Controllable preparation of ultralong ZnO nanowire arrays based on microfluidics

In this paper, hydrothermal method is combined with microfluidic technology to fabricate a microfluidic chip for the controllable preparation of ultralong ZnO nanowire arrays (ZNAs). First, the existing technical proposals and experimental parameters are optimized. Then, the seed solution is injected into the microchannel of microfluidic chip to form a dense ZnO seed layer. Finally, the growth solution is injected to prepare ZNAs on the surface of the ZnO seed layer in the microchannel. X-ray diffraction result shows that the as-prepared ZNAs possess high crystallinity and exhibit a preferred growth orientation along the c-axis. In addition, scanning electron microscopy images show that the length of ZNA reaches up to 46 μm by appropriately controlling the growth temperature (90 C), flow rate (15 μL/min) and growth time (10 h), which effectively increases the growth rate of ZNA.