Modified sol-gel technique for the synthesis of pure MgO and ZnO nanoparticles to study structural and optical properties for optoelectronic applications

Abstract

Pure MgO and ZnO nanoparticles were synthesized using the modified sol–gel technique at optimized calcination temperatures of 200 °C and 300 °C for 2 h. The structural and optical properties were characterized using X, -ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–VIS spectroscopy, Energy dispersive X-ray spectroscopy (EDAX), and scanning electron microscopy (SEM). The XRD analysis confirms that MgO and ZnO are in cubic and hexagonal Wurtzite phase and are in nanosize, with major diffraction peaks of MgO at (200), (220), and for ZnO nanoparticles at (100), (002), and (101), respectively. The average crystallite size of MgO and ZnO nanoparticles was calculated by using the Debye-Scherrer formula, which is found to be 16 nm for MgO and 20 nm for ZnO NP’s. Particle sizes of 30 to 50 nm for MgO and 40 to 80 nm for ZnO nanoparticles were confirmed by SEM results. From UV–Visible spectroscopy, the excitation wavelengths of MgO and ZnO were 322 nm and 375 nm, respectively. The optical band gap is found to be 5.4 eV for MgO and 5.2 eV for ZnO, which is determined using the Tauc Plot equation. These results are suitable for advanced optoelectronic and photonic applications.