ZnO codoped with Si and Mn – Preparation, characterization and photocatalytic reduction of hazardous chromium (VI) by the codoped ZnO

Zinc oxide-silicon dioxide nanocomposite, doped with manganese, was blended by chemical co-precipitation mode. Its structural properties, surface morphology, and optical properties had been probed by X-ray diffractometer, field emission scanning electron microscope then ultraviolet–visible spectrophotometer. The dependence of properties on manganese concentrations was investigated. It was observed that the structural properties, band gap and photocatalytic properties are influenced by the amount of manganese ions. Chromium (VI) is hemotoxic, genotoxic besides carcinogenic. The doped nanocomposite was tested for photocatalytic conversion of hazardous chromium (VI) to chromium (III) under ultraviolet besides sunlight. Best result for chromium reduction was achieved in 30 min with 10 % manganese doped nanocomposite under sunlight. The prepared nanocomposite is more active under sunlight than under ultraviolet.