Engineering Hierarchical Self-Assembled PANI-/1T@2H MoS2 Nanostructure toward Ultrahigh Performance Supercapacitor Electrodes

Layered transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS2) with mixed phases (1T and 2H) have attracted huge attention as a promising supercapacitor electrode material attributing to their unique physical and electrical properties, abundant catalytically active sites with metallic edges, and high surface area. However, to enhance the electrochemical performance of 1T@2H MoS2 and to overcome the limitations of the stacking between the MoS2 layers, phase engineering and functionalization of MoS2 with polyaniline (PANI) simultaneously are a promising yet challenging way. Herein, we report the tubular uniform growth of PANI on 1T@2H MoS2 templates, where ascorbic acid plays a pivotal role in self-assembling the PANI molecules among themselves. The optimized PANI-/1T@2H MoS2 hybrid functionalized with l-ascorbic acid (L-AA), denoted as PM2, delivers a high specific capacitance of 618 F/g at a current density of 1 A/g and a good rate retention up to 73% with the increase in current density from 1 to 10 A/g in a three-electrode system. Interestingly, the symmetric supercapacitor (SSC) integrated using the PM2 hybrid delivers efficient capacitive property (160 F/g at 0.3 A/g), energy, and power density (8 Wh/kg and 6.1 kW/kg). It has been evidenced that the PM2 hybrid exhibits excellent electrochemical properties as a supercapacitor electrode material, having capacitive retention up to 98.1% even after completing 8000 cycles at a current density of 2 A/g. Additionally, PM2 SSCs possess an excellent degree of mechanical properties and flexibility, and they are able to power a red LED successfully when connected in series. Furthermore, the experimentally observed results are compared and justified with the theoretical findings. Our strategy of growing PANI onto L-AA functionalized 1T@2H MoS2 provides a possible pathway to enhance the electrochemical performance of PANI/MoS2-based hybrid materials for the design of future-generation energy storage devices.