Mixed-dimensional heterostructure of few-layer MXene based vertical aligned MoS2 nanosheets for enhanced supercapacitor performance

Abstract

Herein, a mixed-dimensional heterostructure of MoS2 deposited few-layer Ti3C2Tx nanosheets was synthesized to enhance the supercapacitor performance of pristine 2H phase MoS2 and Ti3C2Tx MXene. Through a facile hydrothermal method, with the introduction of MXene, MoS2 vertically aligns on the surface of few-layer Ti3C2Tx nanosheets and forms an interconnected network structure, which helps to increase the specific surface area of electrode material and improve the accessibility of electrolyte. Meanwhile, metallic Ti3C2Tx nanosheets serve as a highly conductive and stable matrix for MoS2 to grow on, incredibly accelerate the electron transfer and alleviate the aggregation of 2H–MoS2, thus bringing with an electrochemical performance improvement. The MoS2–Ti3C2Tx heterostructure shows a great enhancement in supercapacitor performance, which delivers a remarkable specific capacitance of 303.8 F g−1 at the current density of 1 A g−1, about 5 times of 2H phase MoS2 (62.8 F g−1) and 3 times of Ti3C2Tx (105.8 F g−1). Meanwhile, MoS2–Ti3C2Tx heterostructure electrode exhibits excellent cycling stability, which achieves a high capacitance retention up to 82% even after 10,000 cycles. After being assembled to a symmetric supercapacitor, a specific capacitance of 115.2 F g−1 at 0.5 A g−1 was achieved with good Coulombic efficiency (over 90%) and cycling stability (72.3% of capacitance retention after 10,000 cycles). Meanwhile, MoS2–Ti3C2Tx exhibits a high energy density of 5.1 Wh kg−1 at power density of 298 W kg−1, showing excellent SC performance. This study can provide an archetype of constructing mixed-dimensional heterostructure for synergistically integrating the advantages of different materials and enhancing the electrochemical performance.