Aligned ultralong ZnO nanobelts and their enhanced field emission

A new technique for the growth of aligned ultralong ZnO nanobelts on metal substrates in a one-step process via molten-salt-assisted template-free thermal evaporation was analyzed. These ultralong nanobelts show enhanced field emission, the as-grown ZnO nanobelts on the Au substrates indicates that the nanobelts can grow to several millimeters in length. The ZnO nanobelts were found to be transparent by using a top-view optical microscope. A higher-magnification optical microscopy image of the side-view indicates nominal, though imperfect alignment. Field-emission scanning electron microscopy images show the as-grown ZnO nanobelts under different magnifications. The new approach was designed by combining a general molten-salt process which is usually used to prepare micrometer-scale ceramic powders. The main point of this new approach was the evaporation of Zn metal powder in a liquid environment of molten sodium chloride salt.