High precision NH3 sensing using network nano-sheet Co3O4 arrays based sensor at room temperature

Network nano-sheet arrays of Co3O4 for high precision NH3 sensing application were prepared on alumina tube using a facile hydrothermal process without template or surfactant, and their morphology, nanostructures and NH3 gas sensing performance were investigated. The prepared nano-sheet Co3O4 arrays showed a network structure with an average sheet thickness of 39.5 nm. Detailed structural analysis confirmed that the synthesized Co3O4 nano-sheets were consisted of nanoparticles with an average diameter of 20.0 nm. NH3 gas sensor based on these network Co3O4 nano-sheet arrays showed a low detection limit (0.2 ppm), rapid response/recovery time (9 s/134 s for 0.2 ppm NH3), good reproducibility and long-term stability for NH3 detection at room temperature.