Photocatalytic oxidation of NO_{x gases using ZnO with superstructure by a low temperature soft solution process

Single phase of crystalline ZnO with controllable morphologies, including spindle–like, sunflower–like, dandelion–like and disk–like structures samples, have been successfully synthesised via a simple and effective low–temperature approach in a mixed solution of zinc nitrate and hexamethylenetetramine, with and without 2–aminoethanol as an accelerant. The ZnO crystal with different morphology can be obtained by simply varying the additive and reaction time. The samples were characterised by XRD, SEM, DRS and BET. The prepared ZnO with the sunflower–like superstructure showed excellent photocatalytic activity for the decomposition of NOx gas under UV light irradiation, being superior to that of a standard TiO2 (Aeroxide P25) powder.