CTAB Enhanced Room-Temperature Detection of NO 2 Based on MoS 2 -Reduced Graphene Oxide Nanohybrid.

A new NO 2 nanohybrid of a gas sensor (CTAB-MoS 2 /rGO) was constructed for sensitive room-temperature detection of NO 2 by 3D molybdenum disulfide (MoS 2 ) and reduced graphene oxide (rGO), assisted with hexadecyl trimethyl ammonium bromide (CTAB). In comparison with MoS 2 and MoS 2 /rGO, the BET and SEM characterization results depicted the three-dimensional structure of the CTAB-MoS 2 /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-MoS 2 /rGO sensor performed a high response of 45.5% for 17.5 ppm NO 2 , a remarkable selectivity of NO 2 , 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-MoS 2 /rGO sensor was about two to four times that obtained for the MoS 2 /rGO sensor and the MoS 2 sensor toward 8 ppm NO 2 , which correlated with the heterojunction between MoS 2 and rGO, and the improvement in surface area and conductivity correlated with the introduction of CTAB and rGO. The excellent performance of the CTAB-MoS 2 /rGO sensor further suggested the advantage of CTAB in assisting a reliable detection of trace NO 2 and an alternative method for highly efficiently detecting NO 2 in the environment.