碳量子点敏化二氧化钛复合光催化剂的制备与光催化降解苯酚

为了解决二氧化钛光催化剂存在的禁带宽度大和量子效率低的问题,利用具有优异光吸收性能和电子转移能力的碳量子点改性二氧化钛,可以大幅度提高二氧化钛的光催化性能。本文以富勒烯碳灰为原料,利用混酸回流法制备了一种发黄蓝光的碳量子点,然后采用一步水热法将碳量子点负载于二氧化钛制备了复合光催化剂。借助高分辨透射电子显微镜(HRTEM)、傅里叶变换红外光谱(FT-IR)、紫外可见光光谱(UV-vis)、荧光光谱、X射线衍射(XRD)、X射线光电子能谱分析(XPS)等表征手段对碳量子点和复合光催化剂进行表征,并以苯酚作为模拟废水进行光催化降解实验,结果表明,与纯二氧化钛相比,用碳量子点改性的二氧化钛对苯酚的去除率可提高60%,且其具有较好的稳定性与重复使用性,6次循环利用后仍可达到初次的97.8%。

Preparation of carbon quantum dot sensitized titanium dioxide composite photocatalyst for photocatalytic degradation of phenol

In order to solve the problem of large band gap and low quantum efficiency of titanium dioxide photocatalyst, carbon quantum dot modified titanium dioxide with excellent light absorption properties and electron transfer ability was used, which can greatly improve its photocatalytic performance. In this paper, yellow-light-emitting carbon quantum dots were prepared with fullerene carbon ash as a raw material by mixing acid reflux method. A composite photocatalyst was synthesized by loading carbon quantum dots on the titanium dioxide by one-step hydrothermal method. Carbon quantum dots and composite photocatalysts were characterized by high-resolution transmission electron microscopy (HRTEM), fourier transform infrared spectra (FTIR), ultraviolet-visible spectroscopy(UV-vis), fluorescence spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Photocatalytic experiments were carried out with phenol as simulated wastewater. Compared with pure titanium dioxide, the removal rate of phenol by carbon dioxide modified titanium dioxide could be increased by 60%, and it had excellent stability and reusability, whose utilization rate could reach the initial 97.8% after 6 cycles.