Synthesis, Characterization and Photocatalytic Activity of Mg‐Impregnated ZnO–SnO₂ Coupled Nanoparticles

Abstract

Abstract ZnO – SnO 2 nanoparticles were prepared by coprecipitation method; then Mg , with different molar ratios and calcination temperatures, was loaded on the coupled nanoparticles by impregnation method. The synthesized nanoparticles were characterized by X ‐ray diffraction ( XRD ), field emission scanning electron microscopy ( FESEM ), energy dispersive X ‐ray spectroscopy ( EDX ), transmission electron microscopy ( TEM ), diffuse reflectance spectroscopy (DRS), and Brunauer–Emmett–Teller ( BET ) techniques. Based on XRD results, the ZnO – SnO 2 and Mg / ZnO – SnO 2 nanoparticles were made of ZnO and SnO 2 nanocrystallites. According to DRS spectra, the band gap energy value of 3.13 and 3.18 eV were obtained for ZnO – SnO 2 and Mg / ZnO – SnO 2 nanoparticles, respectively. BET analysis revealed a Type III isotherm with a microporous structure and surface area of 32.051 and 49.065 m 2 g −1 for ZnO – SnO 2 and Mg / ZnO – SnO 2 , respectively. Also, the spherical shape of nanocrystallites was deduced from TEM and FESEM images. The photocatalytic performance of pure ZnO – SnO 2 and Mg / ZnO – SnO 2 was analyzed in the photocatalytic removal of methyl orange ( MO ). The results indicated that Mg / ZnO – SnO 2 exhibited superior photocatalytic activity to bare ZnO – SnO 2 photocatalyst due to high surface area, increased MO adsorption and larger band gap energy. Maximum photocatalytic activity of Mg / ZnO – SnO 2 nanoparticles was obtained with 0.8 mol% Mg and calcination temperature of 350°C.