氮掺杂碳点修饰改性钨酸铋的光催化性能研究

Photocatalytic Activity of N-doped Carbon Quantum Dots Modified Bismuth Tungstate

用超声法制备了氮掺杂碳量子点(N-CQDs)/钨酸铋(Bi_2WO_6)复合光催化剂。通过SEM、XRD、IR、XPS和UV-Vis对样品形貌、结构、组成和光学性能进行表征,并以可见光催化降解罗丹明B(Rh B)考察其光催化活性。实验结果表明:NCQDs与片状Bi_2WO_6杂化形成了N-CQDs/Bi_2WO_6复合光催化剂;与单一Bi_2WO_6相比,N-CQDs/Bi_2WO_6表现出更高的光催化活性,其中0.3%-N-CQDs/Bi_2WO_6催化反应的一级反应速率常数达7×10-3min-1,是纯Bi_2WO_6的3.6倍。光催化活性提高归结于:N-CQDs高度分散在Bi_2WO_6表面上形成界面相互作用,及N-CQDs上转换性能和良好的电子传输能力与Bi_2WO_6光催化性能的协同作用。

The N-CQDs/Bi2WO6 composite photocatalysts were successfully synthesized by using a liquid ultrasonic method. The prepared samples were characterized by SEM, XRD, IR, XPS, UV-Vis and photogradation of Rh B for morphological, comprehensive structural and visible-light properties. The results showed that the N-CQDs/Bi2WO6 composites were formed via the hybridization of N-CQDs and flaky Bi2WO6. The N-CQDs/Bi2WO6 photocatalysts possessed enhanced photocatalytic activity than the single phase Bi2WO6 under visible light, and the 0.3%-N-CQDs/Bi2WO6 showed the highest photocatalytic activity with a k=0.007 min^-1, the value of which was as 3.6 times as that of the pure Bi2WO6. The enhanced performance could be attributed to the interfacial interaction produced by high-dispersed N-CQDs on the surface of Bi2WO6 and the synergy effect of its good capability of electronic transmission and up-conversion fluorescence of N-CQDs with Bi2WO6 photocatalytic properties.