Facile Synthesis of Ruhtenium Nanoparticles Capped by Graphene and Thiols for High-Performance Supercapacitors

Ru nanoparticles (Ru@G, Ru@HT, Ru@DT, and Ru@OT) were prepared by facile chemical reduction of RuCl3 and graphene or thiols. The morphologies and structures of these Ru nanoparticles were ascertained by TEM, FTIR, UV-vis, and XPS, confirming the metallic Ru cores were capped by graphene or thiols. Their applications for supercapacitors were investigated in 0.5 M H2SO4 electrolyte, using cyclic voltammetry, galvanostatic charging-discharging test, and electrochemical impedancemetry. Compared as Ru@HT, Ru@DT, and Ru@OT nanoparticles, Ru@G exhibited greatly improved electrochemical performance and stability. It showed a specific capacitance of 1013 F g(-1) at 0.004 V s(-1) , an energy density of 34.8 W kg(-1) at the power density of 1.79 x 10(-5) W kg(-1), the capacitance retention of 94.9% after 10,000 cycles. The peripheral graphene has good stability and excellent electrical conductivity, so it can provide Ru core stable protection as well as good electron transfer routes, thus Ru@G are suitable for implementation in electrochemical applications. (C) 2021 Elsevier Ltd. All rights reserved.