Co3O4/ZnO Nanocomposites: From Plasma Synthesis to Gas Sensing Applications

Herein, we describe the design, fabrication and gas sensing tests of p-Co3O4/n-ZnO nanocomposites. Specifically, arrays of oriented ZnO nanoparticles were grown on alumina substrates by plasma enhanced 12chemical vapor deposition (PECVD) and used as templates for the subsequent PECVD of Co3O4 nanograins. Structural, morphological and compositional analyses evidenced the successful formation of pure and high-area nanocomposites with a tailored overdispersion of Co3O4 particles on ZnO and an intimate contact between the two oxides. Preliminary functional tests for the detection of flammable/toxic analytes (CH3COCH3, CH3CH2OH, NO2) indicated promising sensing responses and the possibility of discriminating between reducing and oxidizing species as a function of the operating temperature