Highly selective xylene gas detection based on NiCo2O4 multilayer hexagonal structures

Xylene is a flammable, toxic and harmful inert gas. Achieving highly selective detection of xylene gas is essential for protecting the environment and health, but is full of challenges. Herein, NiCo2O4 with multilayer hexagonal structure has been synthesized through a combination strategy of hydrothermal and annealing, and is applied to detect xylene gas. The effect of composition, surface area, crystallinity and porous degree on gas sensing performance has also been investigated. NiCo2O4 multilayer hexagonal structures annealed at 400 degrees C (NCO MHs400) exhibit a better gas sensing selectivity toward xylene gas compared to NiCo2O4 multilayer hexagonal structures annealed at 500 degrees C and at 600 degrees C (NCO MHs-500 and NCO MHs-600), which predominantly originates from the catalytic oxidation of cobalt component to xylene in the as-prepared pure phase NiCo2O4. Furthermore, NCO MHs-400 presents a superior stability and reliability, well moisture resistance, and a detection limit of 1 ppm toward xylene at a working temperature of 170 degrees C.

Automated summary

In this study, NiCo2O4 with multilayer hexagonal structure was successfully synthesized using a combination of hydrothermal and annealing methods, and applied for the detection of xylene gas. The NiCo2O4 multilayer hexagonal structures annealed at 400 degrees Celsius showed better selectivity and stability.