AZO photocatalytic coating deposited by plasma thermal spraying with shell-type feedstock powder

Aluminum zinc oxide (AZO) was deposited on a glass substrate using plasma spraying technique. Hierarchical nanostructured morphology is observed, for the first time, in plasma spraying coatings. Nanorod and nanosphere adhere to micro spherical particle to form hierarchical structure, however, is only reported by chemical synthesis method. Through XRD and SEM analysis, it is found that the morphology of coating can improve the formation of defects greatly. After UV-A light testing, photocatalytic efficiency of coating was analyzed using UV-vis spectrometer. Combined with photoluminescence and X-ray photoelectron spectroscopy analysis, the results indicates that AZO coating is with good enhanced photocatalytic properties. This phenomenon suggests that AZO crystallites consist of multiple facets with high surface-energy planes. The measured water contact angle of about 7° indicates that AZO coating is with high hydrophilic characteristic and has very good practical applications in industry. This study thus paves a new way for environmental pollution control.