面向富水环境应用的稀土上转换纳米晶与铋系半导体复合光催化剂的构筑机理及其性能研究

本项目针对常用敏化剂Yb3+在近红外光区与水分子存在光吸收重叠，制约光功能材料在富水环境中的应用，提出将Nd3+-Yb3+协同敏化、Er3+/Tm3+/Ho3+分层掺杂与界面应力调控相结合，构筑808nm激发的核壳结构稀土上转换发光材料（UCNPs），抑制980nm下的热效应和能量损失。通过研究稀土UCNPs与铋系半导体复合材料中各组份之间的能量交换方式，不同组分间的应力对晶体结构、稀土离子能级结构及半导体能带结构的影响，阐明UCNPs对半导体的光催化增强机制，搭建稀土离子间的有效能量传递桥梁，获得可用于富水环境的UCNPs/半导体复合光催化剂，拓宽其在近红外光区的响应范围。考察复合材料对双酚A的光催化性能，探究有机物的降解规律及动力学特性。本研究为利用上转换发光改性半导体光催化性能，实现面向富水环境中的高效能量转化提供了一种可行的策略，也为利用红外光降解有机物的商业化应用提供了技术支持。

In view of the light absorption overlap between common sensitizers Yb3+ and water molecules in the near infrared region, which restricts the application of optical functional materials in aqueous environment. In this project, Nd3+-Yb3+ synergistic sensitization, Er3+/Tm3+/Ho3+ fluoride layered doping and interface stress control are combined to construct core-shell structure rare earth upconversion luminescent material (UCNPs), excited by 808nm to reduce the thermal effect and energy loss under 980nm. By studying the mode of energy exchange between UCNPs and its components in bismuth semiconductor composites, and the effects of stress between different components on crystal structure, energy level structure of rare earth ions and energy band structure of semiconductors. The photocatalytic enhancement mechanism of UCNPs on semiconductors was clarified, an effective energy transfer bridge between ions was built, and UCNPs/ semiconductor composite photocatalysts which can be used in water-rich environment were obtained. The response range in the near infrared region is broadened. Through the investigation of the photocatalytic performance of the composites for bisphenol A, the degradation law and kinetic characteristics of organic compounds were investigated. This study provides a feasible strategy for using upconversion luminescence to modify the photocatalytic performance of semiconductors to realize efficient energy conversion in photochemical reactions in water-rich environments. It also provides technical support for the commercial application of near-infrared photodegradation of organic compounds.