Factors impacted on anisotropic photocatalytic oxidization activity of ZnO: Surface band bending, surface free energy and surface conductance

• ZnO oriented thin film samples were prepared by pulsed laser deposition.
• The films show anisotropy on photocatalytic oxidization activity.
• Important factors are surface band bending, surface energy and surface conductance.

ZnO thin films with three low-indexed crystal planes were prepared by pulsed laser deposition and investigated for photocatalytic activity. The results revealed that the ZnO showed anisotropic photocatalytic activity and the order of activity for methylene orange and dichlorophene decomposition was (0 0 1) < (1 0 0) < (1 1 0). The highest photocatalytic activity of the (1 1 0) crystal plane orientated sample was ascribed to the more upward surface band bending, higher surface free energy and larger surface conductance. These results implied that synthesizing the (1 1 0) facet exposed ZnO sample would be an effective approach for the obtainment of higher activity.

ZnO shows anisotropic photocatalytic activity and the order of activity for methylene orange and dichlorophene decomposition is (0 0 1) < (1 0 0) < (1 1 0). The highest photocatalytic activity of the (1 1 0) crystal plane orientated sample is ascribed to the more upward surface band bending, higher surface free energy and larger surface conductance.Figure optionsDownload as PowerPoint slide