Preparation, characterization and photocatalytic activity of hexagonal ZnO nanoparticles

Hexagonal zinc oxide (ZnO) nanoparticles were synthesized via thermal decomposition of precursors prepared from carboxylic acids, such as oxalic, citric or tartaric acids, using a promising method. The as-prepared precursors were studied using thermal gravimetric analysis (TGA). The materials resulting from the heat treatment were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Their specific surface areas were determined using the BET method to be approximately 20 m2/g. The particle size was determined to be 40 nm based on TEM and 25 nm calculated from XRD. Therefore, the crystallite dimensions were confirmed to be on the nanoscale. All of these zinc oxide samples have exhibited very good efficiency for photodegradation of methylene blue (MB), which was used as a standard pollutant, under UV light irradiation.