ZnO conjugated graphene: An efficient sunlight driven photocatalyst for degradation of organic dyes

A robust, sunlight driven photocatalyst was produced by deposition of ZnO nanotrapezoids over the surface of graphene (GR.) nanosheets. Thus obtained GR-ZnO nanocomposite was capable in complete degradation of industrially versatile used different categorized organic dyes viz., azo (methyl orange), thiazin (methylene blue) and fluorescein based dyes (Rhodamine B) under irradiation to natural sunlight. The photocatalytic activity of GR-ZnO nanocomposite was enormously enhanced than its component constituents, graphene nanosheets and ZnO nanotrapezoids. The heterojunctioned hybrid structure generated by successful conjugation of graphene nanosheets and ZnO nanotrapezoids provided excellent photocatalytic activity to GR-ZnO nanocomposite. The photocatalytic activity of GR-ZnO nanocomposite was evaluated in detail by kinetic analysis using Langmuir-Hinshelwood (L-H) model. By the catalytic action of GR-ZnO nanocomposite, an elevated degradation was found with anionic dye methyl orange compared to cationic dyes, methylene blue and Rhodamine B. In addition to its admirable photocatalytic activity, GR-ZnO nanocomposite possessed the excellent structural and photocorrosive stability, needed for practical application of a photocatalyst.