Heterogeneous Co3O4/AgO nanorods for conductometric triethylamine sensing at 90 °C

To achieve room or low temperature gas sensitivity with low power consumption has been a challenging task for metal oxide semiconductor gas sensors. In this work, heterogeneous Co 3 O 4 /AgO nanorods are synthesized by wet-chemical method. The structural and compositional characterizations show that AgO nanoparticles are highly dispersed on the surface of Co 3 O 4 nanorods. It is found that the AgO nanoparticles can trigger both catalytic and electronic sensitization that lead to improved sensor properties. Consequently the sensor based on Co 3 O 4 /AgO delivers a remarkable response to triethylamine (TEA) at room temperature (RT) and the best response at 90 °C, which is much lower compared to that (195 °C) of pristine Co 3 O 4 . In addition, the sensor shows fast response time (44 s) and low limit of detection (65 ppb), good selectivity and repeatability for TEA detection. This work provides an effective strategy for developing low temperature gas sensors based on p-type metal oxides. • Heterogeneous Co 3 O 4 /AgO nanorods are synthesized by one-pot hydrothermal method. • AgO nanoparticles can trigger both catalytic and electronic sensitization. • The Co 3 O 4 /AgO sensor delivers a remarkable response to triethylamine (TEA) at room temperature (RT) • The optimum working temperature of Co 3 O 4 /AgO is reduced from 195 °C of pristine Co 3 O 4 to 90 °C.