Atmospheric Pressure Plasma Coating of Bismuth Oxide Circular Droplets

Abstract

In this study, bismuth oxide powder (Bi2O3) was deposited by an atmospheric pressure plasma jet onto borosilicate glass. The layer produced through this method is to be used as a photo catalyst in later applications. The deposited coating was analyzed by X-ray diffraction (XRD) to determine the crystal structure, and X-ray photoelectron spectroscopy (XPS) to analyze the chemical state. The results showed a change in crystal and chemical structure during the deposition process. The morphological properties of the layer were examined with scanning electron microscopy (SEM) and laser scanning microscopy (LSM). The band gap structure of the coating was investigated by UV-Vis spectroscopy. The layer produced by the plasma spraying process consisted of circular multi-phase bismuth oxide droplets (monoclinic Bi2O3 and tetragonal Bi2O2.33), showing a direct band gap of Eg = 2.72 eV, which allows their use as a photocatalyst.