Reduced graphene oxide with La@Co₃O₄ and La@CdO nanocomposite based sensors: synthesis, characterization and NO₂ sensing properties

In the present study, we report fabrication of La@Co₃O₄ and La@CdO with rGO as new materials for NO₂ sensing at a temperature range of 30–90 °C. The nanocomposites were characterized using various characterization tools like FTIR, Powder XRD and SEM to determine the composition and morphology of the nanocomposite sensors. The sensing properties such as sensor response, response time and recovery time were measured. The obtained results exhibited that rGO/La@Co₃O₄ showed a response of 2.9 while rGO /La@CdO is 2.4 at 50 °C. The sensor exhibited high selectivity to NO₂, which is explained by a higher affinity for NO₂ compared to other environmental pollutant gases like Cl₂, NO, H₂O and CO. The sensing mechanism was explained by the synergistic effect of reduced graphene with La@Co₃O₄ and La@CdO.