Perovskite-sensitized β-Ga2O3 nanorod arrays for highly selective and sensitive NO2 detection at high temperature

Amongst various gaseous pollutants, NO2 is one of the major exhausts originating from fossil fuel and gas combustions in vehicle engines and power plants at high temperature. Under such a scenario, in situ and real-time gas detection and monitoring solutions are largely limited, which hinders the energy-efficient and resource-saving operations of these advanced energy systems. In this report, a new type of perovskite-sensitized β-Ga2O3 nanorod-array has been successfully fabricated to detect NOx at high temperature selectively and sensitively. The demonstrated gas sensors are highly sensitive to NO2 at 800 °C, with excellent reversible and reproducible response characteristics. Through the surface decoration of perovskite-type La0.8Sr0.2CoO3 (LSCO) nanoparticles, the sensitivity of β-Ga2O3 nanorod array gas sensors is enhanced by nearly an order of magnitude, along with much faster response dynamics. A remarkable selectivity toward oxidative gases was also demonstrated with the robust differentiation of NO2.