BiMO4(M=Nb,Ta)/N2Sx(N=Mo,Sn,Bi)异质结构筑及水环境药物残留的光催化深度降解

It is significant to completely degrade and mineralize of the drug residues because there are a wide variety of pharmaceutical compound with the complex components in water environment. Moreover the by-products due to degradation process are toxicity, even in a lower level of contents. Thus the photocatalyst had to be with the higher redox ability for the purpose to remove the pharmaceutical pollutants. In this project, the novel PN heterostructures of BiMO4(M=Ta,Nb)/N2SX (N=Mo,Sn,Bi)were synthesized by using Tantalate and corresponding metal oxide. In such unique structure, the photocatalytic activity can be increased by synergistic action between electric field formed by the PN heterojunction and the matched struct of the conduction and valence band in the two composite semiconductors. The recombination of photogenerated electrons and holes can be reduced in this PN heterojunction due to the transition of the electrons being consistent with the direction of the built-in electric field in PN heterojunction. The stability can be increased by promoting the separation of electrons and holes and balancing charge and ions through the effect of the ionic coupling. It is expected that a novel photocatalytic material integrated with high redox ability, enhanced catalytic activity, the wide solar light response and good stability will be developed, which will completely degrade and mineralize drug residues in water environments. The results of this project will provide valuable theoretical basis and technical support for the remedy of water environment pollution.

水环境中药物分子，由于种类多、成分复杂、降解过程副产物多、残留物毒性大，深度降解和完全矿化对处理药物残留污染物显得非常重要，因此对催化剂的氧化还原能力提出了更高的要求。本项目面向我国水环境药物污染，选用宽带隙的铋基铌钽酸盐类半导体为基础材料，制备一系列BiMO4(M=Ta,Nb)/N2SX(N=Mo,Sn,Bi) 异质结催化剂。构筑与组分半导体材料的价带、导带位置匹配的PN结，同时形成内建电场，从而拓宽太阳光响应范围，促进电子空穴分离，还可维持材料的电荷平衡和离子平衡，达到提高材料稳定性的目的；通过该研究预计开发出集成高氧化还原能力、高量子效率和宽光谱太阳能吸收以及优秀稳定性等多重功效的具有实用前景的水环境药物残留深度降解光催化剂，本项目的研究成果将为水环境污染治理提供理论基础和技术支撑。

针对水环境中种类多、成分复杂、降解过程副产物多、残留物毒性大的药物分子的深度降解和完全矿化，设计开发铋基负载型光催化体系。研究PN异质结催化体系可见光催化药物残留废水（四环素）的降解机制及污染物净化过程中复杂反应的各种促进和抑制作用机理。结合催化剂分析表征，揭示盐酸四环素降解过程光催化活性位，获得优化的高氧化还原能力、高量子效率和宽光谱太阳能吸收以及优秀稳定性等多重功效的抗生素降解光催化材料。同时使用DFT数值模拟手段，揭示催化剂电子结构及降解机理，以确定光催化剂在抗生素降解反应中的构效关系和决定反应的关键因素，并用于指导光催化材料的设计，在开拓新型光催化体系和开发高效光催化降解抗生素技术方面取得创新性成果。