Facile fabrication of hydrophobic ZnO nanostructured nickel microtubes through pulse electrodeposition as promising photocatalyst for wastewater remediation

This study explores pulse electrodeposition as a fabrication technique for manufacturing ZnO nanostructures on Nickel tubular thin films to be used as catalysts for degradation of harmful dyes in waste water. Nanostructures of diverse morphology such as nanodiscs, nanosheets, nanorods etc. have been developed on the electroformed nickel tubes by varying the parameters of the electrodeposition process. Hexamethylenetetramine (HMTA) ligand and appropriate current density has led to the growth of well aligned ZnO nanorods on the nickel substrate. The hydrophobicity of the said functional substrates was investigated through wettability studies and it was found to be approaching superhydrophobic behaviour with a contact angle of 142?degrees. An analytical model has also been developed to predict the contact angle from the droplet spread on the metallic tubular surface with good accuracy. The photocatalytic capability was assessed by using the most hydrophobic substrate having ZnO nanorods for degradation of textile dyes. The larger surface area is responsible for higher charge separation. Hence, nanorod like structures obtained through this novel fabrication approach have played a significant role behind the enhanced photocatalytic degradation efficiency of 91.21% within 60 min as compared to other reported works.