极性半导体/碳纳米复合材料的可控制备与光降解气相碳氢污染物性能

Solar photocatalysis is a promising approach for the degradation of atmospheric hydrocarbons (HC). However, conventional photocatalytic materials are still facing the problem of low adsorption and low activity on degradation of small molecular HC. In our preliminary studies, we found that ferroelectric niobates with well-fabricated nanostructures can photo-activate C1-C4 at ambient conditions, and, the performance can be improved by introducing C3N4. This project aims to further build polar semiconductive and carbonous nano-composite materials with well assembled interface states followed by comprehensively investigate the photocatalytic transformation performance and mechanism of the gaseous HC. First, increase the surface area and expose the active crystal faces by morphology control of the polar semiconductors and then extend the scope of solar energy utilization by welding with carbon materials. Second, perform the structural analysis and photo-physical characterization in conjunction with the measurements of HC adsorption as well as photocatalytic conversion activities upon the composite materials. Surface alkaline decoration as well as co-catalysts loading will be employed during this stage in order to improve the activities. On this basis, study the structure-property relationship of the catalytic materials by controlling reaction conditions and further disclose the underlying mechanism with the aid of in-situ spectroscopic characterizations. Last, by optimizing the reaction system and process parameters to obtain high efficient photocatalytic materials with broad solar spectrum response. The knowledge developed in this project will be valuable for the treatment of atmospheric HC.

利用太阳能的光催化技术是降解大气中低浓度碳氢污染物的有效方案，但常规的光催化材料在降解小分子碳氢方面仍存在吸附难、活性低的问题。我们在前期研究中发现铁电铌酸盐等极性纳米结构对C1-C4有良好的光催化活化作用，并且引入氮化碳后可使活性增强。本项目拟进一步构建具有良好界面接触的极性半导体/碳纳米复合材料并系统研究气相碳氢的光催化转化性能与机理。首先, 通过极性半导体的形貌调控增大比表面积、暴露活性晶面, 结合碳材料添加拓宽纳米复合材料的光能利用范围；然后，进行结构分析和光物理性能表征并测试复合材料对碳氢的吸附富集与光催化转化能力，测试过程中将对材料表面进行必要的碱性位修饰和助催化剂担载以提高活性；在此基础上，通过反应条件控制研究催化材料结构与性能之间的关系规律并借助原位谱学表征开展机理研究；最后，通过优化反应体系和工艺参数获得高效宽广光谱响应的光催化材料，为大气中碳氢污染物治理提供借鉴。

利用太阳能的光催化技术是降解大气中低浓度碳氢污染物的有效方案，但常规的光催化材料在降解小分子碳氢方面仍存在吸附难、活性低的问题。在本项目执行期内，我们围绕极性半导体及其与碳复合纳米光催化材料的设计构建与光催化性能及机制，设计合成了系列极性半导体/碳纳米复合材料，研究了其形貌和表界面调控规律、复合比例与催化性能等。取得的创新成果有：(1)通过极性半导体纳米光催化材料的多尺度设计实现了室温条件下甲烷的高效氧化;(2)通过N-TiO2@C复合纳米片的设计合成实现了温和条件下选择性催化硝基苯还原反应;(3)通过铁镍氧化物多孔超薄纳米片的可控合成提升了电催化水氧化活性和经济性;(4)通过对极性半导体光电特性的研究发现中心对称钒酸铋材料具有应变诱导的反常光伏效应;(5)以反铁电铌酸银陶瓷为例阐明了铁电光伏和应变光伏的差异等。发表SCI收录论文34篇，其中大类I区论文12篇，期刊封面或背封面论文8篇。这些结果为深入推进相关工作提供了知识储备和人力资源。