Alkali/zinc-activated fly ash nanocomposites for dye removal and antibacterial applications.

[Display omitted] • Alkali/zinc-activated fly ash nanocomposites were prepared using hydrothermal method. • Decoration with ZnO favorably enhanced the surface area and charge of nanocomposites. • Negative surface charge plays a major role in methylene blue adsorption. • The prepared nanocomposites have high adsorption and antibacterial activities. Fly ash (FA), obtained as waste materials from industrial power plants, is generated in large quantities and low recycling. In this study, re-generation of waste FA as cost-effective materials with adsorbent and antibacterial applications was assessed. Alkaline/zinc-activated fly ash nanocomposite (A-FA/Zn) was prepared using one-pot hydrothermal technique. Those nanocomposites are characterized by high surface area and negatively surface charge, which are important influences contributing to an enhancement in adsorption capacity via increase in the number of adsorptive sites and electrostatic interaction between dye molecules-nanocomposites. Additionally, the presence of Zn ions in the prepared nanocomposites represents a key advantage with respect to enhancing antibacterial activity. The feasibility of further enhancing adsorption and antibacterial mechanisms was also examined. It is anticipated that the findings of this study will provide useful information with respect to the development of simple, eco-friendly and low-cost A-FA/Zn with multifunctional applications as organic dye removal and antibacterial purposes. [ABSTRACT FROM AUTHOR]