Preparation of RE/g-C3N4 Photocatalysts by Thermal Polycondensation Method and Its Properties

Abstract

Graphite phase carbon nitride photocatalysts (RE/g-C3N4) doped with different rare earths (RE=La, Ce, Sm, Nd, Eu) were prepared by thermal polycondensation method using rare earth metal nitrate and melamine as raw materials. The photocatalytic performance of RE/g-C3N4 was studied through using photo-degradation reaction of methylene blue (MB) as the evaluation model. The effects of calcination temperature, rare earth elements type and doping ratio on the photocatalytic performance of g-C3N4 were studied. The microstructure of the samples were characterized by FESEM, XRD, UV-Vis, etc. The results show that RE doping can refine the grains and enhance the absorption of visible light. The performance of rare earth doped samples have a significantly improved compared with pure g-C3N4. The performance of La doped samples was better than that of Ce, Sm, Nd and Eu doped g-C3N4. As the temperature increases, the photocatalytic activity of La/g-C3N4 samples increases. When the La doping ratio is 4.0%, the calcination temperature is 590 °C, the degradation rate of The La/g-C3N4 photocatalyst to MB is up to 98.0% within 4 h under visible light irradiation.