Abstract:

A floating carbon nitride photocatalyst, CNx@mEP, was prepared by the “impregnation-calcination” method using expanded perlite as the carrier, which can be easily recycled and reused. The CNx@mEP was analyzed by Scanning electric microscopic (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Automatic specific surface and aperture analyzer (BET), Fourier transform infrared spectroscopy (FTIR) and UV-vis absorption spectroscopy (UV-vis). The photocatalytic performance of the catalysts was investigated by dye degradation experiments and harmful algae removal experiments. The best photocatalytic performance of the CN2@mEP material was obtained when the mass ratio of dicyandiamide used to the expanded perlite carrier was 2∶1. At a dosage of 4g/L, 67.2% of Rhodamine B, 86.8% of Congo red, 31.2% of Methyl orange dye and 35% of Microcystis aeruginosa were degraded under visible light irradiation for 4h. The floating carbon nitride photocatalyst maintained a relatively stable removal efficiency after 3 reuse cycles.

Key words: carbon nitride, floating carrier, visible-light, dye degradation, algal inactivation

摘要：

针对氮化碳粉末光催化剂在应用过程中存在难以回收、光催化效率不高的问题，本研究采用“浸渍-煅烧”方法，以膨胀珍珠岩为载体，制备了一种方便回收、可多次利用的漂浮型氮化碳光催化剂CNx@mEP。采用扫描电镜（SEM）、X射线衍射仪（XRD）、X射线光电子能谱仪（XPS）、全自动比表面及孔径分析仪（BET）、傅里叶红外光谱仪（FTIR）以及紫外可见近红外漫反射测试（UV-vis）对CNx@mEP进行了分析。分别通过染料降解实验和有害藻类去除实验考察了催化剂的光催化性能。当双氰胺使用量与膨胀珍珠岩载体的质量比为2∶1时得到的CN2@mEP材料光催化性能最好，当催化剂使用量为4g/L时，在可见光下4h降解67.2%的罗丹明B、86.8%的刚果红、31.2%的甲基橙染料和35%的铜绿微囊藻。漂浮型氮化碳光催化剂经过3次重复利用后，仍保持较为稳定的去除效率。

关键词: 氮化碳, 漂浮载体, 可见光, 染料降解, 藻类灭活