A facile strategy of polypyrrole nanospheres grown on Ti3C2-MXene nanosheets as advanced supercapacitor electrodes

We demonstrated a facile strategy to fabricate the polypyrrole nanospheres/Ti3C2-MXene (PPy/Ti3C2) heterostructure nanocomposite as an advanced supercapacitors electrode material. The well-defined PPy nanospheres with average diameter of about 75 nm were anchored on ultrathin Ti3C2 nanosheets via in situ polymerizations of pyrrole monomers in the introduction of Ti3C2 suspension. The electrode materials of ultrathin Ti3C2 nanosheets and uniform PPy nanospheres with different energy storage mechanisms were effective combined, which made the specific capacitance and cycling stability of the PPy/Ti3C2 heterostructure nanocomposite improved via the synergistic effect between the different EDLCs and pseudocapacitance materials. Furthermore, the electrochemical test with a three-electrode system in 1.0 M H2SO4 solution exhibited that the specific capacitance of the PPy/Ti3C2 heterostructure nanocomposite was as high as 458 F g−1 at the scan rate of 2 mV s−1, which was significantly higher than that of pristine Ti3C2 (132 F g−1). Moreover, the optimal PPy/Ti3C2 nanocomposite showed good cycling stability. In particular, the PPy/Ti3C2-S2 symmetric supercapacitor achieved high energy density of 21.61 Wh kg−1 at the power density of 499.94 W kg−1. Meanwhile, after 4000 charge and discharge tests the initial capacitance retention was 73.68% at 1A g−1. Overall, the novel PPy/Ti3C2 electrode with the stable microstructure and excellent energy storage features has potential to be applied in practical, demonstrating the promising potential of the energy storage device.