Abstract

The structural and optical properties of colloidal Ag₂S quantum dots in different environments are studied. With the help of transmission electron microscopy, X-ray diffraction analysis, and X-ray Energy-Dispersive analysis, the formation of Ag₂S quantum dots with average size of 2–3 nm with monoclinic crystal lattice, and Ag₂/SiO₂ core–shell systems based on them, has been enstablished. A change in the luminescence quantum yield of the quantum dots in the case of a change of the surface environment is shown. Decoration of TiO₂ nanoparticles with a size of 10–15 nm with Ag₂S quantum dots is performed and the effect of the structure of the interfaces of the quantum dots and their environment (2-mercaptopropionic acid, water, ethylene glycol, SiO₂ dielectric shells with thicknesses of 0.6 and 2.0 nm) on the formation of TiO₂–Ag₂S heterosystem is analyzed. The signs of charge phototransfer upon adsorption onto the surface of TiO₂ nanoparticles are found for the Ag₂S quantum dots passivated with 2-mercaptopropionic acid. The signs of appearance of reactive oxygen species as a result of charge phototransfer in a TiO₂–Ag₂S heterosystem are found based on the observation of photobleaching of methylene blue upon excitation of the system from the region outside of TiO₂ fundamental absorption.

中文翻译：

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用于光催化应用的胶体 Ag2S 量子点的发光特性

摘要

_{研究了胶体Ag 2} S量子点在不同环境中的结构和光学性质。借助透射电子显微镜、X射线衍射分析和X射线能量色散分析，形成了平均尺寸为2-3 nm的具有单斜晶格的Ag _{2 S量子点，以及Ag 2} /SiO ₂基于它们的核壳系统已经建立。示出了在表面环境改变的情况下量子点的发光量子产率的变化。用Ag ₂修饰尺寸为10-15 nm的TiO _{2纳米粒子}进行了S量子点以及量子点界面结构及其环境（2-巯基丙酸、水、乙二醇、厚度为0.6和2.0 nm的SiO ₂介电壳）对TiO ₂形成的影响-Ag ₂ S 异质系统被分析。对于用 2-巯基丙酸钝化的 Ag ₂ S 量子点，发现了吸附到 TiO _{2纳米颗粒表面后电荷光转移的迹象。TiO 2} –Ag ₂中电荷光转移导致活性氧物质出现的迹象_{S 异质系统是基于在从 TiO 2}基本吸收之外的区域激发系统时观察到亚甲蓝的光漂白而发现的。