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

Abstract

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 NO_x 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 La_0.8Sr_0.2CoO₃ (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.