The precipitation synthesis of zinc (II) oxide for photocatalytic degradation of anionic and cationic dyes

The method of zinc (II) oxide synthesis by precipitation of zinc (II) acetate precursor has been developed. With the method of scanning electron microscopy, it was found that ZnO particles have a size of less than 100 nm. It contains a pure phase of zinc (II) oxide of the hexagonal syngony of the wurtzite type, which was proved by the X-ray diffraction method. The absorption spectrum of suspension of the obtained zinc (II) oxide powder was obtained and the optical bandgap was calculated by the Kubelka–Munk formula. The synthesized zinc (II) oxide is a well-crystallized solid material with semiconductor properties and a clear bandgap, starting at 3.1 eV. The resulting zinc (II) oxide has a BET surface area of 22 m2/g, as a result of which, its total porosity and micropore volume are small: 0.13 cm3/g and 0.06 cm3/g, respectively. It confirms that the obtained ZnO is a well-crystallized, non-porous material. The photocatalytic activity of the synthesized zinc (II) oxide is very high towards the dyes of both, anionic and cationic natures. The experimentally achieved values of the photocatalytic decomposition degree of the studied dyes indicate to an ambiguous influence of the model photocatalytic process organization on the efficiency of ZnO.