Coupled interaction of exfoliated hexagonal boron nitride nanosheets decorated with MoS2 nanoflowers to enrich electrochemical activities for hybrid supercapacitor applications

Abstract

Recently, two-dimensional (2D) based electrode materials have been attracted more due to their layered structure, flexibility, increased surface-to-volume ratio, and rapid ion transport properties. Here, the exfoliated h-BN-MoS2 nanocomposites have been developed through the liquid phase exfoliation method assisted to hydrothermal technique. The structure and phases of the synthesized nanocomposites have been studied by XRD analysis. From Raman analysis, the E2g peak is blue-shifted, which confirms the successful formation of exfoliated h-BN nanosheets. The in-depth morphology of the as-prepared exfoliated h-BN-MoS2 nanocomposites have been analyzed by HR-TEM study, in that the exfoliated h-BN nanosheets consisting of 2D-nanoplatelets were successfully decorated with MoS2 nanoflowers. The electrochemical behaviors of the prepared electrodes have been studied in three-electrode systems by CV, EIS, and GCD analysis. As a result, the exfoliated h-BN-MoS2 nanocomposites deliver excellent specific capacity (Cs1) of 411.5 C/g at 10 mV/s scan rate and good capacitive retention of 89.9% after 4000 cycles. From Trasatti analysis, the as-obtained nanocomposites exhibit 571.4 C/g of total (QTo*), 180.9 C/g of outer (Qou*), and 390.4 C/g of inner (Qin*) specific capacity values respectively. In addition, the exfoliated h-BN-MoS2//AC hybrid supercapacitor device (HSC) have been developed, which delivers 196.6 C/g of good specific capacity at 1 A/g current density, and excellent energy density (ED) of 46.1 Wh/kg at the corresponding power density (PD) of 844.9 W/kg. Also, the fabricated device demonstrates 86% of better capacitive retention and 107.2% coulombic efficiency after 2000 charge and discharge cycles. Thus, the ion intercalation and deintercalation through the loosely stacked exfoliated h-BN nanosheets covered with MoS2 nanoflowers manifest excellent charge storage mechanisms in the developed nanocomposite electrode material, thus utilizing them as a promising material for high-power technologies.