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/SnO2 composites with excellent performance synthesized by a chemical precipitation method based on CNF-assisted synthesis, and a series of Au/SnO2 composites were prepared by adjusting the Au content. The sensitivity of the 1.5 wt.% Au/SnO2 sensor to a low concentration of 1 ppm NO2 was 53, nearly 17 times higher than that of pure SnO2 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/SnO2 sensors had good selectivity, repeatability, and stability. Additionally, the sensor is able to maintain its excellent gas sensing performance even under varying humidity conditions.

Automated summary

Au/SnO2 composites with excellent performance were synthesized using a chemical precipitation method based on CNF-assisted synthesis. The 1.5 wt.% Au/SnO2 sensor exhibited a sensitivity of 53 to a low concentration of 1 ppm NO2 under UV irradiation at a wavelength of 365 nm, nearly 17 times higher than pure SnO2 synthesized by CNF. The crystal structure of the composites showed high crystallinity and nanoscale particles. Experimental data demonstrated that the CNF-assisted synthesis Au/SnO2 sensors had good selectivity, repeatability, and stability, even under varying humidity conditions.