石墨相氮化碳的结构调控及其可见光催化性能研究

Study on structural control of graphite phase carbon nitride and their visible light photocatalytic properties

通过X射线衍射(XRD),扫描电子显微镜(SEM)和X射线光电子能谱(XPS)的表征,发现g-C3N4-TH,g-C3N4-CU,g-C3N4-CA,g-C3N4-HAc具有类似的片层结构.紫外-可见漫反射吸收光谱(UV-Vis DRS)得出制备样品的禁带宽度呈现:g-C3N4>g-C3N4-TH>g-C3N4-CU>g-C3N4-HAc>g-C3N4-CA.荧光光谱(PL)分析得出g-C3N4-CU的光生电子-空穴的分离效率要高于g-C3N4.以15 mg/L甲基橙为模拟污染物考察所制备材料的可见光催化性能,结果发现g-C3N4-CU的降解性能最好,是g-C3N4降解效率的3.2倍.

Thiourea(TH),urea(CU),citric acid(CA)and acetic acid(HAc)were selected as structural control agents and mixed with melamine.g-C3N4-TH,g-C3N4-CU,g-C3N4-CA and g-C3N4-HAc and g-C3N4 materials were in-situ prepared by thermal polymerization.The results of X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and scanning electron microscope(SEM)exhibited that g-C3N4-TH,g-C3N4-CU,g-C3N4-CA and g-C3N4-HAc samples displayed a similar lamellar structure.Ultraviolet-visible diffuse reflection absorption spectrum(UV-Vis DRS)analysis showed that the band gap values of the prepared samples were as follows:g-C3N4>g-C3N4-TH>g-C3N4-CU>g-C3N4-HAc>g-C3N4-CA.Photoluminescence(PL)spectrum analysis indicated that the separation ability about photogenic electron-hole of g-C3N4-CU was higher than that of g-C3N4.15 mg/L methyl orange as the simulated pollutant,and the visible light catalytic performance of the prepared materials was investigated.It was found that the degradation performance of g-C3N4-CU was the best among the above-prepared samples,and the degradation efficiency of g-C3N4-CU was 3.2 times as much as that of g-C3N4.