Synthesis of Au–ZnO hybrid nanostructure arrays and their enhanced photocatalytic activity

The preparation of an Au–ZnO hybrid nanostructructure array on a TCO substrate has been achieved via annealing an Au coated ZnO nanorod array in a nitrogen atmosphere. The characterization of the morphology and the structure of the Au–ZnO hybrid nanostructructure were carried out with X ray diffraction, scanning electron microscopy and transmission electron microscopy. Photoluminescence spectra give a quenched luminescent emission because of the charge separation in the prepared Au–ZnO hybrid nanostructructure. It is worth pointing out that the prepared Au–ZnO hybrid nanostructructure presents superior photocatalytic activity over ZnO nanorods in the case of the degradation procedure of methyl orange. It is found that an 8 ml methyl orange aqueous solution (2.5 ppm) could be totally degradated with 4 sheets of Au–ZnO hybrid nanostructructure (12 × 12 mm2) within 4 hours.