NO sensing by single crystalline WO3 nanowires

Single crystalline WO3 nanowires were directly grown on FTO substrates by a hydrothermal approach. After calcination at 400 °C, the nanowires assumed an orthorhombic structure and their diameters were mostly in the range of 15–20 nm. The sensor based on the WO3 nanowires exhibited a markedly high response and fast response–recovery characteristics to NO gas at 300 °C. XPS and DRIFT studies demonstrated that the chemisorption of NO and the oxidation of NO by defect-like oxygen anions on the nanowire surfaces were key to the sensing performance.