Enhanced Sensing Performance of Au-decorated Cellulose Nanofiber-SnO2 for NO2 Detection Under UV Light

Cellulose nanofiber (CNF), a natural polymer material with a high specific surface area, is a potential candidate for gas sensors. Here, we report Au/SnO 2 composites with excellent performance synthesized by a chemical precipitation method based on CNF-assisted synthesis, and a series of Au/SnO 2 composites were prepared by adjusting the Au content. The sensitivity of the 1.5 wt.% Au/SnO 2 sensor to a low concentration of 1 ppm NO 2 was 53, nearly 17 times higher than that of pure SnO 2 synthesized by CNF, under ultraviolet (UV) irradiation at a wavelength of 365 nm. The crystal structure of the composite was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), revealing that the composites had high crystallinity and particles reaching the nanoscale. Further experimental data showed that the CNF-assisted synthesis Au/SnO 2 sensors had good selectivity, repeatability, and stability. Additionally, the sensor is able to maintain its excellent gas sensing performance even under varying humidity conditions.