Facile synthesis of ruhtenium nanoparticles capped by graphene and thiols for high-performance supercapacitors

Abstract 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 × 105 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.