Ultrasound assisted template-free synthesis of Cu(OH)2 and hierarchical CuO nanowires from Cu7Cl4(OH)10·H2O

Cu(OH)2 nanowires have been synthesized by an ultrasound assisted solution route in absence of a template, using Cu7Cl4(OH)10·H2O as a precursor. Hierarchical CuO nanowires were obtained by a simple solid-state thermal transformation of these Cu(OH)2 nanowires. The products were characterized by XRD, SEM, TEM and HRTEM. The ranges of diameters and lengths of the polycrystalline CuO nanowires are ca. 20-30 nm and several micrometers, respectively. Ultrasonic time is found an important factor to morphology of the CuO products. This could be a potential efficient way for large scale fabrication of CuO nanowires with hierarchical structures. Surface photovoltage spectra of the CuO nanowires in air, NH3 and CH2Cl2 atmospheres were investigated, which demonstrates it a good photoelectric gas sensing material.