A reduced graphene oxide/Co3O4 composite for supercapacitor electrode

Abstract

20 nm sized Co 3 O 4 nanoparticles are in-situ grown on the chemically reduced graphene oxide (rGO) sheets to form a rGO-Co 3 O 4 composite during hydrothermal processing. The rGO-Co 3 O 4 composite is employed as the pseudocapacitor electrode in the 2 M KOH aqueous electrolyte solution. The rGOCo 3 O 4 composite electrode exhibits a specific capacitance of 472 F/g at a scan rate of 2 mV/s in a twoelectrode cell. 82.6% of capacitance is retained when the scan rate increases to 100 mV/s. The rGOCo 3 O 4 composite electrode shows high rate capability and excellent long-term stability. It also exhibits high energy density at relatively high power density. The energy density reaches 39.0 Wh/kg at a power density of 8.3 kW/kg. The super performance of the composite electrode is attributed to the synergistic effects of small size and good redox activity of the Co 3 O 4 particles combined with high electronic conductivity of the rGO sheets.

Ni(OH)2/RGO nanosheets constituted 3D structure for high-performance supercapacitors

“…However, the capacitance of the as-prepared Ni(OH) 2 /RGO can also up to 1143 F g -1 at a current density of 1 A g -1 and 730 F g -1 at a current density as high as 20 A g -1 . The capacitive performance of the Ni(OH) 2 /RGO composite is much higher than various electroactive materials, such as RGO/Ni(OH) 2 nanocomposite [27], RGO/NiO nanosheets [28], RGO/NiCo 2 O 4 composite [29,30], RGO/Co 3 O 4 composite [31,32]. All these features demonstrate that the as-prepared Ni(OH) 2 /RGO composite is an excellent electrode material for supercapacitors.…”

Insight into the biosensing of graphene oxide: Present and future prospects

“…Cobalt oxide (CoO x ) nanoparticles-GO heterostructures amplify the signals for glucose detection and 22 provide a green and reproducible method for the development of biosensors for enzyme free detection of glucose. They adhere to the surface of GO making electron transfer process convenient and improve the detection sensitivity Ding et al, 2010;Xiang et al, 2013). CuO NPs based GO biosensors have been reported to be prepared by hydrothermal method for non-enzymatic biosensing of glucose.…”

Self‐Assembled 3D Graphene‐Based Aerogel with Co3O4 Nanoparticles as High‐Performance Asymmetric Supercapacitor Electrode

“…Aspecific capacitance of 472 Fg À1 with acapacitance retention of 95.6 %a fter 1000 cycles is achieved. [23] Althoughs ome nanocomposites combining Co 3 O 4 with various carbon materials have been prepared, the Co 3 O 4 particles in composites are usually considerably agglomerated, which decreases the electrochemically active surfacea rea for reversible faradaic redox reactions between electrolyte and electrode. Moreover,t he specific capacitance, the capacitance retention, and the cycles tability of thesec omposites need to be further improved.…”