Dye Excitation and Surface Defects ‎Mediated Photocatalytic Behavior of ‎Vertically Aligned ZnO Nanorods

Photocatalyst for the degradation of the organic dye molecules has been investigated for the highly uniform vertically aligned ZnO nanorods grown on silicon substrates by radio frequency magnetron sputtering. An intense green luminescence located at 2.192 eV is corroborated by the singly charged oxygen vacancies and it is responsible for the visible-light-driven photocatalytic response in ZnO nanorods. The higher photocatalytic activity of organic dyes under the irradiation of visible light is enhanced due to the light absorption and better charge separation (eˉ-h^+) in vertically aligned ZnO nanorods. Further, the dye excitation is also accountable for the degradation mechanism besides surface defects under solar irradiation. Moreover, the ZnO nanorods exhibit suppressed photo corrosion and high photo-stability as evidenced by the recovery and recycling studies.