Bio-inspired Ag@fishscale: a recyclable photocatalyst for organic pollutant degradation

The present study explores the possibility of developing an environmentally sustainable, easily recyclable biocatalyst using discarded fish scales. The fish scales were treated with silver nitrate solution at ambient temperature, resulting in the adsorption and reduction of silver ions, forming crystalline silver nanoparticles (Ag NPs) and micrometer-scale silver phosphate (Ag 3 PO 4 ) crystals on the fish scale's surface. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show a relatively uniform distribution of Ag-rich particles on the supporting surface, with TEM also revealing the texture of apatite nanocrystals of the fish scale. We assessed the photocatalytic potential of the composite (Ag@fishscale) by using an organic dye (methylene blue) as a model compound for water contaminants. The results demonstrate that the Ag@fishscale catalyst exhibits a degrading effectiveness of around 55% for methylene blue under UV light irradiation over a duration of 4 h. The Ag@fishscale photocatalyst can be reused and may be utilised efficiently in the photodegradation of organic dyes found in industrial effluents.