Investigations on growth and hydrogen gas sensing property of ZnO nanowires prepared by hydrothermal growth

Very narrow ZnO nanowires are synthesized on the sputtered ZnO seed layer by hydrothermal growth method. Varying the growth parameters we can obtain several features of ZnO nanowire. The nanowires with a diameter of about 15 nm and with a length longer than 5 ¿m are grown, which are much narrower than ZnO nanowires grown by chemical vapor deposition. The underlying ZnO seed layer enhanced the nucleation of ZnO nanowire during the followed ZnO synthesis by hydrothermal growth but without the seed layer, ZnO grown randomly as a rod shape. The molar ratio of the source is critical to the shape of the ZnO nanowire. Crystal orientation of ZnO nanowire is investigated by X-ray ¿-2¿ diffraction and microstructure of the ZnO nanowire is examined by transmission electron microscopy. Hydrogen-gas sensing property is measured and compared from the synthesized ZnO nanowires.