短孔道有序介孔碳-CdIn2S4异质纳米复合光催化材料的组装及其净化室内VOCs研究

Indoor air quality within buildings has been paid more and more attention with increasing awareness of the public environment and health. Volatile organic compounds (VOCs) are common hazardous species in indoor environment, which present significant health effects as frequently causing cancer and other sickness. However, the concentration of indoor VOCs usually might be at parts per billion to parts per million levels, which is difficult to be efficiently decomposed by the conventional methods. As an ambient temperature catalytic process, photocatalysis has gained considerable attention in view of air purification even at low concentrations. From the preliminary results obtained by the investigators on the photocatalytic degradation of VOCs with low concentration by UV-light-driven photocatalysts-semiconductor supported carbon nanotubes or silica gel composite materials, it was found that the obtained composite photocatalyst displayed enhanced decomposition activity in comparison with the pure semiconductor, owing to the enhancement of the adsorption and enrichment ability of the composite photocatalysts. However, the solar radiation energy utilization efficiency is limited, primarily because of UV light only accounts for about 4% of the solar radiation energy, while the visible light contributes to about 43%. Novel visible-light-driven photocatalytic materials are therefore needed for more efficient utilization of the visible light solar spectrum. This multidisciplinary proposal seeks to develop novel heterostructured nanoarchitectures for use as novel visible light photocatalysts for indoor VOCs elimination. Thus, a comprehensive research program is planned consisting of the following components: assembly of novel nanostructured photocatalyst by combining short channeled ordered mesoporous carbon with fast adsorption and transmission properties and nano-CdIn2S4 with excellent visible-light-driven photocatalytic activity induced by ultrasound technology, properties measurements, experimental evaluation of adsorption, photocatalytic and mineralization behavior for VOCs. The intellectual merit of the research is to create a novel heterostructured nanoarchitecure with high visible light purification efficiency for VOCs, to discover the relationship among properties, adsorption performance and photocatalytic activity of the photocatalyst, to reveal the reason to enhance its visible light photocatalytic activity and to clarify the relationship among properties of indoor VOCs, adsorption, photocatalytic reaction and mineralization rates on the photocatalyst. The success of this project would provide new research ideas and methods for the design and application of new materials in elimination of VOCs using sunlight and is also very important for understanding the adsorption, migration and photochemical degradation simulation for VOCs in real indoor environment.

本项目针对室内挥发性有机物(VOCs)浓度较低的特点，将短孔道有序介孔碳(SCOMC)对VOCs的吸附富集作用与纳米CdIn2S4对VOCs的可见光催化矿化作用相结合，借助超声诱导技术，实现SCOMC孔道中原位组装纳米CdIn2S4，研制出一种适于净化室内VOCs的异质纳米组装复合光催化材料，从而实现吸附剂与光催化剂的一体化。研究材料的性质及其对典型室内VOCs的吸附、降解和矿化行为，探讨材料的性质、吸附与光催化性能之间的关系，阐述载体SCOMC和纳米CdIn2S4耦合作用机理，揭示材料可见光催化活性提高的本质原因，阐明典型室内VOCs的性质、吸附速率、降解速率和矿化速率之间的关系和VOCs的降解机理，为新型可见光催化材料技术的研发及其应用于室内VOCs净化提供新的研究思路和方法，这对于了解实际室内环境中VOCs在介孔材料孔道中的吸附、迁移、光化学转化降解模拟具有非常重要的研究价值。

随着全球工业化和城市化的飞速发展，环境问题已经成为人类当前亟待解决的主要问题。光催化技术已被证明是解决环境问题的诸多方法和技术中最有应用前景的。而在这种技术中，催化剂的研究至关重要。因此，研究开发新型、高效催化剂及实现其在实际污染控制中的工程化已成为近年来这个领域的研究热点。本项目在实验室优化制备出多种催化剂如金属氧化物、金属氧化复合物、杂原子掺杂碳材料、金属硫化物/碳材料等及其性能研究的基础上将催化剂进行合理地组装，应用于实际污染现场的污染物净化研究。首先直接在钛片上合成出了具有金字塔形(111)暴露面的金红石TiO2薄膜材料，发现光电催化降解染料的性能要高于锐钛矿TiO2纳米管，这主要归功于前者更小的固有电阻；同时合成出组成和形貌可控的CuO/Cu2O复合空心微球可见光光催化剂，发现其具有高效可见光降解甲基橙性能，这主要归因于它独特的空心结构和异质结构；接着以硫脲为唯一掺杂源，合成出了N, S共掺杂石墨化微孔碳纳米球电催化剂，表现出很好的氧还原催化活性，为可控合成杂原子共掺杂其他类型的石墨化碳材料提供借鉴；然后将碳材料与半导体材料进行复合，合成出Zn−O−C键交联的硫铟锌/还原石墨烯复合光催化剂，发现经过还原石墨烯复合之后，复合材料的太阳光催化性能和稳定性均得到大大增强，本研究有助于促进化学交联型光催化剂方法学的发展，同时也能够推动这些光催化剂在实际水体环境净化中的应用可能性；接着将硫铟锌、硫铟钴和硫铟镍与短孔道有序介孔硅（碳）进行组装，发现复合光催化剂对气相二甲苯具有很好地吸附和太阳光催化降解性能，实现了污染物在催化剂上的吸附与光催化氧化的一体化以及原位降解；最后将上述研发的典型催化剂与载体进行优化组装，并基于该复合光催化剂设计并加工了3套光催化集成装备，在典型电子垃圾资源化车间内开展了有机废气污染控制中试研究，发现所采用的光催化集成技术在有效消除电子垃圾资源化过程排放有机废气的浓度的同时实现了VOCs的潜在风险消减。