Facile synthesis of oxygen vacancies mediated Co3O4 by Mn doping for high-performance ethanol sensing

The detection of volatile organic compounds (VOCs) at extremely low concentrations holds significant importance in industry and daily life. In this study, Mn-doped Co3O4 materials with a mesoporous structure and oxygen vacancies were synthesized through manual grinding and calcination treatment. The structural characterization measurements showed that Mn doping restrained the crystal growth of the cobaltous oxides which was beneficial for the mesoporous structure, and appropriate oxygen vacancies. The 0.2Mn–Co3O4 sensor operated at the optimum operating temperature of 260 °C, showed a higher response (32.0) to 30 ppm ethanol, which was about 5.81 times as much as that of the pure Co3O4 (5.5). Additionally, to ethanol the 0.2Mn–Co3O4 sensor manifested ultra-low detection limit (11.6 ppb), fast response/recovery time (25/15 s) and superior stability. These exceptional performances may be attributed to the synergistic effect of mesoporous structure formation and appropriate oxygen vacancy concentration. Consequently, the Mn-doped Co3O4 sensor has great potential for detecting low-concentration ethanol in practical applications. [Display omitted] •Mn doped Co3O4 samples have more specific surface area and oxygen vacancies.•The 0.2Mn–Co3O4 sensor showed more excellent gas sensitivity to ethanol gas.•0.2Mn–Co3O4 sensor exhibited ultra-low detection limit for ethanol gas.•The change of carriers at high temperatures leads to samples xMn-Co3O4 showing an abnormal n-type gas-sensing response.