The improvement of the band gap energy and antibacterial activities of CeO2/ZnO nanocomposites prepared by high energy ball milling

Abstract

CeO2/ZnO nanocomposites were prepared by mechanical milling. The crystal structure, morphology and optical properties were characterized by X-ray diffraction method, scanning electron microscopy and UV-vis spectrophotometer, respectively. The antibacterial activity was tested by a broth microdilution method to obtain the minimum inhibitory concentrations (MIC). The crystallite size decreased from 29.78 to 20.45 nm whereas the micro-strain increased from 0.0814 to 0.1202 when the CeO2 powders were loaded from 0 to 10 mol%. The widest optical band gap of 3.135 eV was obtained from 5 mol% CeO2/ZnO nanocomposite. The antibacterial activity was improved as a function of the CeO2 loading contents. The best antibacterial activity was obtained from 10 mol%CeO2/ZnO nanocomposites that inhibited towards S. aureus and E. coli with MIC values of 0.78 mg/mL and 3.125 mg/mL, respectively.