Nitrogen and Sulfur Co‐Doped Graphene‐Like Carbon from Industrial Dye Wastewater for Use as a High‐Performance Supercapacitor Electrode

Abstract

Nitrogen and sulfur co‐doped graphene‐like carbon (N,S‐GLC) is successfully prepared in a one‐step hydrothermal reaction of glucose with industrial dye wastewater followed by chemical activation. The nitrogen and sulfur are sourced entirely from the industrial wastewater. The process not only provides an alternative way of treating industry wastewater, but also offers a green route for recovering energy from the waste in the form of chemicals. The resultant N,S‐GLC shows a good degree of graphitization, a high specific surface area (1734 m2 g−1), and moderate heteroatom doping (N: 2.1 at%, S: 0.7 at%). The N,S‐GLC electrode displays high specific capacitance of 275 F g−1 at a current density of 0.5 A g−1 with a retention of 65.4% at 20 A g−1 in 6 m KOH. Moreover, the assembled symmetrical supercapacitor cell shows a capacitance of 38 F g−1 at a current density of 0.5 A g−1, which is equivalent to an energy density of 6.4 Wh kg−1 at a power density of 275.0 W kg−1. This approach provides an alternative and sustainable way of fabricating heteroatom‐doped graphene‐like carbon materials for use in high‐performance supercapacitors.

Hydrothermally Synthesized Sulfur-Doped Graphite as Supercapacitor Electrode Materials

“…All of these S-doped PCMs imparted PC-type behavior. This generally happens because the presence of a much larger heteroatom boosts the Faradaic current to a large extent. , Apart from the laboratory chemicals, − biomass , and industrial and agricultural waste are also used for the synthesis of S-doped PCMs for sustainable development. However, in most cases, prolonged processing was required with harsh conditions.…”

“…However, in most cases, prolonged processing was required with harsh conditions. In addition, it led to uncontrolled dopant entry because N doping also took place along with S doping. , Therefore, selective S doping in PCMs is highly desirable using greener and cheaper chemicals, following relatively mild conditions.…”

Design of Ultra‐Microporous Carbons by Interpenetrating MF Prepolymer into PAAS Networks at Molecule Level for Enhanced Electrochemical Performance

“…The results show that the electrode has favorable kinetics and high power capacitance performance in the KOH electrolyte. The energy density and power density of the device is summarized in the Ragone plot of Figure f, which shows a high energy density of 17.13 Wh kg −1 at the power density of 900 W kg −1 , and much higher than other previously reported materials such as ANCLCNFs, NFMCNFs, C‐blank, Z‐HPAC, CLCNF/PANi, HGPC‐A, N,S‐GLC, NPCs and other carbon materials related symmetrical devices . In contrast, the energy density of the device in KOH solution is only 7.15 Wh kg‐1, which is less than half that in Na 2 SO 4 solution, and smaller in H 2 SO 4.…”

“… The devices: (a) CV curves in 6 M KOH, (b) CV curves in 1 M Na 2 SO 4 , (c) CV curves in 1 M H 2 SO 4 , (d) electrochemical impedance spectroscopy, (e) bode plots (inset is the time constants, τ) in different electrolytes, and (f) Ragone plot in different electrolytes and the comparison with other reported works ANCLCNFs, NFMCNFs, C‐blank, Z‐HPAC, CLCNF/PANi, HGPC‐A N,S‐GLC, NPCs …”

“…As a device, it demonstrates optimized power density and energy density of 18 kW kg À 1 and 17.13 Wh kg À 1 in 1 mol L À 1 Na 2 SO 4 , respectively. ANCLCNFs, [35] NFMCNFs, [36] C-blank, [37] Z-HPAC, [38] CLCNF/PANi, [39] HGPC-A [40] N,S-GLC, [41] NPCs. [42]…”