Plasma-assisted synthesis of p-Co3O4/n-ZnO Nanocomposites for Gas Sensors

The present contribution is focused on the design and characterization of p-Co3O4/n-ZnO nanocomposites as gas sensors for the detection of flammable/toxic analytes. A two-step Plasma Assisted-Chemical Vapor Deposition (PA-CVD) process was used to develop the target systems. The synthetic approach consisted in the initial deposition of c-axis oriented ZnO on polycrystalline alumina substrates, followed by the over-dispersion of tailored Co3O4 amounts. A multi-technique analysis, involving Glancing Incidence X-ray Diffraction (GIXRD), Field Emission-Secondary Electron Microscopy (FE-SEM), and X-ray Photoelectron Spectroscopy (XPS), evidenced the successful deposition of Co3O4 particles on the ZnO matrix and the absence of Co-Zn-O ternary phases. The obtained composite materials displayed attractive properties as gas sensors for acetone, ethanol and nitrogen dioxide.