新型二维材料MXene热力学稳定性及光催化性能探究

Thermal Stability and Photocatalysis of a Novel Two-Dimensional MXene

摘要: 本文采用HF刻蚀Ti₃AlC₂材料制备新型二维Ti₃C₂T_x材料，并通过SEM、TEM和XRD对其微观结构进行探究，结果表明Ti₃C₂T_x材料具有类手风琴的二维层状结构。另外，本文采用热重分析对其热力学稳定性进行探究，结果表明Ti₃C₂T_x二维材料表面负载的-F和-OH官能团可通过煅烧处理去除。结合SEM和XRD结果可知，在空气氛围下，当温度高于200℃时，Ti₃C₂T_x二维材料与O₂反应生成TiO₂光催化剂，TiO₂/Ti₃C₂T_x复合光催化剂通过肖特基势垒形成异质结，能够有效提高光生电子和空穴的复合率，TiO₂/Ti₃C₂T_x-200复合光催化剂对甲基橙的降解率可达到58.65%，拓宽了MXene材料在光催化领域的应用。

Abstract: Two-dimensional Ti₃C₂T_x nanosheet was obtained by exfoliation of raw Ti₃AlC₂ powders. The ac-cordion-like structure of as-prepared Ti₃C₂T_x nanosheet was confirmed by SEM, TEM and XRD. Thermal stability analysis suggested that the OH and F groups attached on the surface of Ti₃C₂T_x nanosheets could be eliminated by heat treatment. It is noteworthy that Ti₃C₂T_x nanosheet could react with O₂ to produce a small quantity of TiO₂ when heating up to 200˚C. Furthermore, TiO₂/Ti₃C₂T_x heterojunction photocatalyst was built up by a Schottky barrier between the interfaces of TiO₂ and Ti₃C₂T_x, and the photodegrdation rate of Methyl orange could reach to 58.65%, which was effective to improve the photocatalytic ability than pristine Ti₃C₂T_x.