”状结构(001)A/R-TiO2电极以及具有可见光响应的碳量子点敏化(001)晶面TiO2电极。多层次的建构提供了更大的比表面积、更强的吸附行为以及更宽的光吸收范围，交错的能级使得电子和空穴分离，抑制了复合行为，最终获得了增强的光电催化氧化性能，实现了对污染物双酚A宽波长范围内的高效去除。采用先进的分析手段，详细地表征材料的微观结构和光电化学特性；揭示化学微观结构与光谱吸收范围、电荷转移、能量传递等光催化性能之间的构效关系；系统地解析了降解过程中的动力学过程，阐明了(001)TiO2电极的光电催化增强作用机理。