Redox‐Active Organic Sodium Anthraquinone‐2‐Sulfonate (AQS) Anchored on Reduced Graphene Oxide for High‐Performance Supercapacitors

Abstract

Redox active organic quinones are potentially low cost, sustainable, and high energy pseudocapacitive materials due to their fast and reversible redox reactivity. However, their electrically-insulating nature prevents any practical application. Herein, for the first time, sodium anthraquinone-2-sulfonate (AQS) was examined as an organic redox-active compound and highly conductive graphene nanosheets were incorporated to enhance the electronic conductivity. The -SO 3 functional group of AQS offers excellent hydrophilicity, which promotes the molecular level binding of AQS with reduced graphene oxide (rGO) and leads to a 3D interconnected xerogel (AQS@rGO). The composite exhibits a high specific capacitance of 567.1 F g -1 at 1 A g -1 with a stable capacity retention of 89.1% over 10,000 cycles at 10 A g -1 . More importantly, the optimized composite maintains a high capacitance of 315.1 F g -1 even at 30 A g -1 due to the high pseudocapacitance of AQS and the capacitive contribution of rGO. First-principles calculations further elucidate that AQS offers strong adhesion to rGO sheets with the formation of a space-charge layer, which is favorable for the pseudocapacitance of AQS. This work opens a new avenue for developing high performance supercapacitors though rational combination of redox organic molecules with highly conductive graphene.

Molecular Design Strategies for Electrochemical Behavior of Aromatic Carbonyl Compounds in Organic and Aqueous Electrolytes

“…The sulfur atom and OH in the Reproduced with permission [145] Copyright 2013, Wiley-VCH. [58,147] The characteristics of polybenzoquinone with a sulfur atom or a hydroxyl group in the molecular structure are subsequently summarized. The main driving force for the formation of the VG 8/G hybrid architecture is the π-π interactions between Vat Green 8 and the graphene sheets.…”

Bio‐Inspired Isoalloxazine Redox Moieties for Rechargeable Aqueous Zinc‐Ion Batteries

“…Furthermore, organic electrode materials will add further economic and environmental benefits to the battery systems. [21][22][23] Inspired by the biological energy metabolism in living organisms, organic molecules that mimic redox centers residing in biological system have been investigated as active electrode materials in recent years. [24] These bio-inspired redox-active moieties are capable of undergoing reversible redox reactions during the charge/discharge process.…”

Diaminopyrene modified reduced graphene oxide as a novel electrode material for excellent performance supercapacitors

“…It can be clearly observed that the typical characteristic peaks are located at around 1337 cm À1 and 1591.78 cm À1 , corresponding to the D-band (a representation of the structural defects and unordered carbon of the graphitic structure) and G-band (originated from the E 2g phonon in-plane vibration of sp 2 -bonded carbon atoms), respectively. [29][30][31][32] The intensity ratio of I D /I G was usually used to evaluate the degree of defects and graphitization of carbonaceous materials. The calculated I D /I G values of all prepared samples were 0.86 (GO), 1.25 (rGO), 1.15 (DAPrGO0.5), 1.11 (DAPrGO1), and 1.02 (DAPrGO2).…”

“…The absorption peaks located at around 837.44 cm À1 , 1188.42 cm À1 , 1574.59 cm À1 , and 1718.26 cm À1 could be attributed to the N-H wagging vibration, C-N stretching vibration, N-H bending vibration (it mainly comes from amide bond and the diaminopyrene which are not bonded with graphene functional group), and C-O stretching vibrations which is due to the p-p conjugation of the non-shared electron pair on the N atom in the amide I band with the carbonyl group, respectively. 30,33,34 What's more, combined with the comparison of the spectra of DAP, rGO, and DAPrGOs ( Fig. S3 †), we infer that the broad peak located at around 3356.01 cm À1 and a weak peak located in 3225.84 cm À1 were mainly attributed to the -NH stretching vibration (some -NH bonds of them should come from the formed amide bond) and -NH 2 stretching vibration, as well as a small amount of the stretching vibration of -OH functional groups which not reduced in rGO.…”