HEPES and polyol mediated solvothermal synthesis of hierarchical porous ZnO microspheres and their improved photocatalytic activity

Abstract

Uniform 3D porous hierarchical ZnO microspheres were successfully prepared via a facile solvothermal method with the assistance of 2-(4-(2-hydroxyethyl)-1-piperazinyl) ethanesulfonic acid (HEPES). The product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS) and nitrogen adsorption. HEPES acted as a directing agent in the assembling of hierarchical ZnO nanostructures. Besides, it was also found Triethylene glycol (TEG) with proper viscosity made contributions to the fabrication of porous ZnO microspheres. The synthesized hierarchical ZnO microspheres possessed largest BET surface area and ideal pore volume, as well as exhibited excellent photocatalytic activity for the photodegradation of methylene blue (MB) under UV light irradiation.