Quartz Crystal Nano-balance for hydrogen sensing at room temperature using carbon nanotubes aggregates

The gas sensor based on carbon nanotubes are presently receiving considerable attention because of the outstanding properties, such as faster response, higher sensitivity, lower operating temperature and robustness of the nanotubes in comparison with the other types of sensing materials. In the present research, we demonstrate detection of hydrogen at room temperature using a Quartz Crystal Nano-balance (QCN) and as sensing material, Single-Walled Carbon Nanotubes (SWCNTs ) dispersed in a polythiophene matrix. The experimental determination of H 2 in H 2/N 2 mixtures has been performed by using a counter frequency and observing the frequency shifts induced in a quartz crystal resonator by H 2 adsorption and consequent mass variation of the active layer deposited on the quartz. The high sensitivity of the realized nano-balance allows us to observe mass variations up to few nanograms /Hertz and to detect up to 1% of H 2. The good sensing performances of the nanotube-based material make unnecessary the use of any catalyst species for H 2 detection. Moreover this QCN device is able to work with good efficiency at 23 °C and 1 Atm.