▎ 摘　　要

Clean and sustainable energy storage is of increasing demands due to uncontrolled fossil fuel depletion and rapid global economy growth. At the same time, low cost and environmental-friendly electrode materials are desirable to speed up industrial smart device fabrication. We constructed high-energy supercapacitor with the electrode of ruthenium and manganese oxide nanoparticles (RM NPs) loaded reduced graphene oxide (RGO). Simultaneous preparation of high capacitive metal oxide nanoparticles on graphene allows low chemical consumption, while favorable reaction temperature, short reaction time and simple methodology open a way for the production. Physico-chemical characterization was carried out to analyze the nanostructure and chemical composition of the nanocomposites. Experimental results highlighted: 2-10 nm oxide nanoparticles were uniformly decorated on 2D-nanosheets of RGO. RM NPs enlarged RGO inter layers, giving enriched micro- and meso-pores. While assembling the nanocomposites as symmetric supercapacitor electrodes in 0.5 M KOH, they delivered a high capacitance of 641 Fg(-1) and energy density of 22.26 Wh kg(-1) and retain initial capacitance over 1000 cycles. The excellent performance and robust stability demonstrate that the metal oxide loaded graphene composites allow us to develop highly efficient and low cost metal-based supercapacitors. (C) 2018 Published by Elsevier Ltd.