In situ polymerized polyaniline/MXene (V2C) as building blocks of supercapacitor and ammonia sensor self-powered by electromagnetic-triboelectric hybrid generator

This paper reports in situ polymerization of polyaniline (PANI)/MXene (V2C) composites as building blocks of supercapacitor and ammonia sensor self-powered by electromagnetic-triboelectric hybrid generator. The high accessible surface of MXene produced abundant high reactivity and electronegativity sites, which could promote or induce the polymerization of aniline on its surface and the polymerization of aniline on its surface could prevent its re-stacking and enhance its electrochemical activity, which could significantly improve the performance of ammonia sensor and supercapacitor. The working principle of the integrated self-power system is to use the hybrid nanogenerator of triboelectric nanogenerators (TENGs) and electromagnetic generator (EMGs) to charge the supercapacitor for driving the ammonia sensor. The supercapacitor utilized PANI/MXene as anode and active carbon as cathode, which displays a capacitance of 337.5 F/g at the current density of 1 A/g, a considerable energy density of 11.25 Wh/kg and a power density of 415.38 W/kg. The sensing material of PANI/MXene nanosheets have an eye catching response value ((Rg-Ra)/Ra = 14.9% @ 1 ppm NH3), good stability (more than 60 days) and fast response/recovery time (9 s/9 s @ 1 ppm NH3), which is much better than the pristine PANI and MXene nanosheets. This work provided a candidate of PANI/MXene for constructing supercapacitor and sensing elements, which opened up an avenue for the integration of self-power gas sensing for industrial and agricultural pollution.