Fabrication of pit-structured ZnO nanorods and their enhanced photocatalytic performance

Abstract

ZnO nanorods have been successfully prepared at low temperature (60 °C) in the presence of ammonia via a simple aqueous solution-based chemical approach. After calcination at 300 °C, many unique pitted structures are found on the surface of ZnO nanorods, although the shape and size of ZnO nanorods have almost no changes. Furthermore, the pit-structured ZnO nanorods exhibit higher photocatalytic activity for methylene blue photodegradation with a rate constant (k) of 0.01402 min⁻¹, which is about 3 times more than that of uncalcined sample. The formation of the pitted structures is presumably attributed to the decomposition of a trace amount of ZnO(NH₃)n complex implanted into ZnO crystals. In addition, a photocatalytic mechanism is proposed to explain the enhanced photocatalytic activity of the pit-structured ZnO nanorods.