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 O ₃, CH₃CH₂OH, and H₂). The obtained data are critically discussed and interrelated with the chemical and physical properties of the nanocomposites.