Gd2O3 nanoparticles modified g-C3N4 with enhanced photocatalysis activity for degradation of organic pollutants

Gd 2 O 3 nanoparticles modified g-C 3 N 4 photocatalytic composites were synthesized by a simple one-step hydrothermal method. The structure, morphology, optical properties of the prepared photocatalyst were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM) and X-ray photoelectron spectroscopy (XPS). The result demonstrates that gadolinium is mainly dispersed on the surface of g-C 3 N 4 in the form of Gd 2 O 3 , and does not destroy the lattice structure of g-C 3 N 4 . Besides, the gadolinium can cause the red shift of the absorption edge of light, narrow the band gap, and increase the separation efficiency of the photogenerated electron and hole of g-C 3 N 4 . Especially, the specific surface area of g-C 3 N 4 can be significantly increased. Furthermore, g-C 3 N 4 /Gd-0.05 displays the highest photodegradation performance when it is used for degradation of methyl orange (MO), methylene blue (MB) and Rhodamine B (RhB). The photodegradation rate of g-C 3 N 4 /Gd-0.05 composites is 72.4% for MO, 95.5% for RhB, 100% for MB after 120 min under visible light ( λ > 420 nm) irradiation. Narrow band gap promotes the separation of photogenerated electron and hole, which enhances the photocatalytic activity of g-C 3 N 4 . It is noted that g-C 3 N 4 /Gd-0.05 exhibits excellent photocatalytic stability by the photocurrent and the cyclic photodegradation of MO. Gd 2 O 3 nanoparticles modified g-C 3 N 4 photocatalytic composites were synthesized by a simple one-step hydrothermal method. It has high photocatalytic activity and photocatalytic stability to a variety of organic pollutants under visible light. • Rare earth Gd doped GCN was prepared by a facile one-step hydrothermal. • The optimal ratio of GdN 3 O 9 ·6H 2 O and GCN was determined. • The highest photodegradation rate of 72.4% is about 3 times larger than pure GCN. • The fermi level narrows the band-gap value of pure GCN.