CQDs/Bi₂WO₆异质结纳米片的水热制备及可见光活性增强机制  

Hydrothermal Preparation of CQDs/Bi2WO6 Heterojunction Nanoplates and Mechanism of Enhanced Visible Light Photoactivity

作　　者：孙健哲 李雪松 

机构地区：[1]哈尔滨师范大学,化学化工学院,黑龙江 哈尔滨

出　　处：《材料科学》2020年第5期333-341,共9页Material Sciences

摘　　要：日益严重的环境污染正威胁着人类健康。光催化技术在废水处理、空气净化等环境治理领域具有广阔的应用前景。针对Bi2WO6纳米光催化材料存在的载流子复合率高和可见光催化活性低的实际问题,基于碳量子点(CQDs)的光电优势,可控制备CQDs/Bi2WO6异质结纳米片。利用水热合成技术,选取柠檬酸和乙二胺制备碳量子点,以二维片层状Bi2WO6为耦合基底,研究CQDs制备条件和修饰条件对异质结构CQDs/Bi2WO6光活性的影响。结果表明,经200℃水热1 h制备的CQDs的修饰量为7 wt%,与Bi2WO6在150℃水热6 h制得样品光活性最高,其在可见光下光催化降解4-氯酚(4-CP)活性是未改性Bi2WO6的3.2倍。利用XRD、TEM、BET、DRS及电化学测试等表征手段,研究了CQDs修饰对Bi2WO6的表面组成、比表面积、光吸收能力和载流子分离效率的影响规律,探讨了可见光活性增强机制。Increasingly serious environmental pollution is threatening human health. Photocatalytic tech-nology has a broad application prospect in waste-water treatment, air purification and other en-vironmental treatment fields. In order to overcome the practical problems of Bi2WO6 photocatalyst including high carrier recombination rate and low visible light photoactivity, CQDs/Bi2WO6 hetero-structure nanoplates were controllably synthesized by hydrothermal method using two-dimensional lamellar Bi2WO6 as the coupling substrate, based on the photoelectric advantages of carbon quantum dots (CQDs). CQDs were prepared by hydrothermal method using citric acid and ethylenediamine as precursor. The effects of preparation and modification conditions on the photoactivity of CQDs/Bi2WO6 were investigated. When modification amount of CQDs prepared at 200?C for 1 h was 7 wt%, CQDs/Bi2WO6 was obtained through the hydrothermal process at 150?C for 6 h, which shown the highest visible light photoactivity for 4-CP degradation, reaching to 3.2 times of pure Bi2WO6. By means of XRD, TEM, BET, DRS and electrochemical tests, the effects of CQDs modification on the surface composition, specific surface area, optical absorption capacity and carrier separation efficiency of Bi2WO6 were investigated, and mechanism of enhanced visible light photoactivity was also discussed.

关 键 词：Bi₂WO₆ CQDs 异质结 可见光响应 光催化降解 

分 类 号：O64[理学—物理化学]