Abstract: 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.

Key words: 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.