Gas-Sensitive Cellulosic Triboelectric Materials for Self-Powered Ammonia Sensing.

Gas-sensitive materials are capable of dynamic identification and content monitoring of specific gases in the environment, and their applications in the field of gas sensing are promising. However, weak adsorption properties are the main challenge limiting the application of gas-sensitive materials. A highly adsorbent gas-sensitive cellulose nanofibril (CNF)-based triboelectric material with a layered structure is prepared here and it is applied to self-powered gas sensing. The layered structure of the triethoxy-1H,1H,2H,2H-tridecafluoro-n-octylsilane cellulose nanofiber (PFOTES-CNF)-based gas-sensitive material further enhances the adsorption of the material due to electrostatic adsorption in the electrostatic field induced by triboelectricity. It is found that the ammonia-sensitive material obtained by loading Ti₃ C₂ T_x in PFOTES-CNF has a fast response/recovery (12/14 s), high sensitivity response (V_air /V_gas  = 2.1), high selectivity response (37.6%), and low detection limit (10 ppm) for 100 ppm of ammonia gas. In addition, the ammonia-sensitive CNF-based triboelectric material can accurately identify NH₃ concentration changes in the range of 10-120 ppm and transmit the signal wirelessly to the user interface, facilitating real-time online monitoring of NH₃ in the environment. A novel strategy is provided here for designing and preparing high-performance gas-sensitive composites and the analysis of self-powered gas sensing is guided.