An urchin-like SnO2/NaNbO3 nanocomposite with stable humidity-sensing properties at room temperature

Abstract An urchin-like nano-composite of SnO 2 /NaNbO 3 was fabricated by the hydrothermal method and the influence of the Sn/Nb ratio in the samples on their humidity-sensing properties was investigated. The phases and morphologies of these composites and their elemental distributions were analyzed by X-ray diffraction scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The sensor based on the optimum Sn/Nb ratio of 1:0.4 exhibited remarkable humidity-sensing properties, including a good response ( S  = 4823.8) that was 8.72 times higher than that of the pure SnO 2 sensor ( S  = 553.01). The composites showed rapid response and recovery times (3/9 s), as well as good stability, linearity, and excellent selectivity. The fabrication and humidity-sensing mechanisms were systematically analyzed using analog computations and Nyquist diagrams, respectively. Compared with pure NaNbO 3 and SnO 2 sensors, our easily prepared SnO 2 /NaNbO 3 sensor demonstrates good sensing properties and holds great promise for use in humidity-sensing applications.