基于离子耦联的钽酸盐基PN异质结的构筑及水环境药物残留的光催化深度降解处理

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。本项目面向内蒙古自治区水环境药物污染，选用宽带隙的钽酸盐类半导体为基础材料，制备一系列基于M(高价)/M(低价)离子耦联结构的MA-MB异质结。通过耦联离子对的原位氧化还原方式实现自掺杂并构筑成内建电场与半导体组分材料的价带、导带位置匹配的PN结，从而拓宽太阳光响应范围，同时促进电子空穴分离，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；本项目的成果为内蒙古面临形势严峻的水环境污染治理提供有价值的数据积累，预计开发出集成高氧化还原能力、高量子效率和宽光谱的太阳能吸收以及优秀的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。

It is significant to completely degrade and mineralize drug residues because there are a wide variety of pharmaceutical compound with the complex components in water environment. Moreover the by-products produced from 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 MA-MB with an Mx+/My+ ions-coupling were synthesized by using Tantalate and correspongding metal oxide.In such unique structure, the visible response can be improved by self-doping through in situ redox way.The photo-catalytic activity can be increased by synergistic action between electric field formed by the PN heterojunction and the matched structure of the conduction and valence band in 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. This project will provide valuable therical and technical support for the remedy of water environment pollution in Inner Mongolia region. It is expected that a novel photocatalytic material integrated with high redox ability,enhaned catalytic activity, the wide solar light response and good stability will be developed, which will completely degrade and mineralize drug residues in water environment.