Enhancing VOC detection through surface tailoring of CNT film with graphitic carbon nitride

Carbon nanotubes (CNTs) are considered a promising candidate for the detection of volatile organic compounds because of their high specific surface area and excellent electrical and mechanical properties. However, the detecting performance of CNT-based detectors needs to be improved because covalently bonded CNTs are usually chemically inert. We modified the surface of CNT film by coating a graphitic carbon nitride g-C₃N₄ by means of dip coating into ethanol solution of g-C₃N₄. A novel amplification effect has been discovered in the chemo- resistive responses of carbon nanotube (CNT)-based gas sensors. Both CNTs and g-C₃N₄ possess tunable electronic properties. When combined, their electronic structure can be engineered to be highly sensitive to specific gas molecules. The g-C₃N₄ coating can alter the electronic states of CNTs, affecting their conductivity when exposed to vapors of different volatile organic compounds. (author)