CuO/ZnO Nanocomposite Gas Sensors Developed by a Plasma-Assisted Route

CuO/ZnO nanocomposites were synthesized on Al2O3 substrates by a hybrid plasma-assisted approach, combining the initial growth of ZnO columnar arrays by plasma-enhanced chemical vapor deposition (PE-CVD) and subsequent radio frequency (RF) sputtering of copper, followed by final annealing in air. Chemical, morphological, and structural analyses revealed the formation of high-purity nanosystems, characterized by a controllable dispersion of CuO particles into ZnO matrices. The high surface-to-volume ratio of the obtained materials, along with intimate CuO/ZnO intermixing, resulted in the efficient detection of various oxidizing and reducing gases (such as O3, CH3CH2OH, and H2). The obtained data are critically discussed and interrelated with the chemical and physical properties of the nanocomposites.