Biopolymer starch mediated synthetic route of multi-spheres and donut ZnO structures

Abstract

A starch-assisted synthetic methodology of multispheres ZnO-starch biocomposites was developed. An additional thermal processing of the ZnO-starch composites induces the formation of ZnO with donut-like morphology. The synthesis of single-phase zinc oxide with a spherical morphology is conditioned by the presence of starch, which acts as template, stabilizing/capping agent. The synthesized structures present significant photocatalytic activities; a total phenol mineralization is attained with the donut-like ZnO photocatalyst under visible light irradiation, due to a cumulative effect of the its relatively large specific surface area, high crystallinity and favorable combination of defects for band narrowing, which together permit an enhanced utilization rate of the light.

Keywords: Multi-spheres and donut structure; Optical properties, Visible-photocatalyst; Starch; ZnO.