effect of calcination temperature on structural, photocalalytic, and optical properties of zn-co3 o4 solid solution hydrothermally (zch) mesoporous nanoparticles

In this research, zn-co3o4 solid solution (zch) nanoparticles were synthesized by the hydrothermal method calcined at different temperatures (300, 400, 500 °c). cobalt nitrate hexahydrate (co(no3)2.6h2o) and zinc nitrate hexahydrate (zn(no₃)₂.6h₂o) were used as sources of co3o4 and zn cation. x-ray diffraction (xrd), uv-vis spectrophotometer, bet analysis, x-ray photoelectron spectroscopy (xps), field emission scanning electron microscope (fesem), and transmission electron microscope (tem) were utilized to investigate the structural, optical, surface area, photocatalytic, and morphological properties of nanoparticles. the results showed that the calcination temperature has a significant effect on the microstructure, optical, and photocatalytic activity of the samples. the crystallite size of zch nanoparticles is about 8, 11 and 14 nm, respectively, at the calcination temperatures of 300, 400 and 500 °c. the calcined solid solution sample at 400 °c (zch-400) showed higher photocatalytic degradation under visible light irradiation than the other two temperatures. the percentage of degradation of methylene blue in the presence of this sample was about 13.83% in 1 hr. increasing the calcination temperature from 300 to 500 °c led to a decrease in the band gap from 1.48 to 1.38 ev for zch samples.