The influence of Na2 SO4 on the formation of ZnO whiskers was investigated in this paper. ZnO whiskers with aspect ratios of up to 50 were synthesized by dissolving ε-Zn（OH）2 precursor in NaOH/Na2SO4 solution at room temperature, followed by aging of the resulting solution at 140 ℃ for 6 h. Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy analyses revealed that SO4^2- ions were primarily adsorbed on the （1 00） plane of the ZnO whiskers via an outer-sphere com- plex configuration （O-H……O）, thereby promoting the one-dimensional growth of ZnO whiskers along the c-axis.
