Photocatalytic degradation of methylene blue using ZnO made by thermal degradation of Zn-alginate fibers

Abstract

Zinc alginate fibers (Zn-AF) were obtained by wet-spinning of sodium alginate into coagulating bath containing an aqueous zinc chloride solution. ZnO nanostructures consisting of nanofibers on the ZnO matrix were prepared from controlled thermal degradation of the as-obtained Zn-AF at 800 °C in air condition when Zn granules were added for extra ZnO source during calcination. The composition and morphology of ZnO nanostructures were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL). The SEM images show that ZnO nanofibers with diameter about 20 nm were formed on the ZnO matrix. The photocatalytic degradation experiment of methylene blue (MB) dye from aqueous solution show that ZnO nanostructures possess good photo catalytic reactivity. The performance of ZnO nanostructures can be attributed to the ZnO nanofibers which facilitate the photocatalytic degradation reaction.