Magnesium oxide nanoparticles for effective photocatalytic degradation of methyl red dye in aqueous solutions: Optimization studies using response surface methodology

Abstract

In this present research, magnesium oxide nanoparticles (n-MgO) were prepared using co-precipitation method and assessed for photo-chemical degradation of methyl red (MR) in presence of UV light. The X-Ray Diffraction (XRD) and scanning electron microscopy (SEM) for n-MgO show spherical crystalline particles with average crystallite size of 13.89 nm. The Tauc plot through UV spectra shows the band gap of n-MgO is estimated as 4.6 eV. Response surface methodology (RSM) using the central composite design (CCD) was used to design the experiments and optimize the process and the effectiveness of methyl red destruction was obtained as 97.08% at the optimal conditions obtained by CCD. The methyl red degradation kinetics fitted with first order kinetic model. The recovery process of the MgO photo catalyst is easier and reusability studies shows that the catalyst can be reused for decolourization of dye with slight reduction in efficiency.