Cost-effective and eco-friendly dye degradation by enzyme-powered ZnO nanomaterial: effect of process temperature

Employing enzymes as co-catalysts with semiconducting oxides is one of the cost-effective and nature-friendly ways for photocatalytic decomposition of toxic organic dye molecules. In the present study, enzyme-powered zinc oxide nanomaterial was prepared using vermiwash derived from the earthworm ( Endrilus eugeniae ) culturing unit. Two sets of samples were prepared via a simple soft-chemical method by applying heat (i) during the stirring stage of synthesis and (ii) as post-synthesis heat treatment. The effect of this heat treatment on the photocatalytic efficiency of the synthesized nanoproduct has been studied. The study on the activity of enzymes present in the nanoproduct, structural studies through X-ray diffraction, scanning electron microscopy, transmission electron microscopy and photocatalytic degradation studies are fitly correlated among them to address the observed enhancement in the photocatalytic activity. The results provide strong evidence to support the potential use of vermiwash for synthesising nano-sized photocatalysts that can be used to treat toxic organic pollutants, such as methylene blue.