Synthesis of pure and doped SnO2 and NiO nanoparticles and evaluation of their photocatalytic activity

This paper presents a comparative experimental study between sol-gel and sonochemical approaches for the synthesis of SnO2 and NiO nanoparticles. In addition, the doping effect on the structural, optical properties and the photocatalytic activity of the synthesized oxides was studied. The XRD results revealed the high purity of the prepared oxides and the well incorporation of the dopant elements into the host structure. Morphological characterization by HR-TEM showed ultrafine nanoparticles with an average size <10 nm for the oxides calcined at 250 degrees C. The particle size increased upon calcination reaching about 30-40 nm for the samples calcined at 750 degrees C. The EDX results of the doped samples ensured the existence of the dopant elements without any impurities. Diffuse reflectance spectroscopy UV-DR results of the doubly doped tin oxide Sn0.094Ti0.03Ni0.03O2 and nickel oxide Ni0.094Ti0.03Sn0.03O exhibited lower band gap energies 3.24 eV and 3.27 eV, respectively, than that of their corresponding pure oxides. The fluorescence probe method and the photodegradation of Coomassie Brilliant Blue dye R (CBBR) showed higher photodegradation rate constants over the oxides prepared by sonochemical than sol-gel routes. The photocatalytic activity process using five real industrial wastewater samples was explored and the results revealed that these oxides could be feasible candidates for the photodegradation of organic pollutants.

Automated summary

This study compares the synthesis of SnO2 and NiO nanoparticles using sol-gel and sonochemical methods, and investigates the doping effect on the properties of the synthesized oxides. The results showed that the oxides prepared by sonochemical route exhibited higher photocatalytic activity.