Enhanced electrochemical performances of organ-like Ti3C2 MXenes/polypyrrole composites as supercapacitors electrode materials

A novel organ-like Ti3C2/PPy nanocomposite has been synthesized via in-situ polymerization of pyrrole monomers to form well-defined and uniformly dispersed polypyrrole nanoparticles on the organ-like Ti3C2 nanosheets under a low temperature. The microstructures and electrochemical properties of Ti3C2/PPy composites with the different mass ration of PPy and Ti3C2 were studied by means of measurement. The analyses reveal that organ-like Ti3C2/PPy nanocomposite exhibits the highest specific capacitance of 184.36 F g(-1) at 2 mV s(-1) and keeps excellent cycling stability almost 83.33% capacitance retention after 4000 charging-discharging cycles at 1 A g(-1). Notably, the high specific capacitance and excellent cycling stability are mainly attributed to the combination of organ-like Ti3C2 nanosheets with electric double-layer capacitor (EDLCs) mechanism and PPy nanoparticles with pseudocapacitance behavior, which take advantages of the synergistic effect between different electrode materials and different energy storage mechanisms to improve the electrochemical performance. The organ-like Ti3C2 as framework limits the growth of PPy, prevents the stacking of PPy, and promotes structural stability of Ti3C2/PPy nanocomposite. Additionally, the intercalation of homogeneous PPy nanoparticles expands the interlayer spacing of Ti3C2, and the highly aligned polymer chains can afford more pathways for electrolyte ions diffusion and charge transfer, therefore increasing the specific capacitance and decreasing the charge transfer resistance. And most of all it has shown a low-cost and convenient way to fabricate large-scale Ti3C2/PPy nanocomposites which has great potential and promising prospect as electrode materials for supercapacitors.