插层法制备g-C3N4/高岭石复合材料及其光学性能

高岭石表面与层间具有较高的活性和良好的规范性,因而适合对其进行化学修饰,在催化剂负载方面值得深入研究.本文以甲氧基嫁接的高岭石为前躯体,采用置换插层法制备出高岭石/三聚氰胺插层复合物,进一步在550 ℃煅烧获得g-C3N4/高岭石复合光催化剂.利用X射线衍射、傅里叶红外和热重-差热分析等手段对复合光催化材料进行表征,并对其光催化性能进行研究.结果表明,当高岭石与光催化剂前驱体三聚氰胺质量比为1∶1和1∶2时,较难缩聚得到g-C3N4;然而,当高岭石与三聚氰胺质量比为1∶3、1∶4、1∶5时,可获得不同g-C3N4占比的复合材料,其整体分散状况因高岭石的加入而有效改善,这表明高岭石的加入能有效避免g-C3N4的团聚.所制备的高岭石负载石墨相氮化碳光催化材料具有较好的光学性能,在探索经济、高效、绿色矿物基复合光催化剂方面研究具有重要意义.

Preparation of g-C3N4/kaolinite Composite by Intercalation Method and Its Optical Performance

The surface and the interlayer of kaolinite has high activity and good normality which is so suitable for chemical modification, hence, the catalyst loading is worthy of in-depth study.Using methoxy-grafted kaolinite as precursor, the kaolinite-melamine composites were prepared by the displacement intercalation method.Then the kaolinite-melamine composite materials was calcined in the 550 ℃ to obtain the g-C3N4/kaolinite composite materials.The prepared composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetry and differential scanning calorimetry (TG-DSC), and their photocatalytic performance were also studied.It is indicated that it is difficult to synthesize g-C3N4 when kaolinite-melamine ratios are 1∶1 and 1∶2;while the composites with different ratios of g-C3N4 will be get when the mass ratio of kaolinite and melamine is 1∶3, 1∶4 and 1∶5, respectively.Kaolinite can effectively prevent the reunion of g-C3N4, and improved dispersion condition can be obtained due to the addition of kaolinite.The prepared g-C3N4 /kaolinite composites have good photocatalytic performance which has great significance in the research of mineral based economic, efficient and green catalyst.