Synthesis and photocatalytic study of Zn0.90Co0.10O and Zn0.90Co0.05M0.05O (M = Ca, Ba, Cr, Pb) nanocrystals: structural, optical and electrical investigations

Abstract Novel Zn0.90Co0.10O and Zn0.90Co0.05M0.05O (M = Ca, Ba, Cr, Pb) nanocrystals were synthesized by co-precipitation method and studied its structural, optical and electrical properties along with their photocatalytic activity. The XRD confirmed that Ca, Ba, Cr, and Pb have been incorporated without modifying ZnO hexagonal wurtzite structure. The microstructural parameters were calculated using Scherrer, W–H, and SSP methods. FTIR confirmed the existence of Zn–O vibrational modes. UV–vis spectra used to calculate the energy bandgap by using Tauc’s plot, Energy equation, Vegard’s law, and Derivative method. Optical parameters such as Urbach energy, refractive index, dielectric constant, extinction coefficient and optical conductivity were also studied. The IV measurements demonstrated that electrical conductivity was increased significantly by co-doping. The photocatalytic activity for the decolorization of methylene blue (MB) and methyl orange (MO) dyes under sunlight revealed the highest degradation efficiency for co-doped nanocrystals against MB as compared to MO in 100 min illumination. The grown nanocrystals are propitious sunlight driven photocatalyst to eradicate organic toxins.