Synergistic effect in chemically synthesized noble metal nanoparticles and 2D MoSe2 nanocomposite for enhanced electrochemical performance

Abstract

The two-dimensional (2D) MX2 nanostructured materials, in particular, the MoX2 (X = S, Se) based materials are creating a lot of research interests for their applications in the energy harvesting and storage devices, including in the development of high-performance supercapacitors. However, in this work a facile hydrothermal method is employed to synthesize MoSe2 nanosheets and its composites with the noble metal nanoparticles of platinum (Pt), silver (Ag), and gold (Au) and studied the comparative performances of MoSe2-Pt, MoSe2-Ag and MoSe2-Au nanocomposites electrode materials in development of supercapacitor, which has so far not been reported. The synergistic effect of the large surface area of MoSe2 nanosheets and good electrical conductivity of noble metals has caused drastic modification in the electrode reaction kinetics by fully exposing the active sites of MoSe2-noble metal composites. Thus, the synthesized MoSe2-Au nanocomposite has been found to exhibit the highest specific capacitance (Csp) of 1338 Fg−1 at a current density of 1 Ag−1, which is 1.5 times larger in compared to that of bare MoSe2 nanosheets. Also, an excellent cyclic stability with 95 % capacitance retention even after 500 cycles is reported. A symmetric solid-state supercapacitor is designed by using MoSe2-Au nanocomposite as electrode material, and illumination of a Light Emitting Diode is demonstrated. Thus, the present report will create a lot of interests among the researchers for the development of MoSe2-noble metal based 2D nanocomposite materials for practical energy storage applications.