MOF-derived Au-loaded Co3O4 porous hollow nanocages for acetone detection

Abstract

Metal-organic-framework-(MOF)-derived nanostructured metal oxides have received great research interest due to their well-defined structure, high surface area, and excellent gas accessibility. In this work, ZIF-67 was utilized as a sacrificial template to synthesize pure and Au-loaded Co3O4 porous hollow nanocages. Acetone-sensing performance of the prepared pure Co3O4 and Au-loaded composites was systematically examined. For the optimal sensor (Au/Co3O4-4), a large response of 14.5 to 100 ppm acetone and a low limit of detection of 1 ppm at the optimum working temperature of 190 °C were achieved. A sensor array composed of the pure Co3O4 and Au/Co3O4-4 sensor was assembled, in conjunction with principal component analysis (PCA) method, to distinguish acetone from other interfering gases including ethanol. The mechanism of improved acetone-sensing performance was discussed in gas accessibility of nanocages and catalytic promotion of Au.