Effect of deposition method on physical and methyl orange degradation properties of ZnO nanostructures

Abstract In this research, pure ZnO thin films were effectively deposited using ultrasonic spray pyrolysis (USP) (with both milled and non-milled precursors) and Dip Coating methods to assess their photocatalytic capabilities in degrading methyl orange. The study investigated the effects of the milling process and deposition techniques on the films’ structural, morphological, and optical properties, correlating these characteristics with their degradation performance. The findings indicated that USP reduced material deposition and favored the formation of larger particles due to the elevated deposition temperatures. Structural analysis confirmed the presence of a ZnO wurtzite structure along with Zn–O functional groups, with (002) preferential growth planes and minor contributions from other planes, with crystallite size variation from 25 to 33 nm, while morphological analysis revealed smaller particle sizes in films produced via dip coating. This research elucidates how varying deposition techniques affect ZnO’s structural, morphological, optical, and photocatalytic properties, enhancing photocatalytic efficiency by altering electron–hole interactions. These results provide valuable insights for optimizing ZnO-based photocatalysts aimed at effective dye degradation, thereby supporting potential applications in environmental remediation.