Nanostructured zinc oxide (ZnO), as a semiconductor, is used as an alternative to TiO2 for the construction of hybrid solar cells. We studied two different nanostructures-nanowires (NWs) and hedgehog-like needle-clusters prepared by hydrothermal growth method. The morphological parameters were examined by scanning electron microscopy (SEM). The X-ray diffraction (XRD) data for both samples confirmed wurtzite structure. The surface chemistry was investigated by X-ray photoelectron spectroscopy (XPS) and paramagnetic defects were studied by electron paramagnetic resonance (EPR) technique. This analysis confirmed that both types nanostructures of ZnO achieve comparable quality in terms of structure and sample purity.