Anion-exchange Technique Research Articles

Structural characterization, physicochemical properties and hypoglycemic activity of soluble dietary fibers from salt stressed mung bean sprouts

Low-salt stress germination is an effective way to improve the nutritional composition of food crops. A novel soluble dietary fiber (MS-SDF) was isolated from low-salt stress mung bean sprouts that were exposed to low-salt stress using anion exchange and gel permeation techniques. Structural analysis revealed that MS-SDF was a homogeneous heteropolysaccharide with an average molecular weight of 164.997 KDa. It featured a loose structure and contained the characteristic functional groups typical of polysaccharides. MS-SDF was composed of arabinose, galactose, glucose, and mannose with a molar ratio of 3.95:3.86:82.69:9.02. The structure was mainly composed of →6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,6)-α-D-Glcp-(1→ as the main chain. Branched at O-3 position with single β-D-Manp-(1→ as major the side chain. Furthermore, in vitro hypoglycemic assays indicate that MS-SDF exhibits α-glucosidase inhibitory activity, significantly enhancing glucose uptake, glycogen synthesis, and pyruvate kinase activity in insulin-resistant HepG2 cells. Overall, MS-SDF could be used as a promising source of functional hypoglycemic foods.

Preparation of ionic liquid-immobilized siloxane membranes by vapor-phase transport and anion exchange

Using the sol-gel method, we developed ionic liquid (IL)-immobilized siloxane membranes from ionic alkoxysilanes (silylated ILs). The developed membranes were adapted for the separation of inorganic and organic gases and organic liquid mixtures. In this study, we developed a new method for preparing IL-immobilized siloxane membranes using vapor-phase transport and anion exchange techniques. First, a siloxane membrane containing chloropropyl groups was prepared in a porous Al2O3 tube. The membrane was brought into contact and reacted with 1-methylimidazole vapor at 353 K. AgCl precipitation, and Cl 2p3/2 X-ray photoelectron spectroscopy revealed that the chloropropyl group was successfully converted into an imidazolium-type IL structure. Next, the membrane was immersed in aqueous HN(SO2CF3)2 to exchange the anion from Cl− to (CF3SO2)2N−. The change in permselectivity through the membranes before and after the vapor-phase transport and anion-exchange treatments was confirmed by steam/H2 and toluene/N2 separation tests. The developed techniques exhibit excellent potential for preparing a wide variety of IL-immobilized siloxane membranes.

Zinc Layered Hydroxide 2-methyl-4-chlorophenoxyacetate: Synthesis via ZnO, Characterization and Effect on Seed Germination

2-methyl-4-chlorophenoxyacetic acid (MCPA) was successfully intercalated into zinc layered hydroxide (ZLH) by anion exchange technique followed by hydrothermal treatment, resulting in the formation of nanoherbicide, zinc-layered hydroxide-2-methyl-4-chlorophenoxyacetic acid (ZMCPA). Fourier-transform infrared spectroscopy (FTIR) and Powder X-ray diffraction (PXRD) was used to confirm the intercalation of herbicide into ZLH, while Ultraviolet-visible spectroscopy (UV-vis) was employed to assess the plant’s protein content and amino acid composition before and after 1 h treatment with ZnO, MCPA and ZMCPA via the foliar technique and direct soil application. The basal spacing of ZMCPA in this study is 21.6 Å at 4.0815°, revealing the triumphant incorporation of MCPA into the ZLH host. The zinc oxide (ZnO) fingerprint from 30° to 60° that certainly vanished in the ZMCPA diffractogram indicates that all ZnO has successfully converted to ZLH matrices. The FTIR spectrum of ZMCPA shows the similarity of most MCPA spectra, but with the COO– peaks at 1610 and 1700 cm–1 replacing the intense C=O band at 1742.21 cm–1, implying that the herbicide has assimilated into the host. The protein level of the plant treated with ZMCPA was discovered to be more significant, which signifies that ZLH has effectively acted as a herbicide carrier. This study has depicted the potential of ZMCPA as a more unassailable agrochemical agent in increasing crop productivity while minimizing environmental consequences. HIGHLIGHTS Successful Intercalation of MCPA into Zinc Layered Hydroxide (ZLH) Enhanced Plant Protein Levels with nanocomposite, ZMCPA Treatment ZMCPA as a potentially more effective and environmentally friendly agrochemical agent compared to the traditional agrochemical GRAPHICAL ABSTRACT

Air-Stable Semiconducting Ionic Polymers for Thermoelectric Applications

Thermoelectric (TE) devices that interconvert heat and electricity are the promising tools to harvest waste heat and solve energy problems. The current TE market is dominated by inorganic materials such as Bi2Te3 due to their excellent TE performance; however, the issues of inorganics that involve material toxicity, rigidity, heavy weight and energy-intensive processing techniques are limiting the wide applications of TE devices. Choosing organic materials that are light weight, mechanically flexible, abundant and require low-temperature processing, as in our research focus, is paving the path to sustainability and opening up opportunities for a variety of applications such as electronic wearables and sensors.In our study, we aim to design and develop sensors that can detect high electric-field utilizing air-stable ionic polymer TE systems, a novel type of organic semiconductors, via a facile, solution-processing technique. We selected two n-type chloride-based ionic polymers, MADQUAT and PDADMAC as our starting materials because they have relatively low yet reliable ionic conductivities and intrinsically high Seebeck Coefficients under dry condition. The key challenge was that chloride-based polymers were extremely unstable due to their sensitivity to air/moisture and polymer relaxation. We adopted a solution-processable anion exchange technique and successfully created new systems with the same cationic polymer chain but various anions such as tetrafluoroborate (BF4 -) and hexafluorophosphate (PF6 -), that are more hydrophobic, increasing the system stability. Currently, we are investigating our stable ionic polymer TE performance by applying high voltages (500V-2000V) laterally across the samples through a pair of electrodes thermally evaporated on top. The change in TE properties after the high E-field application will help us probe further into the ionic movement of the polymeric systems thermodynamically and kinetically and understand what determines the p/n-type behavior. The thermoelectric sensor for high E-field detection can be incorporated into devices that can detect planetary objects in the outer space as well as microscale biological systems.

SPECTRAL AND PHOTOPHYSICAL CHARACTERISTICS OF ASYMMETRIC POLYMETHINE DYES IN POLYURETHANE MATRICES

Here the composite polymer sorbent hydrogels were synthesized by in situ technique via free radical polymerization of acrylamide (AAm), 2-hydroxyethyl methacrylate (2HEMA) and N,N’-methylene-bis(acrylamide) crosslinker mixture in the presence of as-prepared dispersion of nickel-aluminum layered double hydroxide (NiAl-LDH). A content of active NiAl-LDH filler in the polymer matrix was varied in a range of 30 – 70 wt.%. It was found a high filler content suppresses a molecular mobility of copolymer matrix chains and reduces a beginning of glass transition temperature of the polymer constituent. The results of thermal analysis of polymer composites demonstrate a high hydrophilicity level of polymer matrix and high solvation energy of polar functionalities by Н2О molecules that was concluded from slow moisture elimination process while the temperature grows up to 200–210 оС. Additionally, a dehydration process and changes in a structure of thermally labile filler were also observed at the same temperature interval. At higher temperatures a thermal degradation of polymer poly(AAm-co-2HEMA) matrix is carried out. When a temperature overcomes 400 оС the partially changed filler demonstrates a chemical interaction with degraded organic constituents of the composites and defined catalytic activity as well. Studying sorption activity of the composites shown that introducing NiAl-LDH into hydrophilic polymer matrix provides anion-exchange activity to the composite sorbents and, correspondingly, the ability to eliminate the anionic contaminants from aqueous media while the polymer matrix doesn’t absorb these substances at such conditions. The highest sorption capacity of 11,40 μmol/g against model contaminant – methyl orange dye was determined for composite sorbent with filler content of 70 wt. %. At the same time sorption capacity of NiAl-LDH filler in composite sorbents reduces from 25,7 to 16,6 μmol/g while a filler content grows from 30 to 70 wt.% as a result of filler particles aggregation processes during composites formation stage. To evaluate the ability of the composite sorbents to reuse the experiment of materials recycling was performed. It was stated out the using of anion-exchange technique and aqueous Na2CO3 solution as an efficient and non-hazardous eluent provides 80 % recovering efficiency of the active filler in the composites. It can be concluded the composite sorbents demonstrate a high overall efficiency and are valuable materials for practical application for decontamination of waste water.

Novel design and synthesis of multi-anionic Co(OH)Se with ZIF-67 derived porous carbon matrix as a bifunctional electrocatalyst for rechargeable Zn-air batteries

Multi-anionic transition metal compounds with unique electron structures that are favorable for electron transfer are promising oxygen electrocatalysts. In this study, to synthesize a bifunctional oxygen electrocatalyst for Zn-air batteries (ZABs), unique structured composite of cobalt hydroxy selenide (Co(OH)Se) and nitrogen-doped carbon (C) was fabricated using a novel water vapor-assisted heat-treatment and an anion-exchange technique using a NaHSe solution. C@Co(OH)Se prepared under low-temperature and low-pressure condition successfully exhibited excellent electrocatalytic activities for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) via synergistic effects. Accordingly, C@Co(OH)Se-based ZAB displayed great cycle stability (discharge/charge potential gap of 1.01 V after 7,000 min cycling) and rate capability (1.25 V at 15 mA cm−2). By first demonstrating the potential use of multi-anionic Co(OH)Se as a bifunctional electrocatalyst for the ORR/OER and presenting a technique for complexing transition metal compounds and carbon matrices, our study expands the range of electrocatalyst design and synthesis.

Designing n-type all-ionic thermoelectric polymers with improved air stability via a solution-processing anion exchange technique

We replaced Cl− ions with bulkier BF4 and PF6− in ionic thermoelectric polymers. BF4−-MADQUAT and PF6−-PDADMAC showed good ionic conductivity and reliable, reproducible Seebeck coefficients at 40% humidity and better air stability.

Bioanalysis of Oligonucleotide by LC–MS: Effects of Ion Pairing Regents and Recent Advances in Ion-Pairing-Free Analytical Strategies

Oligonucleotides (OGNs) are relatively new modalities that offer unique opportunities to expand the therapeutic targets. Reliable and high-throughput bioanalytical methods are pivotal for preclinical and clinical investigations of therapeutic OGNs. Liquid chromatography-mass spectrometry (LC-MS) is now evolving into being the method of choice for the bioanalysis of OGNs. Ion paring reversed-phase liquid chromatography (IP-RPLC) has been widely used in sample preparation and LC-MS analysis of OGNs; however, there are technical issues associated with these methods. IP-free methods, such as hydrophilic interaction liquid chromatography (HILIC) and anion-exchange techniques, have emerged as promising approaches for the bioanalysis of OGNs. In this review, the state-of-the-art IP-RPLC-MS bioanalytical methods of OGNs and their metabolites published in the past 10 years (2012-2022) are critically reviewed. Recent advances in IP-reagent-free LC-MS bioanalysis methods are discussed. Finally, we describe future opportunities for developing new methods that can be used for the comprehensive bioanalysis of OGNs.

Polymeric ionic liquid forms of PEI microgels as catalysts for hydrogen production via sodium borohydride methanolysis

• Ionic liquid (IL) forms of polyethyleneimine (PEI) as metal free catalyst for H 2 . • NaBH 4 methanolysis via PEI-X (X:Anion) catalyst for green H 2 production. • Highly reusable IL colloidal polymeric catalyst with low Ea in H 2 generation. • Green energy carrier, H 2 release from NaBH 4 via highly regenerable PEI-X catalyst. Ionic liquid (IL) forms of polyethyleneimine (PEI) microgels were prepared using anion exchange and direct acid treatment techniques employing tetrafluoroborate (TFB) and hexafluorophosphate (HFP) anions as well as their corresponding acids, tetrafluoroboric acid (TFBA) and hexafluorophosphoric acid (HFPA), respectively. Then, these polymeric ionic liquids (PIL) of PEI microgels were used as metal-free catalysts for hydrogen (H 2 ) production from sodium borohydride (NaBH 4 ) solution in methanol (methanolysis). The parameters affecting H 2 production rates such as the types of anions, the methods of PIL preparation, temperature, reusability, and regeneration of PEI-based microgels were investigated. In the dehydrogenation reaction of NaBH 4 in methanol catalyzed by PEI-based PIL microgels, the lowest Ea value in the temperature range of −10–40 °C was calculated as 16.0 ± 0.8 kJ/mol for PEI-HFP PIL microgel, prepared by anion exchange method. The reusability studies of PEI-TFB PIL microgels revealed that the catalytic activity was decreased to 89 ± 5% after 5 consecutive use with 100% conversions for every use. Additionally, independent of the anion exchange methods, PEI-based PIL microgels afford catalytic H 2 production from NaBH 4 methanolysis in a wide range of temperatures including subzero temperatures with facile regenerations by the treatments with TFBA and HFPA resulting in 100% recovery of catalytic activities at each regeneration. The metal-free PIL form of PEI microgel catalyst renders much better catalytic performances and advantages than metal nanoparticle-based catalysts for green H 2 production offering viable alternatives in industrial application.

Use of batch anion exchange technique for separation of κ-casein glycomacropeptide from bovine whey fraction.

Bovine κ-casein glycomacropeptide (GMP) is a sialic acid containing glycopeptide, which is considered as a health promoting compound found in cheese whey. The study described in this research communication was undertaken to determine whether GMP with undetectable level of contaminating protein or phenylalanine can be isolated from bovine whey fraction using batch anion exchange technique with chitin as an adsorbent. A soluble whey fraction (SWF) prepared from 1 g whey protein isolate (WPI) was mixed with a slurry of 1 g chitin, and the mixture was incubated at pH 3.0. After incubation, the mixture was filtered, and the residue obtained (containing chitin-GMP complex) was washed with water and eluted stepwise with 0.5 M NaCl and 2.0 M NaCl. Most of GMP (corresponding to 75.8% of total sialic acid recovered) was eluted with 0.5 M NaCl. The recovered GMP accounted for 5.4% dry weight of WPI (or 18.9% dry weight of SWF). Amino acid analysis showed that there was no detectable level of contaminating amino acids including phenylalanine, histidine, arginine and tyrosine in the GMP fraction. It was concluded that the batch anion exchange method with chitin developed in this study can be used for the isolation of high purity GMP from bovine SWF.

Fabrication of REVO4 films via sacrificial conversion from layered rare-earth hydroxide (LRH) films: the investigation of the transition mechanism and their photoluminescence.

Rare-earth orthovanadate REVO4 (RE = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, and Y) films were directly synthesized within 2 hours by sacrificial conversion from electrodeposited layered rare-earth hydroxide (RE2(OH)5NO3·nH2O) films at pH ∼ 10, without subsequent heat treatment. Detailed characterization of the products was achieved by combined X-ray diffraction, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and photoluminescence excitation and photoluminescence. The mechanisms of phase and morphology evolution from Y2(OH)5NO3·nH2O to YVO4 were unveiled through systematic investigations into the influences of the concentration of the anion sources (Na3VO4) and the reaction temperature. The effects of lanthanide contraction on the phase structure and particle morphology of the REVO4 films were also clarified. Additionally, the photoluminescence of RE3+ activators (RE = Eu, Dy, and Eu and Dy) was elaborated with YVO4 as a representative host lattice, and the color-tunable emission and energy transfer from Dy3+ to Eu3+ were also investigated. Electrodeposition combined with a hydrothermal anion exchange technique established in this study led to the rapid synthesis of REVO4 films, and it might have wide implications for the generation of other types of inorganic functional films.

TETRABUTYLAMMONIUM DODECYL SULFATE: ION EXCHANGE SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITY IN COMPARISON OF SODIUM DODECYL SULFATE

A surface-active ionic liquid, tetrabutylammonium dodecyl sulfate was obtained from tetrabutylammonium bromide by employing anion exchange technique, an alternative novel approach giving 87.72 % yield and about 99 % exchange. The infrared spectroscopy coupled with prescribed tests for detection of anions confirmed the success of anion exchange. Differential Scanning Calorimetry was used for thermal characterization of the compound. A comparative profile of the physicochemical properties of three compounds viz. tetrabutylammonium dodecyl sulfate, tetrabutylammonium bromide and sodium dodecyl sulfate was created. The sodium free ionic liquid reported in this paper shows superior activity against Candida albicans at concentrations above 100 μg.

Sweet-Tasting Ionic Conjugates of Local Anesthetics and Vasoconstrictors.

Local anesthetics are widely utilized in dentistry, cosmetology, and medicine. Local anesthesia is essential to providing a pain-free experience during dental and local surgeries as well as cosmetic procedures. However, the injection itself may produce discomfort and be a source of aversion. A novel approach toward the taste modulation of local anesthetics is proposed, in which the anesthetics of the “-caine” family serve as cations and are coupled with anionic sweeteners such as saccharinate and acesulfamate. Ionic conjugates of vasoconstrictor epinephrine such as epinephrine saccharinate and epinephrine acesulfamate have also been synthesized. Novel ionic conjugates were developed using anion exchange techniques. Reported compounds are sweet-tasting and are safe to use both topically and as injections.

Synergistic anti-cancer activity of etoposide drug loaded calcium aluminium layered double hydroxide nanoconjugate for possible application in non small cell lung carcinoma

The present research reports a facile synthesis of bare phase pure CaAl-LDH nanoparticle (sample A) and intercalation of anti-cancer drug etoposide (ETO) into the same via simple anion exchange technique to obtain ETO loaded CaAl-LDH (sample B). The basal spacing (d002) of sample A was increased from 8.5764 Å to 17.18 Å upon intercalation of ETO. Further ETO loading was found to be 27.72% as estimated by UV–Vis spectrophotometer. The release profile of ETO from sample B in phosphate buffer saline (PBS) at pH 7.4 follows quasi-Fickian diffusion phenomenon in Korsmeyer–Peppas kinetics model. In vitro cell viability was undertaken using A549 (human lung adenocarcinoma) cell line in a dose dependent manner to determine the synergistic anti-cancer potential of sample B. It was observed that at an equivalent dose, the cancer cell viability was substantially reduced, in case of sample B compared to sample A and bare etoposide drug, respectively, which was further corroborated by cell proliferation/migration assay. The cellular uptake using A549 cell line showed an increasing trend with increasing time period (11.67% and 19.30% at 24 h and 72 h) respectively, confirmed by flow cytometry, exhibiting a substantial reduction of CAMKIIα protein for sample A and sample B to 110.52 pg/ml and 95.14 pg/ml respectively. Results also showed significant down regulation of SOD gene activity. All the above results exhibited the synergistic anti-cancer potential of sample B for possible application in the management of non small cell lung carcinoma (NSCLC).

Production and characterization of thermo-, halo- and solvent-stable esterase from Bacillus mojavensis TH309

The use of enzymes in many industrial applications has gained increasing importance in recent years due to their non-toxic, specific, and eco-friendly characteristics. However, two main reasons limiting their use in industry are production costs and instability under harsh conditions. We isolated thermophilic and halo-tolerant/halophilic bacteria from bio-deteriorated plastic waste. Among them, Bacillus mojavensis isolate TH309 exhibited excellent esterase secretion ability. Esterase production on sunflower seed meal increased approximately 20-fold (80.43 U/gds) with optimization of solid state medium using Plackett Burman design and response surface methodology Box Behnken design. The enzyme (BmEST) was purified 7.82-fold using ultrafiltration and anion-exchange techniques. The molecular weight of BmEST was estimated to be 30 kDa. BmEST demonstrated an optimal temperature and pH of 80 °C and 8.0, respectively, and was remarkable stable at 60–90 °C. BmEST exhibited high activity and stability in the presence of NaCl (5–20%). Furthermore, it was hyper-activated by n-pentane, acetone, hexane, DMSO, methanol, and ethanol. The apparent Km and Vmax values of BmEST were 1.28 mM and 23.88 µmol/min, respectively, with p-nitrophenol butyrate as a substrate. The enzyme caused a mass loss of poly(ε-caprolactone) films of 44% after 12 h hydrolysis. As a result, BmEST, with remarkable functional properties, presents a promising candidate to meet the needs of certain harsh biotechnological applications.

High-Quality All-Inorganic Perovskite CsPbBr3 Quantum Dots Emitter Prepared by a Simple Purified Method and Applications of Light-Emitting Diodes

High-quality perovskite CsPbBr3 quantum dots (QDs-CsPbBr3) were prepared using the ultrasonic oscillation method, which is simple and provides variable yield according to requirements. The emission spectra over a large portion of the visible spectral region (450–650 nm) of QD-CsPbX3 (X = Cl, Br, and I) have tunable compositions that can be halide exchanged using the halide anion exchange technique and quantum size-effects. A strong peak with high intensity of (200) lattice plane of purified QDs-CsPbBr3 film is obtained, confirming the formation of an orthorhombic perovskite crystal structure of the Pnma space group. The photoluminescence of QDs-CsPbBr3 was characterized using a narrow line-width emission of 20 nm, with high quantum yields of up to 99.2%, and radioactive lifetime increasing to 26 ns. Finally, through the excellent advantages of QDs-CsPbBr3 mentioned above, purified perovskite QDs-CsPbBr3 as an active layer was utilized in perovskite quantum dot light-emitting diodes structure applications. As a result, the perovskite QDs-CsPbBr3 light-emitting diodes (LEDs) exhibits a turn-on voltage of 7 V and a maximum luminance of 5.1 cd/m2.

BiOI/BiVO4 Two-Dimensional Heteronanostructures for Visible-Light Photocatalytic Degradation of Rhodamine B

By virtue of the facile anion-exchange technique, smart BiOI/BiVO4 two-dimensional (2D) heteronanostructure (HNS) photocatalysts targeted for the degradation of organic pollutants have been developed by the in situ growth of BiVO4 on the scaffolds of BiOI nanoplates. The as-obtained BiOI/BiVO4 HNSs exhibited excellent 2D structure as templates of BiOI nanoplates and well structure stability due to the in situ growth pattern of BiVO4 on BiOI. The 2D HNSs exhibited superior photocatalytic activities, especially the V/I8 2D HNSs (V:I = 80%), exhibited the highest Rhodamine B (RhB) and salicylic acid (SA) degradation rates, which are 29.8 times (RhB) and 15.7 times (SA) those of the individual BiVO4 and 6.4 times (RhB) and 10 times (SA) those of BiOI, respectively. Such excellent photocatalytic activities should be attributed to the organic combination of the 2D structure and heterojunction, as verified by the detailed morphology and composition characterizations. The well-known unique advantages of 2D nanost...

Hierarchically porous hexagonal microsheets constructed by well-interwoven MCo2S4 (M = Ni, Fe, Zn) nanotube networks via two-step anion-exchange for high-performance asymmetric supercapacitors

We report a significant advance in the design and fabrication of MCo2S4 (M = Ni, Fe, Zn) complex hierarchical structures with well-defined morphologies by achieving novel hierarchically porous hexagonal microsheets constructed by well-interwoven nanotube networks using a controllable two-step anion-exchange technique. Uniform and smooth hexagonal sheets are initially achieved for the first anion-exchange leading to nanowire-woven hexagons, followed by transformation of each nanowire to rough MCo2S4 nanotube via the second anion-exchange. The involved mechanism of this general top-down method allowing fine nanostructure control is clarified based on our proposed new insights into ion-induced anisotropic growth and time-dependent anion-exchange reaction kinetics. The merits of both maximized porosity and low resistance facilitate fast electron transfer/ion diffusion, thus NiCo2S4 electrode material exhibits a higher specific capacitance of 1780Fg−1 and superior rate capability than most reported NiCo2S4 nanostructures with different morphologies as well as excellent stability (92.4% capacity retention after 10,000 cycles at 10Ag−1). Furthermore, an asymmetric solid-state supercapacitor using such NiCo2S4 as positive and N-doped graphene film as negative electrodes achieves outstanding cycle ability (92.1% retention over 5000 cycles at 20Ag−1) and higher energy density of 67.2Whkg−1 (at 900Wkg−1) than that of similar devices. Such MCo2S4 electrode materials are promising for the future generation of high performance supercapacitors.

High-energy asymmetric supercapacitors based on free-standing hierarchical Co-Mo-S nanosheets with enhanced cycling stability.

Layered transition metal sulfides (TMS) are emerging as advanced materials for energy storage and conversion applications. In this work, we report a facile and cost-effective anion exchange technique to fabricate a layered, multifaceted, free standing, ultra-thin ternary cobalt molybdenum sulfide nanosheet (Co-Mo-S NS) architecture grown on a 3D porous Ni foam substrate. The unique Co-Mo layered double hydroxides are first synthesized as precursors and consequently transformed into ultra-thin Co-Mo-S NS. When employed as an electrode for supercapacitors, the Co-Mo-S NS delivered an ultra-high specific capacitance of 2343 F g-1 at a current density of 1 mA cm-2 with tremendous rate capability and extraordinary cycling performance (96.6% capacitance retention after 20 000 cycles). Furthermore, assembled Co-Mo-S/nitrogen doped graphene nanosheets (NGNS) in an asymmetric supercapacitor (ASC) device delivered an excellent energy density of 89.6 Wh kg-1, an amazing power density of 20.07 kW kg-1, and superior cycling performance (86.8% capacitance retention after 50 000 cycles). Such exceptional electrochemical performance of Co-Mo-S NS is ascribed to the good electrical contact with the 3D Ni foam, ultra-high contact area with the electrolyte, and enhanced architectural softening during the charging/discharging process. It is expected that the fabricated, unique, ultra-thin Co-Mo-S NS have great potential for future energy storage devices.

Hierarchical design of Cu1−xNixS nanosheets for high-performance asymmetric solid-state supercapacitors

A novel ultra-thin Cu1−xNixS nanosheet array supercapacitor electrode with high specific surface area, unique porosity and excellent conductivity was successfully developed via a powerful anion exchange technique.