Highly oriented ZnS nanorod arrays with controlled diameters: solvothermal synthesis, size-dependent band-edge emission and photocatalytic properties.

High quality ZnS nanorod arrays with controlled diameters were directly grown on Zn substrate via a facile solvothermal reaction of metallic Zn with thiourea in hydrazine hydrate at 180 degrees C. The control over the diameters of the nanorods was achieved by adjusting the reaction time. The as-prepared ZnS nanorods were single-crystalline with a hexagonal wurtzite structure and grown along the [0001] direction. The role of hydrazine hydrate in the formation of ZnS nanorod arrays was investigated, and a possible mechanism was also proposed. The photoluminescence and photocatalytic activities of the as prepared ZnS nanorod arrays were studied. It was found that the ZnS nanorod arrays exhibit the size-dependent band edge emission and photocatalytic activities in the degradation of acid scarlet, and have potential applications in the fields of nanolaser and other photoelectronic devices as well as pollutant treatment.