Adsorption Of Electrolyte Ions Research Articles

Reduced graphene oxide-based silver selenide nanocomposite synthesized through hydrothermal method for oxygen evolution reaction

Intensive research is being conducted on electrochemical water splitting to deal with environmental issues and energy concerns. The renewable and environment-friendly energy sectors want to develop inexpensive electrocatalysts with prolonged stability and high electrocatalytic activity and accelerate oxygen evolution reaction (OER). The current study reports the fabrication of Ag2Se nanoparticles on reduced graphene oxide (rGO) to create Ag2Se/rGO nanocomposite through hydrothermal method at 165 ℃. Raman analysis validated the good integration of rGO and Ag2Se, revealing distinctive peaks for both materials. The produced nanocomposite has a Tafel plot (34 mV/dec) and overpotential (η) 192 mV at ideal current density (j) 10 mA/cm2. Chronoamperometric study and cyclic durability of the nanocomposite demonstrate stability over 60 hours. The electrochemical impedance spectra (EIS) showed that the Rct (charge transfer resistance) of Ag2Se/rGO was 0.2 Ω. The electrochemical finding indicates that the incorporation of rGO into Ag2Se provides a large surface area and greater active regions which facilitates the faster adsorption of electrolyte ions and reduced the resistance. The current research reveals a novel methodology to produce highly active rGO-based electrocatalysts that enhance long-term OER performance and open new avenues for their extensive application in the energy sectors.

Novel bowl-like or capped carbon with a low carbon footprint as electrode material in EDLCs

Large surface area, excellent electrical conductivity, homogeneous structure, and extended cycling stability are desirable characteristics for energy materials. Carbon-derived structures exhibit porous structure, work well in a wide potential window, and are highly conductive. Hence, they can show enhanced rate capability and cycle life. Despite ongoing efforts, the synthesis of carbons at lower temperatures remains a challenge. In comparison, the high-temperature synthesis protocols lead to a high CO2 footprint. Here, we report the synthesis of unique carbon morphologies, namely capped carbon nanostructures (CCS) and bowl-like carbon structures (BCS). Their performances are either comparable or higher than those conventionally used morphologies of carbon, such as nanospheres, microspheres, nanotubes, graphene oxide, and layered structures. The four-sided opening in BCS particles ensures higher adsorption of electrolyte ions, which is even higher than hierarchical or spherical structures. The cap formation on the CCS acts like an additional layer on top of the sphere. Further, the CCS is arranged in a sequential honeycomb array, which leads to the formation of definitive channels for electrolyte diffusion. The unique carbon morphologies showed nearly ∼ 40 % increment in the specific capacitance values compared to other commonly used carbon structures. The novel morphologies also have a much lower carbon footprint, as shown by the life cycle assessment (LCA) studies.

Investigating the CoS2 Mass Fraction Enhancing Performance Supercapacitor for Medium Low Consumption

Supercapacitor are one of the most environmentally friendly electrical energy storage devices. Improvement of supercapacitor performance continues to be carried out by combining active materials and transition metal oxides/hydroxides. In this study, a composite electrode material based on activated carbon with a mass percent variation of CoS2 has been successfully carried out. The composition of Ni(OH)2 - CoS2 /Graphene Nanosheet//Carbon electrode consists of 10, 15, and 20% CoS2 . The electrodes were then characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope - Energy Dispersive X-ray (SEM-EDX). The research was continued by fabricating a symmetric coin cell. Supercapacitor device performance was characterized using Cyclic Voltammetry (CV), Charge-Discharge (CD) and Electrochemical Impedance Spectroscopy (EIS). The morphology of activated carbon shows porous chunks that are beneficial in the electrolyte ion adsorption process. While CoS2 and Ni(OH)2 materials indicated in bulk form. Characterization results show the most optimum sample is in the 15% CoS2 sample with EIS characterization showing the smallest equivalent series resistance (ESR) of 0.81 Ω. CD characterization results were able to have specific capacitance, energy density and power density of 58.25 Fg-1, 1.59 Wh/kg, and 70.49 W/kg respectively and were able to survive up to 88.84% after 1000 test.

Blooming flower like BiOBr decorated RGO nanocomposite as advanced electrode material for high performance supercapattery applications

The present work deals with a synthesis and characterization of bismuth oxybromide decorated reduced graphene oxide (BiOBr/RGO) nanocomposite as working electrode for supercapattery applications. where solvothermal method was adopted for the preparation of BiOBr/RGO nanocomposite. The prepared BiOBr depicts blooming flower-like microspheres and the presence of voids between petals could enable more adsorption of electrolyte ions and also act as conductive channels for easy ion diffusion. Further, the addition of GO with BiOBr resulted in an unfurling flower like morphology for BiOBr/RGO nanocomposite. The BiOBr/RGO (BiOBr – 3 wt% of GO) nanocomposite exhibits supreme specific capacity (Cs) of 3254 C/g at 1 A/g, energy density of 207 Wh/kg at 1 A/g and cyclic stability of 1000 cycles with a capacity retention rate of 97%. These outstanding electrochemical performances suggest that the prepared BiOBr/RGO nanocomposite may serve as a promising working electrode for supercapattery applications in the near future.

Wet-chemical engineering of Ag-BiVO4/Bi2S3 heterostructured nanocomposite on graphitic carbon nitride (g-C3N4) sheets for high performance supercapacitor application

Graphitic carbon nitride (g-C3N4), a structural analogue of graphite has opened a new arena in energy storage. The N-rich g-C3N4 sheets similar to N-doped carbon materials provide large number of defect sites for increased diffusion and adsorption of electrolyte ions. High N-content in g-C3N4 is most suitable to escalate metal‑carbon binding energy which stabilizes the pseudo-active transition metal oxides/chalcogenides over carbon support to realize high capacitive performance. In this study, we have impregnated binary Ag-BiVO4/Bi2S3 heterostructures on g-C3N4 sheets through wet-chemical approach, as novel electrode material for supercapacitor application. As prepared Ag-BiVO4/Bi2S3@g-C3N4 composite (ABVBS@g-C3N4) along with Ag-BiVO4/Bi2S3 (ABVBS), Ag-BiVO4 (ABV), and Bi2S3 (BS) were systematically characterized by different techniques i.e., XRD, FTIR, FESEM, EDS, and BET analysis. When applied for electrochemical tests, among all the analyzed electrodes ternary composite ABVBS@g-C3N4 exhibited highest electrochemical activity with a specific capacitance value of 872 F/g (@5 mV/s) and 815.4 F/g (@1 A/g), and 91.5 % capacitance retention up to 5000 GCD cycles. The initial coulombic efficiency of ABVBS@g-C3N4 was noteworthy (99.42 %) due to very low internal resistance. Moreover, it was analyzed that ternary composite ABVBS@g-C3N4 has lower equivalent series resistance (RES) as 6.73 Ω and charge transfer resistance value as 7.73 Ω, in comparison to other electrodes. This excellent electrochemical performance of ABVBS@g-C3N4 is attributed to combined contributions from ABVBS and g-C3N4 in terms of multiple redox states, increased wettability of electrode, and high structural and chemical stability. Considering the results, our study proposes feasible strategy to generate hybrid electrode materials with optimized properties to serve as energy storage material for next generation supercapacitors.

Electrochemical Performance of Corn Waste Derived Carbon Electrodes Based on the Intrinsic Biomass Properties.

The exploration of cost-effective and sustainable biomass-derived carbon materials as electrodes for energy conversion and storage has gained extensive attention in recent research studies. However, the selection of the biomass and the electrochemical performance regulation of the derived biochar, as well as their interrelationship still remain challenging for practical application. Herein, corn wastes with high carbon content (>40%), corn cob and corn silk, were selected as precursors for the preparation of high value-added and high yield carbon materials via a modified synthetic process. Uniquely, this work put emphasis on the theoretical and experimental investigations of how the biomass properties influence the composition and nanostructure regulation, the electrolyte ion adsorption free energy, and the electrical conductivity of the derived carbon materials as well as their electrochemical performance optimization. Owing to the favorable specific surface area, the hierarchical porous structure, and the diverse elemental distribution, corn cob and corn silk derived carbon materials (CBC and SBC) present great potential as promising electrodes for alkaline aqueous zinc batteries and supercapacitors. The assembled CBC//Zn and SBC//Zn zinc batteries deliver high energy densities of 63.0 Wh kg-1 and 39.1 Wh kg-1 at a power density of 575 W kg-1, with excellent cycling performance of 91.1% and 84.3% capacitance retention after 10,000 cycles. As for the assembled symmetric supercapacitors, high energy densities of 14.9 Wh kg-1 and 13.6 Wh kg-1, and superior long-term cycling stability of 99.3% and 96.6% capacitance retention after 20,000 cycles could be achieved. This study highlights the advantages of utilizing corn cob and corn silk as carbon sources on the designed synthesis of carbon electrodes, and presents a meaningful perspective in the investigation of biomass-derived carbon materials and their potential applications in rechargeable devices.

Waste to wealth: Oxygen-nitrogen-sulfur codoped lignin-derived carbon microspheres from hazardous black liquors for high-performance DSSCs

Carbon materials are effective substitutes for Pt counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). However, many of these materials, such as carbon nanotubes and graphene, are expensive and require complex preparation process. Herein, waste lignin, recycled from hazardous black liquors, is used to create oxygen-nitrogen-sulfur codoped carbon microspheres for use in DSSC CEs through the facile process of low-temperature preoxidation and high-temperature self-activation. The large number of ester bonds formed by preoxidation increase the degree of cross-linking of the lignin chains, leading to the formation of highly disordered carbon with ample defect sites during pyrolysis. The presence of organic O/N/S components in the waste lignin results in high O/N/S doping of the pyrolysed carbon, which increases the electrolyte ion adsorption and accelerates the electron transfer at the CE/electrolyte interface, as confirmed by density functional theory (DFT) calculations. The presence of inorganic impurities enables the construction of a hierarchical micropore-rich carbon structure through the etching effect during self-activation, which can provide abundant catalytically active sites for the reversible adsorption/desorption of electrolyte ions. Under these synergistic effects, the DSSCs that use this novel carbon CE achieve a quite high power-conversion efficiency of 9.22%. To the best of our knowledge, the value is a new record reported so far for biomass-carbon-based DSSCs.

Application of long fibrous coconut silk-based porous carbon in flexible supercapacitor

All-solid-state flexible supercapacitors are considered to be one of the ideal candidates for energy storage in the next generation of wearable electronic devices due to their high capacitance performance and excellent mechanical flexibility. Biomass-based carbon materials are regarded as the ideal precursors for carbon-based electrode materials due to their wide sources, low cost, natural and abundant biological features. In this work, long-fiber coconut silk with vascular bundle structure was selected as the precursor, the controllable adjustment of the pore structure and conductive characteristics of the electrode material was achieved by changing the KOH activation temperature. The specific surface area of the activated carbon electrode material etched with KOH at 900 °C can reach 2794 m2·g−1. The high specific surface area and reasonable pore size distribution provide abundant active sites for the adsorption of electrolyte ions, which leads to the excellent electrode specific capacitance (2 mV·s−1，634 F·g−1，10.73 Wh·kg−1) of the symmetric flexible supercapacitor combined with PVA (polyvinyl alcohol)/H2SO4 gel electrolyte. At the same time, the long-fiber carbon skeleton has intrinsically high Young's modulus, which enables the flexible all-solid-state supercapacitor to maintain better electrochemical stability and mechanical durability under mechanical deformation, and it's retention rate can reach 101.5 % after 10,000 bending experiments at an inner angle of 140°. It proves the great advantages and potential of coconut silk-based biomass carbon materials in the field of preparing flexible supercapacitors, and promotes the development of energy storage units for next-generation wearable electronic devices.

Tailoring the charge storability of commercial activated carbon through surface treatment

Sustainability concerns in the electrochemical charge storage realm revitalized research on the electrochemical capacitors (ECs), or synonymously, supercapacitors (SCs), because of the renewability of their electrode materials and environmental benignity thereby, longer life cycle to improve materials circularity, and their inherent superior rate charging/discharging than batteries. As SCs store energy via the reversible adsorption of electrolyte ions on the electrode pores, maximizing the number of pores to accommodate the ions is the most desired way to improve the charge storability. In this regard, we report herewith a simple and facile approach for engineering the porosity of commercial activated carbon by refluxing it in nitric acid as a function of time; the BET surface area of the 72 h refluxed samples increased by 75 %. Charge storage properties of the modified electrodes are evaluated in a three-electrode system configuration in 1 M Na2SO4 electrolyte; a 75 % increase in the surface area led to an increase in specific capacitance over 110 % following a significant reduction in Warburg impedance. Besides, symmetric SC full cells were fabricated by varying the electrode mass between 3 and 14 mg·cm−2 in five steps. All the fabricated devices achieved a potential window of 1.8 V in 1 M Na2SO4. The highest mass loaded (∼14 mg·cm−2) device fabricated using the prepared material has delivered a maximum capacitance of ∼990 mF, the maximum areal capacitance of ∼494 mF·cm−2, an energy density of ∼13 mWh·cm−3, and a maximum power density of ∼2189 mW·cm−3. The device also maintained ∼97 % retention in capacitance with a remarkable coulombic efficiency of ∼97 % after 5000 cycles. The performance of the device is comparable with the commercial SCs used for low voltage DC hold-up applications such as embedded microprocessor systems. The procedure developed herewith supports easy recycling and reusing of the activation agent, and thereby reduces the release of toxic chemicals into the environment.

Electrochemical reactivity of atomic and molecular species under solid-state confinement

The nanoconfinement of electrochemically-active guest species in host solid state electrode materials provides opportunities to tune mass transport between the bulk electrolyte and inner surface of the electrode, enhance electron-transfer rates, and/or improve the stability and dispersion of active material. This review summarizes recent experimental and theoretical electrochemical studies of three types of nanoconfined guest species: (1) ion adsorption of electrolyte ions, (2) confined redox-active molecules, and (3) electrocatalytic reactions of confined ions/solvents and catalytic particles. The examples discussed in this review illustrate how the confinement of guest species within enclosed spaces with nanoscale dimensions – such as pores, pockets, channels, and interlayers – can lead to improved electrochemical performance.

N/S co-doped interconnected porous carbon nanosheets as high-performance supercapacitor electrode materials

The synthesis of porous carbon nanosheets without acid treatment for high-performance supercapacitors (SCs) is difficult. We report the construction of N/S co-doped porous carbon nanosheets (NS-PCNs) from coal tar pitch (CTP), using Na2S2O3·5H2O as the sulfur source and K2CO3 as an activator, under flowing ammonia at high temperature. NS-IPCN800 prepared at 800 °C is composed of two-dimensional (2D) nanosheets with abundant pores and an interconnected 3D carbon skeleton. The abundant microspores increase the number of active sites for electrolyte ion adsorption and short mesopores act as channels for fast ion transmission. The 3D carbon skeleton provides paths for electron conduction. Heteroatom doping provides an additional pseudocapacitance for the NS-IPCN electrodes. As a result, the NS-IPCN800 electrode has a high capacitance of 302 F g−1 at 0.05 A g−1 in a 6 mol L−1 of KOH electrolyte, and has a high energy density of 9.71 Wh kg−1 at a power density of 25.98 W kg−1. It also has excellent cycling stability with a capacitance retention of over 94.2% after 10 000 charge-discharge cycles. This work suggests an environmentally friendly way to produce NS-IPCNs from CTP for use as high-performance SC electrode materials.

Highly active N, S Co-Doped Ultramicroporous Carbon for High-Performance Supercapacitor Electrodes.

N, S-doped ultramicroporous carbons (NSUC-x) with a high nitrogen/sulfur content and a narrow pore-size distribution of around 0.55 nm were firstly prepared using L-cysteine as a nitrogen and sulfur source. The phase, graphitization degree, morphology, specific surface area, pore structure and surface condition of NSUC-x are investigated to analyze the key role in electrochemical performance. Such an ultramicroporous structure and N, S doping not merely provide a high-specific surface area and a suitable pore size, but also induce a good wettability for the fast transport and adsorption of electrolyte ions. Due to the above strategies, the typical NSUC-0.4 exhibits a high gravimetric capacitance of 339 F g−1 at 0.5 A g−1 as well as a capacity retention of 91.6% after 10,000 cycles in a three-electrode system using a 6 M KOH electrolyte. More attractively, a NSUC-0.4-assembled symmetrical supercapacitor delivers an energy output of 7.4 Wh kg−1 at 100 W kg−1 in 6 M KOH as well as a capacity retention of 92.4% after 10,000 cycles, indicating its practical application prospect. Our findings open up new prospects for the design and electrochemical application of N, S-doped ultramicroporous carbons.

Ionic liquid modified graphene aerogel as efficient electrode material for supercapacitors based on ionic liquid electrolyte

The simultaneous enhancement of energy density (E) and power density (P) is a highly pursued but difficult task in domain of supercapacitors, which necessitates good electrode/electrolyte compatibility, high electron/ion migration rates, and wide voltage window. Herein, an ionic liquid (IL) assisted hydrothermal reduction and modification tactics is employed to prepare 1-benzyl-3-methyl imidazolium cysteine ([Bzmim][Cys]) IL-modified reduced graphene oxide aerogel material (IL-rGA). The porous texture with suitable pore sizes and IL-modified surface of IL-rGA ensures rapid infiltration and sufficient adsorption of electrolyte ions, and therefore substantially enhances the specific capacitance. The symmetric IL-rGA supercapacitor using 1-ethyl-3-methyl tetrafluoroborate IL electrolyte delivers high E values of 104–33 W h kg−1 in the P range of 944–15,860 W kg−1, these output parameters can meet the requirements in more widespread electric facilities. The current work offers a promising way to enhance and balance the E and P values of carbonaceous supercapacitors via the surface modification of electrode materials and the matching with IL electrolytes.

Less-Energy Consumed Hydrogen Evolution Coupled with Electrocatalytic Removal of Ethanolamine Pollutant in Saline Water over Ni@Ni3 S2 /CNT Nano-Heterostructured Electrocatalysts.

Energy crises, environmental pollution, and freshwater deficiency are critical issues on the planet. Electrolytic hydrogen generation from saline water, particularly from salt-contained hazardous wastewater, is significant to both environment and energy concerns but still challenging due to the high energy cost, severe corrosion, and the absence of competent electrocatalysts. Herein, a novel strategy is proposed for energy-efficient hydrogen production coupled with electro-oxidation removal of ethanolamine pollutant in saline water. To achieve this, an active and durable heterostructured electrocatalyst is developed by in situ growing Ni@Ni3 S2 core@shell nanoparticles in cross-linked 3D carbon nanotubes' (CNTs) network, achieving high dispersibility and metallic property, low packing density, and enriched exposed active sites to facilitate fast electron/mass diffusion. The unique Ni@Ni3 S2 /CNTs nano-heterostructures are competent for long-term stably electro-oxidizing environmental-unfriendly ethanolamine at a high current density of 100mA cm-2 in saline water, which not only suppresses oxygen and chloride evolution reactions but also decreases the energy consumption to boost hydrogen production. Associated with experimental results, density functional theory studies indicate that the collaborative adsorption of electrolyte ions and ethanolamine molecules can synergistically modulate the adsorption/desorption properties of catalytic active centers on Ni@Ni3 S2 /CNTs surface, leading to long-term stabilized electrocatalysis for efficient ethanolamine oxidation removal and less-energy hydrogen simultaneous production in saline water.

Ultrahigh‐areal‐capacitance aqueous supercapacitors enabled by soft biomass‐derived porous carbon membrane

Sustainable biomass-derived carbons in powdery forms have shown to be high-performance capacitive electrode materials for application in supercapacitors (SCs) due to their large specific surface area, distinct porous structure, and low cost; however, their practical applications are being largely hampered due to their powdery status-related issues including tedious electrode assembly process and insufficient capacitance and cycling stability. Herein, we develop a porous carbon membrane, termed as PECM, by direct carbonization of Pleurotus eryngii (PE) using KOH as activator. The as-fabricated PECM features a hierarchically nanostructure with high porosity, large specific surface area, and excellent electrolyte wettability, which cannot only afford a large usable active area for the interfacial adsorption of electrolyte ions but also supply fast diffusion pathways for electrolyte ions. Moreover, the as-fabricated PECM is doped with N and also has large amounts of O, S, and P-containing functional groups, which would be expected to contribute additional pseudocapacitance. More importantly, the as-fabricated PECM has excellent mechanical performance and can be directly used to assembly an aqueous symmetric SC device. Attributing to the above structural merits of PECM, the two-electrode symmetric SC assembled using two identical PECM-800 electrodes (~20 mg cm−2 for each electrode), exhibits excellent electrochemical performance with ultrahigh areal capacitance (4.6 F cm−2 at 10 mA cm−2), excellent long-term cycling stability (113% capacitance retention after 20 000 cycles), and superior energy densities of 0.24 to 0.09 mWh cm−2 at power densities of 5.20 to 51.9 mW cm−2. This work offers a new insight on employing biomass to prepare value-added and practically applicable carbon materials for the application in SCs.

Design rules of pseudocapacitive electrode materials: ion adsorption, diffusion, and electron transmission over prototype TiO2

The development of a high-performing pseudo-capacitor requires a comprehensive understanding of electrode materials from the aspects of electron transfer and electrolyte ion adsorption and diffusion. Herein, these factors are considered over the prototype TiO2, and a high pseudo-capacitance is achieved via the introduction of various defects, i.e., oxygen defect (VO) and co-doped defect (VO+NO). The study is based on joint explorations of first-principle calculations and the transfer matrix method. Relative to pristine TiO2 (300 F g−1), defective TiO2 produces pseudocapacitance as high as 1700 F g−1. Moreover, defects induce small barriers for electron transmission caused by surface band bending. The climbing image nudged elastic band diffusion of H ions displays a much higher barrier in TiO2−VO than in TiO2−VO+NO. Such a result indicates easy H diffusion in the co-doped system. This work provides insights into the adsorption and diffusion of electrolyte ions and the influence of defects on electron transfer. The results are also significant for the design and optimization of electrode materials for the next generation of supercapacitors.

Catalytic Role of Adsorption of Electrolyte/Molecules as Functional Ligands on Two-Dimensional TM-N4 Monolayer Catalysts for the Electrocatalytic Nitrogen Reduction Reaction.

Two-dimensional single-atom catalysts (2D SACs) have been widely studied on the nitrogen reduction reaction (NRR). The characteristics of 2D catalysts imply that both sides of the monolayer can be catalytic sites and adsorb electrolyte ions or molecules from solutions. Overstrong adsorption of electrolyte ions or molecules on both sides of the catalyst site will poison the catalyst, while the adsorbate on one side of the catalytic site will modify the activity and selectivity of the other side for NRR. Discovering the influence of adsorption of electrolyte ions or molecules as a functional ligand on catalyst performance on the NRR is crucial to improve NRR efficiency. Here, we report this work using the density functional theory (DFT) method to investigate adsorption of electrolyte ions or molecules as a functional ligand. Among all of the studied 18 functional ligands and 3 transition metals (TMs), the results showed that Ru&F, Ru&COOH, and Mo&H2O combinations were screened as electrocatalysis systems with high activity and selectivity. Particularly, the Mo&H2O combination possesses the highest activity with a low ΔGMAX of 0.44 eV through the distal pathway. The superior catalytic performance of the Mo&H2O combination is mainly attributed to the electron donation from the metal d orbital. Furthermore, the functional ligands can occupy the active sites and block the competing vigorous hydrogen evolution reaction. Our findings offer an effective and practical strategy to design the combination of the catalyst and electrolyte to improve electrocatalytic NRR efficiency.

Operando leaching of pre-incorporated Al and mechanism in transition-metal hybrids on carbon substrates for enhanced charge storage

Operando leaching of pre-incorporated Al and mechanism in transition-metal hybrids on carbon substrates for enhanced charge storage

Synthetic disposable material derived-carbon supported NiO: Efficient hybrid electrocatalyst for water oxidation process

Anchoring electrocatalyst nanoparticles on carbon materials is a promising strategy to establish a hybrid electrocatalyst with unique structure and properties. Deriving carbon support from waste materials is an environmentally green approach. In the present study, the pyrolysis of the heterogeneous mixture containing synthetic disposal material and nickel salt yields N-doped carbon fibers-supported nickel oxide (NiO@CFs) hybrid electrocatalyst. The NiO nanoparticles are well incorporated on the porous carbon base, which has densely packed sharp-edge carbon fibers (CFs). The unique carbon structure incorporated with the NiO nanoparticles that facilitates the adsorption of electrolyte ions, rushes the transfer of electrolyte ions, and thus enhances the electrochemical activity. The as-derived carbon support maximized the electrocatalyst active sites while utilizing low electrocatalyst mass loading. Specifically, the synthetic disposable material-derived-carbon fibers supported NiO (NiO@CFs) hybrid electrocatalyst exhibited remarkably higher surface area and lower charge transfer resistance when compared to that of bare NiO. Intriguingly, the NiO@CFs hybrid electrocatalyst exhibited desirable oxygen evolution reaction (OER) performance (η = 280 mV at 10 mA cm−2) and consistent durability for a 24 h continuous run. This study emphasizes that the utilization of synthetic disposal materials for deriving carbon support is an environmentally effective methodology to incorporate/hybridize electrochemically active materials for the various electrochemical applications.

N, S co-doped activated carbon with porous architecture derived from partial poly (2, 2′-dithiodianiline) for supercapacitors

High-performance porous carbon is an essential electrode materials for high-specific energy supercapacitors because it has a high specific surface area on the electrode surface and stores charge through electrolyte-ion adsorption. In this article, N, S co-doped porous carbon was successfully prepared through carbonization and activation of partial poly (2, 2′-dithiodianiline) (PDTDA). The N, S co-doped porous carbon material was used to prepare the electrode for supercapacitor. The three-electrode system was used to test its electrochemical performance. The results show that the suitable carbonization temperature was 600 °C (ASNC-600–800), which showed excellent capacitance performance. The specific capacitance of ASNC-600–800 is 500.10 F/g at 1 A/g. In addition, N, S co-doped porous carbon possess the specific energy of 21.15 Wh/kg at specific power of 450 W/kg. A new path has been opened for the preparation of low cost and high-performance porous carbon electrode materials.