CNT functionalized, Graphitic carbon nitride (g-C3N3) mediated Co3O4 nanocomposite material: Fabrication, Characterization, and utilization for Flammable gas detection for environmental remediation

The research portrayed here is deals with the synthesis of bare Co₃O₄ material and carbon nanotubes modified g-C₃N₄- Co₃O₄ material. Initially, bare cobalt oxide was synthesized by co-precipitation technique. The Co₃O₄ was utilized for preparing CNT-g-C₃N₄-Co₃O₄ nanocomposite material by heat and beat method. These both solid materials viz. Co₃O₄ and CNT-g-C₃N₄-Co₃O₄ were utilized for designing the gas sensor by means of standard screen printing method. Both these fabricated materials were analyzed by several material characterization techniques. From XRD study the structural data of both these materials was fetched. From XRD analysis the cubic lattice of Co₃O₄ was confirmed. The scanning electron microscopy was studied for both these materials to investigate the topographic and surface characteristics. While, the elemental composition was these materials was investigated by EDS analysis. The crystal lattice and nature of the prepared material (amorphous or crystalline) was known from HR-TEM analysis. The amorphous nature of CNT-g-C₃N₄-Co₃O₄ was confirmed from SAED pattern. The BET was investigated for surface area and porosity. The magnetic characteristics of these materials were confirmed by VSM analysis. The photo lithographically fabricated sensor materials were tested for gas sensing study of several toxic, flammable gases CO, NO₂, LPG and petrol vapors. In addition to that the materials were also utilized for humidity assay investigation. The useful gas detection characteristics were investigated thoroughly which includes the response of a sensor, specific selectivity towards tested gases, reusability, and comparison of the sensor, effect of gas concentration and effect of temperature was investigated for both these sensors. From overall investigation it was observed that the g-C₃N₄- Co₃O₄ is excellent sensor towards carbon monoxide and volatile petrol gas at moderate concentration and optimum thermal conditions.