Modified Hydrothermal Preparation of ZnO/NiO Nano-Heterojunction for Enhancement of Photocatalytic Activity

Fabrication of zinc oxide/nickel oxide (ZnO/NiO) nano-heterojunction films on glass substrates using hydrothermal and modified hydrothermal techniques was investigated. Various tools were employed for the evaluation of the structural nature and to determine the optical properties of the heterojunction. Besides, the photoactivity of the heterostructures was observed under the influence of the prepared films on the degradation of methylene blue (MB) dye. According to the X-ray diffraction and scanning electron microscopic images, the hydrothermal technique resulted in hexagonal-phase nanoplates with a thickness of 45.0-74.0 nm and nano-spherical particles of diameters of 60.6-88.0 nm. In contrast, the modified hydrothermal technique showed nanosheets of 29.0-38.0 nm thick. The photodegradation efficiency of the films was found to be strongly enhanced and reached 93% using the modified hydrothermal film. The prepared heterostructures are affordable and applicable for the degradation of contaminants in water.