Synthesis, characterization and photocatalytic properties of nanostructured Sm-doped CdSe

Samarium (Sm)-doped CdSe nanoparticles with different Sm contents were synthesized by an easy hydrothermal method using samarium (III) nitrate hexahydrate as the doping material. The products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analysis showed that the particles were crystallized to a high degree and corresponded to the cubic CdSe phase. SEM images indicated that the size range of synthesized nanocrystallites was 50-100 nm. The photocatalytic efficiency of pure and Smdoped CdSe samples was evaluated by the degradation of C.I. Acid Orange 7 (AO7) in aqueous solution under visible light irradiation. The results showed that CdSe with Sm doping of 0.06 mole fraction led to enhanced photocatalytic activity. Color removal efficiency of 53.40% for CdSe and 90.08% for Sm_0.06Cd_0.94Se was achieved at 120 min. The Langmuir-Hinshelwood (L-H) adsorption and rate coefficients for the photocatalytic process were successfully established. Reusability tests were performed to test the stability of the photocatalysts. There was almost no loss of photocatalytic activity after four cycles of repeated use.