Nanoarchitectonics with thiolate protected ultrasmall platinum nanoclusters embedded on ionic liquid matrix for enhanced supercapacitance

Abstract

Herein, we report the synthesis of ultrasmall platinum nanoclusters (Pt-NCs) protected with three different thiols via the chemical reduction method. The varying functionality of these thiols (3-mercapto propane sulfonate (MPS), 3-mercapto propionic acid (MPA) and glutathione (GSH)) in as prepared Pt-MPS, Pt-MPA & Pt-GSH NCs were confirmed using UV-Vis, FTIR, XRD and DLS. The HR-TEM results proved the nanocluster size range for all the three Pt-NCs. The supercapacitance behavior of the three Pt-NCs were boosted by embedding them with a room temperature ionic liquid i.e, an imidazolinium salt (1-decyl-3-methyl imidazolinium salt) as a stable matrix. The ultrasmall nanocluster composition of Pt-MPS NCs, resulted higher redox peak currents at 0.404 V in the scan rate of 50 mV/s than the other two Pt-NCs (Pt-MPA NCs at 0.39 V and Pt-GSH NCs at 0.39 V vs Ag/AgCl respectively). The specific capacitance (Cs) of Pt-MPS, Pt-MPA and Pt-GSH NCs were found to be 805.56, 772.72 and 621.16 Fg^-1 at the current density of 1 Ag^-1. These ultrasmall Pt NCs (Pt-MPS, Pt-MPA and Pt-GSH) embedded with ionic liquid matrix established higher stability, boasting the supercapacitance of Pt NCs which is superior to reported Pt based materials.