Potential Supercapacitor Research Articles

Ag-decorated ZnCo2S4/SiO2 nanocomposite as a high-performance supercapacitor electrode

Ag-decorated ZnCo2S4/SiO2 nanocomposite was utilized in this study as a potential supercapacitor electrode. Ag nanoparticles demonstrate a low level of pseudo-capacitance and their capacity to improve charge transfer. The specific capacitances of the ZnCo2S4, ZnCo2S4/SiO2, and Ag@ZnCo2S4/SiO2 electrodes were 935, 1066, and 1623 Fg−1, respectively, at 1 Ag−1 current density. The Ag@ZnCo2S4/SiO2 electrode exhibits remarkable cycle stability (100 % coulombic efficiency and capacitance retention of approximately 91.7 % at 10 A g−1 after 10,000 cycles). Furthermore, the symmetric supercapacitor (Ag@ZnCo2S4/SiO2//Ag@ZnCo2S4/SiO2) possesses a broad potential window of 1.5 V, a maximal energy density of 68.6 Whkg−1, and a specific power of 23.88 kWkg−1. Furthermore, the hybrid supercapacitor device (Ag@ZnCo2S4/SiO2//Ag@ZnCo2S4/SiO2) demonstrated a coulombic efficiency of 100 % and a capacitance retention of 92.3 %. Consequently, the Ag@ZnCo2S4/SiO2 composite electrode was suitable for high-energy supercapacitors due to their high capacitance, remarkable cycle stability, and high energy density.

Simple Nickel Foam Modification Procedures for Enhanced Ni Foam Supercapacitor Applications

The three-dimensional and porous structure of nickel foam makes it an attractive material for employment in cost-effective electrochemical supercapacitors. This communication presents ac. impedance spectroscopy and cyclic voltammetry electrochemical examinations of potential supercapacitor electrode materials, fabricated by means of simple electrochemical procedures, employed to as-received Ni foam material. This involves the electro-oxidation and Co-catalytic modifications of baseline nickel foam samples. Hence, the supercapacitor-type performance (as evidenced over the examined potential range in 0.1 M NaOH solution) of base nickel foam material could extensively be tailored by means of simple surface and catalytic refinements. The latter was evidenced through the employment of combined electrochemical (cyclic voltammetry, ac. impedance) and SEM/EDX (Scanning Electron Microscopy/Energy Dispersive X-Ray) surface spectroscopy evaluations.

Boosting of Redox-Active Polyimide Porous Organic Polymers with Multi-Walled Carbon Nanotubes towards Pseudocapacitive Energy Storage.

Redox-active porous organic polymers (POPs) demonstrate significant potential in supercapacitors. However, their intrinsic low electrical conductivity and stacking tendencies often lead to low utilization rates of redox-active sites within their structural units. Herein, polyimide POPs (donated as PMTA) are synthesized in situ on multi-walled carbon nanotubes (MWCNTs) from tetramino-benzoquinone (TABQ) and 1,4,5,8-naphthalene tetracarboxylic dianhydride (PMDA) monomers. The strong π-π stacking interactions drive the PMTA POPs and the MWCNTs together to form a PMTA/MWCNT composite. With the assistance of MWCNTs, the stacking issue and low conductivity of PMTA POPs are well addressed, leading to the obvious activation and enhanced utilization of the redox-active groups in the PMTA POPs. PMTA/MWCNT then achieves a high capacitance of 375.2 F g-1 at 1 A g-1 as compared to the pristine PMTA POPs (5.7 F g-1) and excellent cycling stability of 89.7% after 8000 cycles at 5 A g-1. Cyclic voltammetry (CV) and in situ Fourier-Transform Infrared (FT-IR) results reveal that the electrode reactions involve the reversible structural evolution of carbonyl groups, which are activated to provide rich pseudocapacitance. Asymmetric supercapacitors (ASCs) assembled with PMTA/MWCNTs and activated carbon (AC) offer a high energy density of 15.4 Wh kg-1 at 980.4 W kg-1 and maintain a capacitance retention of 125% after 10,000 cycles at 5 A g-1, indicating their good potential for practical applications.

Superficially activating strategies to elevate the supercapacitor performance of nano-cube nickel cobalt-Prussian blue

Prussian Blue Analogs (PBA) has good application potential in supercapacitors due to their unique microstructure characteristics. Nevertheless, the limited conductivity of these materials poses a significant obstacle to their widespread application as electrodes in supercapacitors. Herein, the conductivity of NiCo-PBA is enhanced through the implementation of three surface treatment methods, namely sulfidizing, selenizing and phosphating, and then the explicit electrochemical performance of NiCo-PBA was elevated. In addition, the P-NiCo-PBA//AC ASC occupies the best energy density (48.90 Wh kg−1/42.16 Wh kg−1) at a certain power density (1947.38 W kg−1/9545.10 W kg−1) compared to the NiCo-PBA//AC ASC, S-NiCo-PBA//AC ASC and Se-NiCo-PBA//AC ASC, and the specific capacitance retention rate of P-NiCo-PBA//AC ASC after 10,000 cycles is 88.25%. The phosphating strategy outperforms sulfidizing and selenizing strategies in enhancing the performance of nanocube-like NiCo-PBA supercapacitors. The accomplishment significantly broadens the potential applications of PBA-based materials as electrodes for supercapacitors.

High performance symmetric supercapacitors based on Au incorporated CrN thin films fabricated by reactive magnetron sputtering

Recently, transition metal nitrides are being investigated extensively as potential supercapacitor material. In the present study, Au incorporated CrN (Au_CrN) thin films have been synthesized using reactive magnetron co-sputtering technique for application as supercapacitor electrode material. Films have been prepared at different Ar to N2 flow rates keeping total deposition pressure constant to achieve the required structural phase in the sample. Electrochemical properties of the deposited materials have been investigated with a three-electrode system in 0.5 M H2SO4 aqueous electrolyte. The CrN thin film deposited under 3:1 Ar: N2 partial pressure or flow rate ratio shows the highest specific capacitance. Upon Au incorporation, the film shows an areal capacitance of 56.8 mFcm−2 at 1.0 mAcm−2discharge current density which is an almost nine-fold enhancement in specific capacitance value compared to pristine CrN sample. Symmetric supercapacitors have also been developed by sandwiching two identical Au_CrN thin film electrodes, which have found to deliver excellent specific capacitance of 86.03 mFcm−2at 1.0 mAcm−2 discharge current density with no decline in capacitance value till 20,000 cycles. Furthermore, it can deliver a high energy density of 52.02mWhcm−2and a power density of 0.12mWcm−2. The electrochemical properties of the supercapacitors fabricated with the Au_CrN thin film electrodes are found to be better than most of the results reported so far in the literature with CrN electrodes. Results of the present study clearly demonstrate that these Au enhanced CrN films prepared by easily scalable and highly reproducible magnetron sputtering technique have great potential as a high capacitance supercapacitor electrode material.

Self-assembled from monometallic-organic framework to bimetallic-organic framework materials with promoted supercapacitor performance

Designing new metal–organic frameworks (MOFs) materials with definite structure and introducing heterometallic atom is an effective strategy to develop new electrocatalytic and energy storage materials. Herein, one new 3D close-packed type manganese metal–organic frameworks, namely [Mn2(BPTC)(DMSO)2.5] (Mn-MOF) have been constructed from a rigid biphenylic acid with a rigid biphenyl-3,3′,5,5′-tetracarboxylic acid (H4BPTC) ligand under a solvothermal condition. Besides, adopting the metal doping strategy, a series of bimetallic MnM’-MOF (M’=Co, Ni and Cu) crystalline materials has been successfully grown on nickel foam (NF) and were used for supercapacitor electrode material. By contrast, the MnNi-MOF/NF shows a specific capacitance of 3391.7 mF cm−2 at 1 mA‧cm−2 in 1.0 M KOH, which is 1.6 times that of Mn-MOF/NF electrode. It also displays excellent cycle stability to keep 92.6 % of the initial capacity after GCD 20000 cycles. Finally, a hybrid supercapacitor (HSC) made from on the MnNi-MOF electrode and activated carbon (AC) could deliver an energy density of 0.224 mWh cm−2 at a power density of 1.04 mW cm−2, and a high cycle-to-cycle stability with 90.1 % of the primary capacitance over 20,000 cycles. This work not only confirms the potential supercapacitor properties of as-synthesized new Mn-MOF, but also effectively improves the specific capacity and device stability of pure Mn-MOF by introducing different transition metal ions.

Synthesis of reduced graphene oxide and Nickel oxide/reduced graphene oxide composite materials for supercapacitor applications and their computational investigations

This study outlines the synthesis of reduced graphene oxide (rGO) and Nickel oxide/reduced graphene oxide (NiO/rGO) composite materials without the use of binders. The synthesis method involved microwave-assisted reduction using ascorbic acid (AA) and varying weight ratios of potassium hydroxide (KOH) to convert graphene oxide (GO) to rGO. The research investigates how adjusting the weight ratios of GO and KOH influences the electrical conductivity (EC) properties of the synthesized materials, particularly exploring the impact of KOH addition on the porosity growth in the rGO layers during fabrication. Various analytical techniques, including optical, vibrational, morphological, bonding, and network analysis, were employed to characterize the synthesized materials. The materials were evaluated as potential supercapacitor electrodes using electrochemical techniques such as cyclic voltammetry and A.C. impedance analysis, including Nyquist and Bode plots. The specific capacitance (CS) of rGO and NiO/rGO was determined to be 1400 Fg−1 at a scan rate of 0.005 Vs−1. The synthesis process avoided the use of hazardous reagents. Additionally, density functional theory (DFT) based computational analysis was conducted to support the experimental findings. The study documents the influence of incorporating NiO onto the surface of GO and rGO on the energy gap (Egap) and investigates the density of state (DOS) to understand the effect of MO-rGO interaction. Furthermore, frontier molecular orbital (FMO) contours were examined to analyze excitation qualities, and electron potential was visualized and mapped onto the electron density surface to gain insights into charge dispersion within the structures.

Effect of sandblasting and acid surface pretreatment on the specific capacitance of CuO nanostructures grown by hot water treatment for supercapacitor electrode applications

Crystalline copper oxide (CuO) nanostructures with micro, nano, and micro-nano surface roughness were grown on Cu sheet substrates by a facile, scalable, low-cost, and low-temperature hot water treatment (HWT) method that simply involved immersing Cu sheet in DI water at 75 °C for 24 h without any chemical additives. Various morphological features and sizes of CuO nanostructures were tuned by using different surface pretreatment techniques including acid treatment, sandblasting, or a combination of those two. The surface morphology of the prepared samples was analyzed by scanning electron microscopy. The crystal structure of the CuO nanostructures was investigated by x-ray diffraction XRD and Raman spectroscopy. To study the pseudocapacitive behavior, their potential supercapacitor performance, and equivalent series resistance, electrochemical analysis was done by cyclic voltammetry and electrochemical impedance spectroscopy for all the CuO/Cu samples in 1 M of Na2SO4 electrolyte. Among all, the best supercapacitive performance was achieved for CuO/Cu samples pretreated with Sandblasting followed by Acid treatment resulting in a specific capacitance of about 104 F g−1. The electrode with the sandblasted + acid pretreated sample showed a maximum of ∼69% capacitive retention after 2000 consecutive cycles. Our results indicate that CuO nanostructures on Cu substrates prepared with different surface pretreatment conditions and grown by HWT can be promising electrodes for supercapacitor device applications.

Investigations on supercapacitor performance of novel ZnO-CeO2-rGO nanohybrid prepared via hydrothermal method for energy storage applications and their charge storage mechanism

Nanohybrids which can utilize the synergistic effect to enhance the electrochemical activity as an electrode material for supercapacitor has gained immense interest recently.Here,we report a ZnO-CeO2-rGO ternary nanohybrid synthesized via hydrothermal method which can combine the pesuedocapacitance nature of transition metal oxide and electric double layer behavior of reduced graphene oxide. The electrochemical activity was thoroughly investigated using cyclic voltammometry(CV) and galvanostatic charge discharge for the ternary using a two electrode set up with 2 M KOH as the electrolyte. Cyclic stability analysis was done and impedance analysis was carried out using electrochemical impedance spectroscopy. Among the samples the best electrochemical performance was observed for ZnO –CeO2-rGO (Ter-2) with weight ratio 85:10:5. Ter-2 exhibited specific capacitance of 26 F/g from CV in the 2-electrode setup and a capacity retention as high as 93 % even after 5000 cycles of charge-discharge. It was observed that the addition of rGO improved the cyclic stablity as well as specific capacitance. Systematic analysis of charge storage mechanism was done using Dunn's and Trasatti's method. The results substantiate that Ter-2 is a potential supercapacitor electrode material with excellent electrochemical activity.

Experimental and theoretical studies on cobalt ruthenium phosphate structure optimization towards supercapacitor application

Recent studies have given indications that nanoarchitectured binary transition metal phosphates can act as potential supercapacitor (SC) electrode materials due to their exceptional energy storage capacity and remarkable electrochemical stability. However, the highly amorphous nature or broad X-ray diffraction peaks of metal phosphates put a limit on the structural optimization of these materials. We demonstrate a combined experimental and theoretical study leading to an optimized cobalt-ruthenium phosphate (CRP) structure for high-performance SC application. The material structure was optimized by detailed density functional theory (DFT) calculations, including the Bader charge analysis, DOS, and PDOS, revealed the lattice and volume expansion, reduced band gap, and improved conductivity of the cobalt phosphate lattice by including ruthenium in the cobalt phosphate. These predictions are verified with experimental band gap and high-resolution transmission electron microscope plane image indexing. Further, the CRP was developed by potentiostatic deposition onto the carbon cloth substrate. The flexible CRP electrode exhibited a high specific capacitance of 1258 F g−1 (943.5C g−1) in the aqueous 2 M KOH electrolyte. The asymmetric SC device (CRP//activated carbon) has exhibited an excellent specific energy of ∼59 Wh kg−1 at a specific power of ∼751 W kg−1.

Dealloyed nickel skeleton hosting in-situ formed multimetallic phosphides for enhanced electrochemical energy storage

Transition metal phosphides (TMPs) exhibit considerable potential in supercapacitors (SCs) electrodes fabrication due to their high power densities and conducive ion transport, positioning them as quintessential candidates for such application. Despite their promise, monometallic phosphides require further electrochemical performance enhancements. This work unveils an innovative strategy for synthesizing complex cobalt/nickel phosphides directly on a nickel skeleton (Ni@NCP), achieved by the selectively leaching copper from a Ni–Cu alloy via a dealloying process after electrodeposition, significantly improving electrochemical performance through increased electroactive sites and optimized ion diffusion channels. The Ni@NCP electrode exhibits an impressive specific capacitance of 612 F g−1 at a high current density of 20 A g−1. Furthermore, the unique hollow nanotube structure greatly enhances cyclic stability, maintaining 80.1 % capacity after 10,000 cycles at 10 A g−1. This research presents a methodical approach to electrode material synthesis, emphasizing the construction of supportive frameworks and active sites, thereby underscoring the substantial potential for advancements in SC electrode technology.

Magnetron Sputtered SnO₂ Layer Combined with NiCo−LDH Nanosheets for High‐Performance All‐Solid‐State Supercapacitors

AbstractNickel‐cobalt layered double hydroxide (NiCo−LDH) has attracted much attention because of its excellent electrochemical properties and regulability. And it is a potential pseudocapacitive electrode material, which is commonly used in supercapacitors and lithium‐ion batteries. Its application in the field of supercapacitors can improve the energy density, power density and cycle life of devices. However, NiCo−LDH still faces some challenges, such as poor electrical conductivity and the capacity attenuation caused by agglomeration of layered structures, which require further research and optimization. In this paper, SnO2 films were prepared on carbon cloth (CC) by magnetron sputtering method, and Ni−Co LDH nanosheets were grown by hydrothermal reaction to obtain NiCo−LDH@SnO2 composites. Due to the synergistic effect between NiCo−LDH and SnO2, NiCo−LDH@SnO2 composites exhibit high Cs and good cyclic stability. In addition, an all‐solid‐state flexible asymmetric supercapacitor (ASC) was assembled with activated carbon (AC) anodes, showing good specific capacitance(Cs) and energy density. And a high initial capacitance can still be retained after 10,000 cycles. This paper shows that NiCo−LDH@SnO2 shows excellent application potential in supercapacitors.

Light-Induced Self-Assembled Polydiacetylene/Carbon Dot Functional "Honeycomb".

The design of functional supramolecular assemblies from individual molecular building blocks is a fundamental challenge in chemistry and material science. We report on the fabrication of "honeycomb" films by light-induced coassembly of diacetylene derivatives and carbon dots. Specifically, modulating noncovalent interactions between the carbon dots, macrocyclic diacetylene, and anthraquinone diacetylene facilitates formation of thin films exhibiting a long-range, uniform pore structure. We show that light irradiation at distinct wavelengths plays a key role in the assembly process and generation of unique macro-porous morphology, by both initiating interactions between the carbon dots and the anthraquinone moieties and giving rise to the topotactic polymerization of the polydiacetylene network. We further demonstrate utilization of the macro-porous film as a photocatalytic platform for water pollutant degradation and as potential supercapacitor electrodes, both applications taking advantage of the high surface area, hydrophobicity, and pore structure of the film.

Engineered nano-architecture for enhanced energy storage capabilities of MoS2/CNT-heterostructures: A potential supercapacitor electrode

Hydrothermal synthesis was utilized to achieve the direct growth of molybdenum disulphide (MoS2) nanoflakes on carbon nanotubes (CNT). Through this method, MoS2/CNT heterostructures with engineered microstructure have been obtained by suitably optimizing the synthesis conditions. Raman, X-ray photoelectron spectroscopy, and electron microscopy have been utilized to characterize the heterostructure. The present study investigated the influence of varying amounts of CNT and MoS2 within the heterostructure on its electrochemical properties. The optimization of the heterostructure morphology has resulted in enhanced electrochemical performance, with a high specific capacitance of ∼436 F/g at 1 A/g, along with good rate capability. The charge storage mechanism was explained by using Dunn's power law. Further, the MoS2/CNT heterostructure was employed to fabricate a solid-state symmetric supercapacitor. The device exhibited a specific capacitance of ∼164 F/g at 1 A/g, along with good cyclic stability, retaining 96 % of its capacitance after 1000 cycles. Additionally, the device demonstrated high energy and power density values of ∼27 Wh/Kg and 603 W/Kg, respectively. The present study indicates that the MoS2/CNT heterostructure holds great promise as an electrode material for high-performance solid-state supercapacitor devices.

Electrochemical Synthesis of Functionalized Graphene/Polyaniline Composite Using Two Electrode Configuration for Supercapacitors.

An effective approach for the large-scale fabrication of conducting polyaniline (PANI) using in situ anodic electrochemical polymerization on nickel foam which had been coated in aryl diazonium salt (ADS)-modified graphene (ADS-G). In the present work, ADS-G was used as a high surface-area support material for the electrochemical polymerization of PANI. The electrochemical performances of the ADS-G/PANI composites exhibited better suitability as supercapacitor electrode materials than those of the PANI. The ADS-G/PANI composites achieved a specific capacitance of 528 F g-1, which was higher than that of PANI (266 F g-1) due to excellent electrode-electrolyte interaction and the synergistic effect of electrical conductivity between ADS-G and PANI in the composites. These findings suggest that the ADS-G/PANI composites are a suitable composite for potential supercapacitor applications.

Unveiling the potential of PANI@MnO2@rGO ternary nanocomposite in energy storage and gas sensing

The development of advanced materials for energy storage and gas sensing applications has gained significant attention in recent years. In this study, we synthesized and characterized PANI@MnO2@rGO ternary nanocomposites (NCs) to explore their potential in supercapacitors and gas sensing devices. The ternary NCs were synthesized through a multi-step process involving the hydrothermal synthesis of MnO2 nanoparticles, preparation of PANI@rGO composites and the assembly to the ternary PANI@MnO2@rGO ternary NCs. The structural, morphological, and compositional characteristics of the materials were thoroughly analyzed using techniques such as XRD, FESEM, TEM, FTIR, and Raman spectroscopy. In the realm of gas sensing, the ternary NCs exhibited excellent performance as NH3 gas sensors. The optimized operating temperature of 100 °C yielded a peak response of 15.56 towards 50 ppm NH3. The nanocomposites demonstrated fast response and recovery times of 6 s and 10 s, respectively, and displayed remarkable selectivity for NH3 gas over other tested gases. For supercapacitor applications, the electrochemical performance of the ternary NCs was evaluated using cyclic voltammetry and galvanostatic charge-discharge techniques. The composites exhibited pseudocapacitive behavior, with the capacitance reaching up to 185 F/g at 1 A/g and excellent capacitance retention of approximately 88.54% over 4000 charge-discharge cycles. The unique combination of rGO, PANI, and MnO2 nanoparticles in these ternary NCs offer synergistic advantages, showcasing their potential to address challenges in energy storage and gas sensing technologies.

Promoted OH– adsorption and electron-transfer kinetics by electrospinning mono-disperse NiCo2S4 nanocrystals within porous CNFs for solid asymmetric supercapacitors

Bimetallic sulfide NiCo2S4 has been regarded as a potential supercapacitor electrode material with excellent electrochemical performance. However, the origin of its high specific capacity is little studied, and the design of a rational structure still remains a challenge to exert its intrinsic advantage. In this work, the advantage of NiCo2S4 over NiS and CoS is explained by density functional theory calculation from the aspects of energy band, density of electronic states and OH– adsorption energy. It is proved that the synergistic effect of Ni and Co in NiCo2S4 can reduce its OH– adsorption energy and provide more active electrons near the Fermi level, thus promoting electrochemical reaction kinetics in supercapacitors. Then, a simple electrospinning method is used to in-situ load mono-disperse NiCo2S4 nanocrystals within amorphous carbon nanofibers, obtaining a porous, lotus-leaf-stem-like one-dimensional nanocomposite of NiCo2S4/CNF. Ex-situ XPS characterization confirms that the proportion of metal ions involved in electrochemical reactions and the number of transferred electrons in NiCo2S4/CNF during the redox reaction are significantly higher than those in mono-metallic sulfides (NiS/CNF and CoS/CNF), verifying the calculation results. With its boosting reaction kinetics, the NiCo2S4/CNF gives the specific capacity of 757.97C g−1 at 1 A/g and the capacity retention of 95.15 % after 10,000 cycles at 5 A/g, both greater than NiS/CNF and CoS/CNF. The NiCo2S4/CNF, as the positive electrode, and activated carbon, as the negative electrode, are assembled into liquid-state and solid-state asymmetric supercapacitor (ASC) devices, and both show high power density (760.6 W kg−1 for liquid-state device and 1067.4 W kg−1 for solid-state device), high energy density (52.25 Wh kg−1 for liquid-state device and 48.54 Wh kg−1 for solid-state device) and great cycle stability. Moreover, the solid-state ASC device possesses excellent low temperature capacity and reversibility, further demonstrating the wide application potential of the NiCo2S4/CNF composite.

Self-standing porous MXene film via in situ formed microgel induced by 2- methylimidazole for high rate supercapacitor

Ti3C2Tx MXene has been considered a potential supercapacitor electrode material on account of its fast electron transfer performance, large volume pseudocapacitance, excellent hydrophilicity and mechanical properties. However, the serious stacking of MXene nanosheets reduced the exposed active sites and hindered diffusion of ions, leading to bad electrochemical property. Here, we report a strategy to transform MXene nanosheets into 3D MXene microgels induced by 2-methylimidazole. Benefitting from the existence of microgels, it facilitates the rapid vacuum filtration to prepare the porous MXene film, thus enhancing the ion transfer efficiency. Furthermore, 2-methylimidazole can also act as an intercalated agent to increase the layer spacing of MXene nanosheets. Therefore, the as-prepared porous MXene film demonstrates a superior rate capacity, and its capacitance reaches 223.4 F g−1 at the scan rates of 1000 mV s−1. Moreover, the assembled MXene//AC asymmetrical supercapacitor displays a 16.88 Wh kg−1 at a power density of 799 W kg−1, and maintains 13.11 Wh kg−1 at a power density of 8 kW kg−1. This work develops a simple way to prepare the porous MXene film for supercapacitors with excellent electrochemical performance.

Fabrication of an efficient hierarchical mesoporous 2D-MoS2/CNT/polypyrrole based composite electrodes for competitive and selective U6+ removal using capacitive deionization: Mechanistic evaluation through cyclic voltammetry

In this work, efficient and selective carbonaceous electrode materials based on hierarchical mesoporous functionalized carbon nanotubes, 2D-MoS2 nanosheets electrodeposited with variable content of polypyrrole (PPy) were prepared. The simple etching reaction between HNO3 and carbon nanotubes did not only modify the surface but also improved its hydrophilicity. The annealing of carbon nanotubes and electrodeposition of PPy increased the mesopore volume to total volume ratio (Vmeso/Vt) from 0.42 to 0.86. The composite materials were characterized wisely using different characterization techniques and employed for efficient U6+ electro-assisted sorption through capacitive deionization. Electrode material with PPy content (0.3 M) exhibited good specific capacitance Csp (100.2 F/g), improved Vmeso (0.61 cm3/g), superb Vmeso/Vt ratio (0.86) and large specific surface area SBET (149.7 m2/g). The stated electrode showed fast sorption kinetics (teq=30 min), admirable selectivity and exhibited the experimental sorption capacity of 274.50 mg/g at − 0.90 V. Electrochemical impendence spectroscopic study revealed that the resulting material exhibited relatively small charge transfer resistance (1.19 Ωcm2), minute electrolytic resistance (0.91 Ωcm2) and large double layer constant phase element (0.0368 S sn/ cm2). These significant characteristics promoted U6+ ions diffusion inside the hierarchical porous electrode surface for better performance of electrosorption process. This new class of hierarchical mesoporous composite electrodes may be used as potential supercapacitor materials not only for removal of uranium but also for other potent desalination applications.

Tubular Cu2MoS4/MWCNTs as supercapacitor negative electrode material

The ternary layered Cu2MoS4 (CMS) has been proven to be a potential supercapacitor negative electrode material. However, its inherent low conductivity and limited diffusion dynamics usually result in unsatisfactory specific capacitance and rate performance. Therefore, hollow tubular CMS and CMS/MWCNTs-0.05, 0.15, 0.25 composite materials were prepared by a one-pot hydrothermal method in this work. The addition of MWCNTs improves the electrical conductivity and provides an efficient three-dimensional electronic transport network. Due to the smallest resistance and optimized porous structure with large surface area, CMS/MWCNTs-0.15@CC exhibits a highest specific capacitance (Cs) of 219F g−1 at 0.5 A g−1, which is 2.45 times that of CMS@CC. The assembled Ni-Co-S@CC//CMS/MWCNTs-0.15@CC supercapacitor with a voltage window of 1.8 V yields a maximum energy density of 24.5 Wh kg−1 at 900 W kg−1.