Photocatalytic degradation of water pollutant dye by solid state synthesized Ni۱-xLnxSb۲O۶ (Ln=Eu, Gd, Ho and Yb) nanocomposites

Nanostructured Ni۱-xLnxSb۲O۶ (Ln = Eu, Gd, Ho and Yb) powders were synthesized via stoichiometric ۱:۲ Ni:Sb molar ratio by solid state reaction at ۸۰۰ ºC for ۸ h using Ni(NO۳)۲, Sb۲O۳, Eu۲O۳, Gd۲O۳ and Ho۲O۳ raw materials. The synthesized materials were characterized by X-ray diffraction (XRD) technique. Structural analyses were done by FullProf program employing profile matching with constant scale factor. The results showed that the patterns had a main orthorhombic NiSb۲O۶ crystal structure with P۴۲/mbc space group. The morphologies of the synthesized materials were studied by field emission scanning electron microscope (FESEM) which showed that the synthesized samples had sponge morphology. Ultraviolet – Visible (UV-Vis) spectroscopy showed that the smallest direct optical band gap energies were in the ranges of ۱.۶ to ۱.۸ eV suggesting a high efficient photocatalytic activity. Photocatalytic performance of the synthesized nanomaterials was investigated for the degradation of pollutant Malachite Green (MG) in aqueous solution under visible light condition. It was found that the optimum conditions were ۰.۰۴ mL H۲O۲, ۳۰ mg catalyst, and ۳۵ min reaction time. It was found that the synthesized NiSb۲O۶ nanocatalyst had very good efficiency in aqueous solution under the optimized conditions at the presence of visible light irradiation. The degradation yield at the optimized conditions was ۹۶ %. The optimum photocatalytic condition was used to study the performance of the other synthesized materials in the photocatalytic degradation process.

Keywords:

Dye degradation , Full Prof , Malachite green , Nanocatalyst , Solid state