Ultrasonic assisted synthesis of ZnO nanoflakes and photocatalytic activity evaluation for the degradation of methyl orange

Abstract

In the present investigation, ZnO nanoflakes was prepared via sonochemical synthesis route. Effect of ultrasonic treatment time was studied based on structural, morphological and optical properties. X-ray diffraction (XRD) reveals the formation of wurtzite hexagonal crystalline structure of ZnO nanoflakes. Ultrasonic treatments affected the crystallite size and the density of dislocation, which is due to increased nucleation and growth rates of nanoflakes. The samples synthesized at 40–50 min ultrasonic treatment showed a strong absorption band at 605 and 650 (cm−1) versus other treatments, which is an indication of 2D nanostructure (nanoflakes). FE-SEM analysis further confirms the formation of 2D nanostructures of the ZnO. The composition and purity was confirmed by the energy dispersive X-ray (EDX) analysis, which displays the occurrence of Zn and O elements in the sample. Photocatalytic activity (PCA) of ZnO nanoflakes was studied for methyl orange (MO) dye degradation under UV light exposure and up to 93.13 % dye degradation is achieved within 90 min. Effect of various parameters (dye concentration, mass of photocatalytic material) and kinetic study was also performed. Results revealed that the ultrasonic treatment affected the optical and photocatalytic properties of the of ZnO nanoflakes, which could be employed for the remediation of dyes in textile effluents.

Keywords

• ZnO nanoflakes
• Ultrasonic treatment
• Optical
• Structural
• Photocatalysis
• Methyl orange