Unlocking superior acetone sensitivity with Co₃O₄/ZnO nanowire innovations

Herein, we present an innovative design utilizing two metal oxides, ZnO and Co3O4, which exhibit exceptional gas response and outstanding selectivity. The proposed p-Co3O4/n-ZnO composite nanowires are prepared by insitu thermal oxidation and evaporation at a temperature of 800 degrees C. The successful growth of these Co3O4/ZnO composite nanowires has been confirmed through detailed morphological, compositional, and structural analyses. These nanowires feature a unique architecture with Co3O4 at the root, ZnO forming the body, and Pt and Co3O4 at the tip. Preliminary gas sensing tests reveal promising acetone (C3H6O) detection capabilities, which are attributed to the presence Pt nanoparticles and the Co3O4 segment at the tip. Moreover, the formation of p-n heterojunctions, combined with the synergistic gas sensing effect, and the catalytic activity, significantly enhances the response of the sensor. The sensors demonstrate an impressive gas response (Delta G/G) of 5780 towards 50 ppm of C3H6O at 250 degrees C in 40 %RH air, with an estimated detection limit of 0.4 ppm. The underlying sensing mechanisms are thoroughly analyzed, providing insights into how the unique design leads to superior gas sensing performance.