Facile synthesis of ultra-small ruthenium oxide nanoparticles anchored on reduced graphene oxide nanosheets for high-performance supercapacitors

Abstract

Herein, we report a facile, low cost, and environmentally friendly approach to prepare reduced graphene oxide-ruthenium oxide hybrid (RGO-RuO2) materials for supercapacitor electrode applications by in situ sol-gel deposition of RuO2 nanoparticles on the surface of graphene oxide (GO), followed by a reduction of GO in a strong alkaline medium at a low temperature. The combination of the sol-gel route and the reduction of graphene oxide at low temperature resulted in ultrafine, hydrated amorphous RuO2 particles with the size of only 1.0 -2.0 nm, which uniformly decorated the surfaces of RGO sheets. The obtained RGO-RuO2 supercapacitor exhibited excellent electrochemical capacitive performance in a 1M H2SO4 electrolyte with a specific capacitance more than 500 F/g at a current density of 1.0 A/g and high rate performance with the capacitance retention of 86 % when increasing 20 times the current density, from 1.0 to 20.0 A/g in a twoelectrode test cell configuration. The RGO-RuO2 system also showed good cycling stability with a capacitance retention of 87 % after 2000 cycles. The excellent capacitive properties of RGO-RuO2 could be attributed to the uniform anchoring of ultra-small, hydrated amorphous RuO2 nanoparticles on the surface of RGO sheets, resulting in synergistic effects between them. The developed approach represents an exciting direction for enhancing the device performance of the graphenemetal oxides composites supercapacitors and can be used for designing the next generation of energy storage devices.Please do not adjust margins Please do not adjust margins attempts have been made to combine these two kinds of materials.7-17 However, the capacitive performance of RGO-RuO 2 nanocomposites has varied, ultimately depending on the dispersion morphology and crystallinity of RuO 2 particles on RGO. To obtain high capacitive performance, RuO 2 must be in the form of small sized, hydrated, amorphous nanoparticles, uniformly anchored on the surface of an RGO single sheet. 6

Recent Progress in Ruthenium Oxide‐Based Composites for Supercapacitor Applications

“…Herein, hydrated amorphous RuO 2 particles with 1.0–2.0 nm dimensions were homogeneously decorated on the surfaces of rGO sheets. The gravimetric capacitance of 500 F g −1 was acquired in 1 M H 2 SO 4 electrolyte at 1.0 A g −1 current density with capacitance retention ∼87 % after 2000 cycles …”

Enhanced performance of HRGO-RuO2 solid state flexible supercapacitors fabricated by electrophoretic deposition

“…Graphene oxide (GO) was prepared by the modified Hummers method, using expanded graphite as the starting material [15]. The as-prepared GO was diluted to a concentration to 2.0 mg mL -1 and sonicated for 30 min.…”

“…The subsequently fabricated supercapacitor exhibited excellent electrochemical capacitive properties [15]. In another recent study, Xu et al [13] reported a scalable, defect-etching strategy to improve the surface area and mass diffusion rate of RGO by creating nanopores across the entire basal plane of the RGO sheets.…”

Intertwined Titanium Carbide MXene within a 3 D Tangled Polypyrrole Nanowires Matrix for Enhanced Supercapacitor Performances

“…In addition, the irregular size ands egregation of multilayered MXeneb locks make them lose or disconnect the electrical contactb etween them during charge/discharge. [3,[7][8][9][13][14][15][16][17][18][19] The combination of MXene with alien materials such as 0D transition metal oxidesT MOs, [22,32,33] 1D carbon nanotubes (CNTs), [15] 2D reduced graphene oxide (rGO) nanosheets, [20,21,34,36] or the polymers polyaniline (PANI), polyvinyl alcohol (PVA), poly(diallyldimethylammonium) chloride (PDDA), and PPy [16,35,37] to form composites hasb een applied to preventt he restacking. Recent advances have demonstrated that the electrochemical performancesd epends trongly on the nanostructure of the electrode materials.…”