Hydrothermal synthesis of ZnO nanobelts and gas sensitivity property

The ZnO nanobelts were synthesized by a hydrothermal method. The XRD spectrum indicates that the sample is wurtzite (hexagonal) structured ZnO with lattice constants of a=3.249Å, c=5.206Å. SEM and TEM images show the nanobelts to have lengths of 10–20 μm, widths of 50–500 nm, thicknesses of about 30–60 nm, and growth direction of [0001]. Gas sensitivity experiments on ZnO nanobelts were carried out under different temperatures. The results indicated high sensitivities with an operating temperature of only 220 ∘C for the oxidative gas O2, and 305 ∘C for the gas N2. The mechanism of gas sensitive effects is analyzed in detail.