Research Progress in Preparation and Applications of ZnO Nanowire/rod Arrays by Hydrothermal Method

The quality of zinc oxide (ZnO) nanowire/rod arrays determines the performance of the constructed photoelectric devices. In order to prepare high-quality ZnO nanowire/rod arrays with greater surface to volume ratio, better verticality and separate roots, a brief summary has been made about the research progress of the controllable preparation of ZnO nanowire/rod arrays using two-step hydrothermal method in this paper. Moreover, how the seed layer, growth solution and preparation method influence their morphology has been discussed respectively, and the mechanisms of ammonia, hexamethylenetetramine and polyethyleneimine in promoting the growth of nanowire/rod arrays have been particularly analyzed. At the same time, the method of controllable preparation of ZnO nanowire arrays based on microfluidic technique has been put forward, which can improve the growth efficiency of nanowire arrays. Finally, an introduction has been made about how the morphology of ZnO nanowire/rod arrays plays an important role in improving the performance of dye-sensitized solar cells, nanogenerators, gas sensors and field emission devices, and an outlook of future development trend of two-step hydrothermal method in preparing ZnO nanowire/rod arrays is also provided.