Flexible NO2 sensors from renewable cellulose nanocrystals/iron oxide composites

A bio-friendly nanostructured cellulose nanocrystal (CNC) sheet with iron oxide grown on it acting as a nitrogen dioxide (NO2) gas sensor was fabricated by hydrothermal method. The structural investigation was done to monitor the growing mechanism of iron oxide on CNC surface using electron microscope as well as physical and chemical characterization methods. The sensing performance test for NO2 molecules demonstrates that the devices are highly sensitive and fully recoverable at room temperature, which is attributed to the excellent access of nitrogen dioxide molecules to the sensor surface via CNC. The effects of the temperature, durability, and flexibility of sensor are investigated. The reported sensor performance is a huge improvement towards low power consumption and its room temperature operation augurs well for use in various applications.