CTAB Enhanced Room-Temperature Detection of NO₂ Based on MoS₂-Reduced Graphene Oxide Nanohybrid

A new NO₂ nanohybrid of a gas sensor (CTAB-MoS₂/rGO) was constructed for sensitive room-temperature detection of NO₂ by 3D molybdenum disulfide (MoS₂) and reduced graphene oxide (rGO), assisted with hexadecyl trimethyl ammonium bromide (CTAB). In comparison with MoS₂ and MoS₂/rGO, the BET and SEM characterization results depicted the three-dimensional structure of the CTAB-MoS₂/rGO nanohybrid, which possessed a larger specific surface area to provide more active reaction sites to boost its gas-sensing performance. Observations of the gas-sensing properties indicated that the CTAB-MoS₂/rGO sensor performed a high response of 45.5% for 17.5 ppm NO₂, a remarkable selectivity of NO₂, an ultra-low detection limit of 26.55 ppb and long-term stability for a 30-day measurement. In addition, the response obtained for the CTAB-MoS₂/rGO sensor was about two to four times that obtained for the MoS₂/rGO sensor and the MoS₂ sensor toward 8 ppm NO₂, which correlated with the heterojunction between MoS₂ and rGO, and the improvement in surface area and conductivity correlated with the introduction of CTAB and rGO. The excellent performance of the CTAB-MoS₂/rGO sensor further suggested the advantage of CTAB in assisting a reliable detection of trace NO₂ and an alternative method for highly efficiently detecting NO₂ in the environment.