Enhancing the Photo and Biomedical Activity of ZnO by Incorporation with Zinc Silicate Nanocomposites

Abstract

Highly active and non-toxic ZnO incorporated with zinc silicate (zinc silicate/ZnO) nanocomposites are synthesized via a simple and low-cost hydrothermal method followed by heat treatment. Different molar ratios from Si to Zn [1:20], [1:10], [1:8] and [1:6] are used to prepare different zinc silicate/ZnO nano composite materials which are assigned to ZS1, ZS2, ZS3 and ZS4 samples, respectively. The effect of calcination times and temperatures have been investigated on the crystallographic and morphological properties of the synthesized nano composite materials. The XRD analysis show that at very low molar ratios, zincite (ZnO) is the most predominant phase. However, at higher molar ratios, there are two phases coexist; hemimorphite (Zn4Si4O7) and zincite. The TEM images show a uniform nanoplate-like shaped morphology from ZnO with well dispersed Zn2SiO4 nanoparticles. The SBET is remarkably increased from 18.14 to 176.5 m2.g−1 by calcination up to 400 °C and then decreased to 72.2 m2. g−1 by further increasing in the calcinations temp up to 1,000 °C. The bio and photocatalytic activities of the composite nanomaterials have been investigated. Compared with the pure ZnO, the nano composites have been demonstrated as better photocatalysts for the degradation of Levafex golden yellow (LGY) dye as a model of organic dye pollutant under simulated sunlight irradiation. Moreover, the nano composites were evidenced to possess better and non-toxic antitumor activity towards hepatocellular carcinoma cell lines with (IC50 = 11.2 μg.ml−1 and LD50 ˃ 50 mg. Kg−1).