p-Co3O4 supported heterojunction Carbon Nanofibers for Ammonia gas sensor applications

Abstract

Trace level detection of gaseous ammonia is extremely important both in terms of environmental monitoring as well as health monitoring sectors. Metal oxide semiconductor, p-Co₃O₄ based nanostructures have been extensively used as gas sensing materials for the detection of a wide range of toxic gases. However, the pristine p-Co₃O₄ based sensors always face poor sensitivity and selectivity towards target gases. In order to enhance the sensitivity and selectivity of p-Co₃O₄ based sensors, carbon nanofibers can be utilized to create heterojunctions for boosting conductivity and rapid response. Herein, we report the synthesis and characterization of NH₃ gas sensor properties of p-Co₃O₄ supported heterojunction carbon nanofibers (CNF) for the detection of trace level concentration of NH₃. Structural and morphological analyses have been carried out using X-ray diffraction (XRD), Raman and Field-Emission Scanning Electron microscope (FE-SEM), etc. The evaluation of gas sensing properties of p-Co₃O₄ supported CNF nanostructures was performed, which exhibited high sensitivity for detecting NH₃ at lower working temperature and its complex sensing mechanism has been discussed. This investigation can pave the way to novel strategies for designing and fabricating low-cost, high performance NH₃ gas sensors application.