Electrostatically Charged MoS2/Graphene Oxide Hybrid Composites for Excellent Electrochemical Energy Storage Devices

Carbon Dots Strongly Immobilized onto Carbon Nanohorns as Non-Metal Heterostructure with High Electrocatalytic Activity towards Protons Reduction in Hydrogen Evolution Reaction

Highly performing, non-metal inexpensive electrocatalysts for the production of hydrogen via electrochemical water splitting are called for the replacement of current platinum-based ones. In order to speed up the electrocatalytic hydrogen evolution, abundant active sites but also efficient charge transfer is needed. In this context, 0D carbon dots (CDs) with large specific surface area, low cost, high conductivity, and rich functional groups emerge as promising non-metal electrocatalysts. Additionally, the use of conductive substrates provides an effective strategy to boost their electrocatalytic performance. Herein, the unique 3D superstructure of carbon nanohorns (CNHs), as well as without any metal content in their structure, is used to provide a conductive support of high porosity, large specific surface area, and good electrical conductivity, for the in situ growth and immobilization of CDs, via a simple hydrothermal method. The direct contact of CDs with the 3D conductive network of CNHs promotes charge transfer, accelerating hydrogen evolution. The all-carbon non-metal CDs/CNHs nanoensembleshows an onset potential close to the one of Pt/C, low charge transfer resistance, and excellent stability.

A graphitic nano-onion/molybdenum disulfide nanosheet composite as a platform for HPV-associated cancer-detecting DNA biosensors

An electrochemical DNA sensor that can detect human papillomavirus (HPV)-16 and HPV-18 for the early diagnosis of cervical cancer was developed by using a graphitic nano-onion/molybdenum disulfide (MoS₂) nanosheet composite. The electrode surface for probing DNA chemisorption was prepared via chemical conjugation between acyl bonds on the surfaces of functionalized nanoonions and the amine groups on functionalized MoS₂ nanosheets. The cyclic voltammetry profile of an 1:1 nanoonion/MoS₂ nanosheet composite electrode had an improved rectangular shape compared to that of an MoS₂ nanosheet elecrode, thereby indicating the amorphous nature of the nano-onions with sp₂ distancing curved carbon layers that provide enhanced electronic conductivity, compared to MoS₂ nanosheet only. The nanoonion/MoS₂ sensor for the DNA detection of HPV-16 and HPV-18, respectively, was measured at high sensitivity through differential pulse voltammetry (DPV) in the presence of methylene blue (MB) as a redox indicator. The DPV current peak was lowered after probe DNA chemisorption and target DNA hybridization because the hybridized DNA induced less effective MB electrostatic intercalation due to it being double-stranded, resulting in a lower oxidation peak. The nanoonion/MoS₂ nanosheet composite electrodes attained higher current peaks than the MoS₂ nanosheet electrode, thereby indicating a greater change in the differential peak probably because the nanoonions enhanced conductive electron transfer. Notably, both of the target DNAs produced from HPV-18 and HPV-16 Siha and Hela cancer cell lines were effectively detected with high specificity. The conductivity of MoS₂ improved by complexation with nano-onions provides a suitable platform for electrochemical biosensors for the early diagnosis of many ailments in humans.

Doping molybdenum oxides with different non-metal atoms to promote bioelectrocatalysis in microbial fuel cells

The sluggish extracellular electron transfer has been known as one of the bottlenecks to limit the power density of microbial fuel cells (MFCs). Herein, molybdenum oxides (MoO_x) are doped with various types of non-metal atoms (N, P, and S) by electrostatic adsorption, followed by high-temperature carbonization. The as-prepared material is further used as MFC anode. Results indicate that all different elements-doped anodes can accelerate the electron transfer rate, and the great enhancement mechanism is attributed to synergistic effect of dopped non-metal atoms and the unique MoO_x nanostructure, which offers high proximity and a large reaction surface area to promote microbe colonization. This not only enables efficient direct electron transfer but also enriches the flavin-like mediators for fast extracellular electron transfer. This work renders new insights into doping non-metal atoms onto metal oxides toward the enhancement of electrode kinetics at the anode of MFC.

Optimized Pinecone-Squama-Structure MoS2-Coated CNT and Graphene Framework as Binder-Free Anode for Li-Ion Battery with High Capacity and Cycling Stability

Extensive research has been conducted on the development of high-rate and cyclic stability anodes for lithium batteries (LIBs) due to their high energy density. Molybdenum disulfide (MoS₂) with layered structure has garnered significant interest due to its exceptional theoretic Li⁺ storage behavior as anodes (670 mA h g^-1). However, achieving a high rate and long cyclic life of anode materials remains a challenge. Herein, we designed and synthesized a free-standing carbon nanotubes-graphene (CGF) foam, then presented a facile strategy to fabricate the MoS₂-coated CGF self-assembly anodes with different MoS₂ distributions. Such binder-free electrode possesses the advantages of both MoS₂ and graphene-based materials. Through rational regulation of the ratio of MoS₂, the MoS₂-coated CGF with uniformly distributed MoS₂ exhibits a nano pinecone-squama-like structure that can accommodate the large volume change during the cycle process, thereby significantly enhancing the cycling stability (417 mA h g^-1 after 1000 cycles), ideal rate performance, and high pseudocapacitive behavior (with a 76.6% contribution at 1 mV s^-1). Such a neat nano-pinecone structure can effectively coordinate MoS₂ and carbon framework, providing valuable insights for the construction of advanced anode materials.

Improving the Performance of the Lamellar Reduced Graphene Oxide/Molybdenum Sulfide Nanofiltration Membrane through Accelerated Water-Transport Channels and Capacitively Enhanced Charge Density

Graphene is promising in the construction of next-generation nanofiltration membranes for wastewater treatment and water purification. However, the application of graphene-based membranes has still been prohibited by their deficiencies in permeability and ion rejection. Herein, regulating the 2D channel and enhancing the charge density are co-adopted for simultaneous enhancement of the water flux and salt rejection of reduced graphene oxide (rGO) membranes through the intercalation of molybdenum sulfide (MoS₂) nanosheets and external electrical assistance. The fabricated rGO/MoS₂ membranes possess expanded nanochannels with less friction and a higher water molecule transport velocity gradient (from 8.57 to 14.07 s^-1) than those of rGO membranes. Consequently, their water permeance increases from 0.92 to 34.9 L m^-2 h^-1 bar^-1. Meanwhile, benefiting from the high capacitance and negative potential of -1.1 V versus the saturated calomel electrode given to the membranes, their rejection rates toward NaCl reach 87.2% and those toward Na₂SO₄ reach 93.7%. The Donnan steric pore model analysis indicates that the capacitively and electrically increased surface charge density make great contributions to the higher ion rejection rate. This work gives new insights into membrane design for high water flux and salt rejection efficiency.

Coal-Derived Graphene/MoS2 Heterostructure Electrodes for Li-Ion Batteries: Experiment and Simulation Study

A novel coal-derived graphene-intercalated MoS₂ heterostructure was prepared with a facile in situ hydrothermal approach followed by high-temperature calcination. XRD, FE-SEM, HR-TEM, HR-Raman, and TOC analytical instruments, combined with first-principles simulations, were employed to explore the structural and electrochemical properties of this heterostructure for use as an electrode material. The XRD measurements and simulations confirmed the formation of the MoS₂/graphene (MoS₂-G) heterostructure. The microstructure analysis indicated that a well-defined 3D flower-like structure with tunable interlayer distances was created in the MoS₂ layer. The novel MoS₂-09% G anode exhibits a remarkable initial discharge capacity of ∼929 mAh/g due to its interlayer expansion from the intercalation of graphene between the MoS₂ layers. This anode maintains a capacity of ∼813 mAh/g with a Coulombic efficiency (CE) of ∼99% after 150 cycles at a constant current density of 100 mA/g. This anode also delivers a high-rate capability of ∼579 mAh/g at a current density of 2000 mA/g, significantly higher than that of other comparable structures. The unique flower-like arrangement, sufficient interlayer spacing for Li-ion diffusion, and the increased conductive matrix created using coal-derived graphene enhance the electrode kinetics during electrochemical reactions. Our first-principles calculations revealed that the diffusion barriers are significantly lower in heterostructures compared to that of bare MoS₂. This heterostructure design has significant potential as a new type of anode for Li-ion storage in next-generation batteries.

Insights into the Influence of Key Preparation Parameters on the Performance of MoS2/Graphene Oxide Composites as Active Materials in Supercapacitors

Advances in energy storage and energy conversion play an essential role nowadays because the energy demands are becoming greater than ever. To overcome the actual performances of the materials used to build supercapacitors, a combination of transition metal dichalcogenides (TMDCs) and graphene oxide (GO) or reduced graphene oxide (rGO) as graphene-based structures are often studied for their excellent properties, such as high specific area and good electrical conductivity. Nevertheless, synthesis pathways and parameters play key roles in obtaining better materials as components for supercapacitors with higher technical performances. Driven by the desire to understand the influence of the structural and morphological particularities on the performances of supercapacitors based on MoS2/graphene oxide (GO) composites, a survey of the literature was performed by pointing out the alterations induced by different synthesis pathways and key parameters to the above-mentioned particularities.

A 2H-MoS2/carbon cloth composite for high-performance all-solid-state supercapacitors derived from a molybdenum dithiocarbamate complex

A molecular complex Mo₂O₂(μ-S)₂(Et₂dtc)₂ (dtc = dithiocarbamate) is prepared and loaded onto carbon cloth (CC) through facile solvothermal treatment, followed by subsequent single-source pyrolysis. This results in a highly porous 2H-MoS₂/CC composite with a sponge-like stacked lamellar morphology. Due to its high porosity and unique nano/microstructure, the MoS₂/CC composite exhibits a specific capacitance of 550.0 F g^-1 at 1 A g^-1, outperforming some 1T-MoS₂ based electrodes. The composite is further assembled into a symmetric all-solid-state supercapacitor, which can be operated stably at a wide potential window and shows a specific capacitance of 127.5 F g^-1 at 1 A g^-1. In addition, the device delivers a high energy density of 70.8 W h kg^-1 at 1 kW kg^-1, which still remains 15.0 W h kg^-1 at 18.0 kW kg^-1. 75% of the performance of the device can be retained after 8000 cycles. Such remarkable electrochemical performance is attributed to its novel nano/microstructures with a large surface area, convenient ion transport pathways, enhanced conductivity, and improved structural stability. Thus, this work demonstrates a highly promising dithiocarbamate-based single-precursor pyrolysis route towards the fabrication of metal sulfides/carbon composites for energy storage applications.

In-situsputtered 2D-MoS2nanoworms reinforced with molybdenum nitride towards enhanced Na-ion based supercapacitive electrodes

We report the fabrication of binder-free, low-cost and efficient hybrid supercapacitive electrode based on the hexagonal phase of two-dimensional MoS₂nanoworms reinforced with molybdenum nitride nanoflakes deposited on stainless steel (SS) substrate using reactive magnetron sputtering technique. The hybrid nanostructured MoS₂-Mo₂N/SS thin film working electrode delivers a high gravimetric capacitance (351.62 F g^-1at 0.25 mA cm^-2) investigated in 1 M Na₂SO₄aqueous solution. The physisorption/intercalation of sodium (Na⁺) ions in electroactive sites of MoS₂-Mo₂N composite ensures remarkable electrochemical performance. The deposited porous nanostructure with good electrical conductivity and better adhesion with the current collector demonstrates a high-energy density of 82.53 Wh kg^-1in addition to a high-power density of 24.98 kW kg^-1. Further, excellent capacitance retention of 93.62% after 4000 galvanostatic charge-discharge cycles elucidated it as a promising candidate for realizing high-performance supercapacitor applications.

Recent Advances in Two-Dimensional Quantum Dots and Their Applications

Two-dimensional quantum dots have received a lot of attention in recent years due to their fascinating properties and widespread applications in sensors, batteries, white light-emitting diodes, photodetectors, phototransistors, etc. Atomically thin two-dimensional quantum dots derived from graphene, layered transition metal dichalcogenide, and phosphorene have sparked researchers' interest with their unique optical and electronic properties, such as a tunable energy bandgap, efficient electronic transport, and semiconducting characteristics. In this review, we provide in-depth analysis of the characteristics of two-dimensional quantum dots materials, their synthesis methods, and opportunities and challenges for novel device applications. This analysis will serve as a tipping point for learning about the recent breakthroughs in two-dimensional quantum dots and motivate more scientists and engineers to grasp two-dimensional quantum dots materials by incorporating them into a variety of electrical and optical fields.

Advanced materials and technologies for supercapacitors used in energy conversion and storage: a review

Supercapacitors are increasingly used for energy conversion and storage systems in sustainable nanotechnologies. Graphite is a conventional electrode utilized in Li-ion-based batteries, yet its specific capacitance of 372 mA h g−1 is not adequate for supercapacitor applications. Interest in supercapacitors is due to their high-energy capacity, storage for a shorter period and longer lifetime. This review compares the following materials used to fabricate supercapacitors: spinel ferrites, e.g., MFe2O4, MMoO4 and MCo2O4 where M denotes a transition metal ion; perovskite oxides; transition metals sulfides; carbon materials; and conducting polymers. The application window of perovskite can be controlled by cations in sublattice sites. Cations increase the specific capacitance because cations possess large orbital valence electrons which grow the oxygen vacancies. Electrodes made of transition metal sulfides, e.g., ZnCo2S4, display a high specific capacitance of 1269 F g−1, which is four times higher than those of transition metals oxides, e.g., Zn–Co ferrite, of 296 F g−1. This is explained by the low charge-transfer resistance and the high ion diffusion rate of transition metals sulfides. Composites made of magnetic oxides or transition metal sulfides with conducting polymers or carbon materials have the highest capacitance activity and cyclic stability. This is attributed to oxygen and sulfur active sites which foster electrolyte penetration during cycling, and, in turn, create new active sites.

Building Hierarchical Microcubes Composed of One-Dimensional CoSe2 @Nitrogen-Doped Carbon for Superior Sodium Ion Batteries

Designing and synthesizing highly stable anode materials with high capacity is critical for the practical application of sodium ion batteries (SIBs), however, to date, this remains an insurmountable barrier. The introduction of hierarchical architectures and carbon supports is proving an effective strategy for addressing these challenges. Thus, we have fabricated a hierarchical CoSe₂ @nitrogen-doped carbon (CoSe₂ @NC) microcube composite using the Prussian blue analogue Co₃ [Co(CN)₆ ]₂ as template. The rational combination of the unique hierarchical construction from one to three dimensions and a nitrogen-doped carbon skeleton facilitates sodium ion and electron transport as well as stabilizing the host structure during repeated discharge/charge processes, which contributes to its excellent sodium storage capability. As expected, the as-prepared CoSe₂ @NC composite delivered remarkable reversible capacity and ultralong cycling lifespan even at a high rate of 2.0 A g^-1 (384.3 mA h g^-1 after1800 loops) when serving as the anode material for SIBs. This work shows the great potential of the CoSe₂ -based anode for practical application in SIBs, and the original strategy may be extended to other anode materials.

Inkjet-Printed Ultrathin MoS2-Based Electrodes for Flexible In-Plane Microsupercapacitors

Flexible and wearable energy storage microdevice systems with high performance and safety are promising candidates for the electronics of on-chip integration. Herein, we demonstrate inkjet-printed ultrathin electrodes based on molybdenum disulfide (MoS₂) nanosheets for flexible and all-solid-state in-plane microsupercapacitors (MSCs) with high capacitance. The MoS₂ nanosheets were uniformly dispersed in the low-boiling point and nontoxic solvent isopropanol to form highly concentrated inks suitable for inkjet printing. The MSCs were assembled by printing the highly concentrated MoS₂ inks on a polyimide substrate with appropriate surface tension using a simple and low-cost desktop inkjet printer. Because of the two-dimensional structure of MoS₂ nanosheets, the as-assembled planar MSCs have high loadings of active materials per unit area, resulting in more flexibility and thinness than the capacitors with a traditional sandwich structure. These planar MSCs can not only possess any collapsible shape through the computer design but also exhibit excellent electrochemical performance (with a maximum energy density of 0.215 mW h cm^-3 and a high-power energy density of 0.079 W cm^-3), outstanding mechanical flexibility (almost no degradation of capacitance at different bending radii), good cycle stability (85.6% capacitance retention even after 10,000 charge-discharge cycles), and easy scale-up. Moreover, a blue light-emitting diode can be powered using five MSCs connected in series. The in-plane and low-cost MSCs with high energy densities have great application potential for integrated energy storage systems including wearable planar solar cells and other electronics.

Boosting the performance of cobalt molybdate nanorods by introducing nanoflake-like cobalt boride to form a heterostructure for aqueous hybrid supercapacitors

Binary transition metal oxides have received extensive attention because of their multiple oxidation states. However, due to the inherent vices of poor electronic/ionic conductivities, their practical performance as supercapacitor material is limited. Herein, a cobalt molybdate/cobalt boride (CoMoO₄/Co-B) composite is constructed with cobalt boride nanoflake-like as a conductive additive in CoMoO₄ nanorods using a facile water bath deposition process and liquid-phase reduction method. The effects of CoMoO₄/Co-B mass ratios on its electrochemical performance are investigated. Remarkably, the CoMoO₄/Co-B composite obtained at a mass ratio of 2:1 shows highly enhanced electrochemical performance relative to those obtained at other ratios and exhibits an optimum specific capacity of 436 F g^-1 at 0.5 A g^-1. This kind of composite could also display great rate capacity (294 F g^-1 at 10 A g^-1) and outstanding long cycle performance (90.5% capacitance retention over 10 000 cycles at 5 A g^-1). Also, the asymmetric supercapacitor device is prepared by using CoMoO₄/Co-B composite as the anode with the active carbon as the cathode. Such a device demonstrates an outstanding energy density of 23.18 Wh kg^-1 and superior long-term stability with 100% initial specific capacity retained after 10,000 cycles. The superior electrochemical properties show that the CoMoO₄/Co-B electrode material has tremendous potential in energy storage equipment applications.

CuO nanorods grown vertically on graphene nanosheets as a battery-type material for high-performance supercapacitor electrodes

This work reports the preparation and characterization of the CuO nanorods grown vertically on graphene nanosheets, denoted as CuO/rGO@NF. Graphene is deposited by electrostatic attraction showing the morphology of folded nanosheets, which improves the electrical conductivity of the electrode, while CuO is modified by filtered cathodic vacuum arc technology and subsequent electrochemical oxidation presenting the morphology of nanorods, which increases the contact area of active sites and shortens the ion and electronic diffusion path. The results show that the CuO/rGO@NF electrode deliver an ultrahigh specific capacity (2.51 C cm⁻² at 2 mA cm⁻²), remarkable rate performance (64.6%) and improved conductivity. A symmetrical supercapacitor is assembled by two identical electrodes, presenting the maximum energy density of 38.35 W h kg⁻¹ at a power density of 187.5 W kg⁻¹. Therefore, the CuO/rGO@NF electrode can be used as a prospective electrode for energy storage devices. In addition, the whole electrode preparation process is short in time, safe and environmentally friendly, which provides a new idea for the preparation of other electrode materials.

The CuO/rGO@NF electrode is prepared by a simple and time-saving method, which has ultrahigh area capacity and excellent rate performance.

Hydrogen Bond between Molybdate and Glucose for the Formation of Carbon-Loaded MoS2 Nanocomposites with High Electrochemical Performance

The effects of glucose on the growth and surface properties of MoS₂ with a nanosheet structure were investigated in detail. In the presence of glucose, the hydrothermal reaction of sodium molybdate and thiourea yields carbon-loaded MoS₂ nanocomposites (C/MoS₂). Compared with bare MoS₂ nanosheets with more than six layers obtained in the absence of glucose and carbon spheres with a diameter of 500 nm prepared from the carbonization of glucose, C/MoS₂ consists of one- or three-layered MoS₂ and carbon spheres with a diameter less than 1 nm to give a large Brunauer-Emmett-Teller surface area (3-20 times larger than the individual materials). The surface characterizations reveal that both MoS₂ and carbon spheres of C/MoS₂ have a negative charge on the surface, suggesting that the previously reported explanation, in which the adsorption of MoS₂ and/or molybdate ions on carbon spheres inhibits the growth and aggregation of MoS₂, is not correct. Based on Fourier transform infrared and ¹H NMR spectra, it is demonstrated that glucose acts as the hydrogen bond donor toward polyoxomolybdate species such as Mo₈O₂₆^4-, Mo₇O₂₄^6-, and MoO₄^2- in the range of pH = 2-12. The intermolecular hydrogen bond not only inhibits the growth of both the (002) plane of MoS₂ and carbon spheres, but also enables the formation of C-O-Mo bonds in the in situ generated C/MoS₂. Compared with bare MoS₂, C/MoS₂ not only show a lower over-potential by 60 mV for the electrocatalytic evolution of hydrogen, but also has a larger mass specific capacitance by three times, due to the larger surface area and the interfacial interaction through the C-O-Mo bonds.

Experimental and Theoretical Investigation of the Effect of Oxygen Vacancies on the Electronic Structure and Pseudocapacitance of MnO2

Defect engineering is an effective way to modulate the intrinsic physicochemical properties of materials. In this work, δ-MnO₂ with oxygen vacancies is fabricated by a simple oxidation or reduction process, and the relationship between the electronic structure and pseudocapacitance is systematically studied through experimental analysis and theoretical calculations. The peaks in the Raman spectra of the as-prepared samples are shifted compared with those of pure MnO₂ and the Mn³⁺ /Mn⁴⁺ ratio and O species content also change after the introduction of oxygen vacancies. The optimized samples exhibit a better specific capacitance of 207 F g^-1 after the oxidation process and 181.4 F g^-1 after the reduction treatment compared with only 143.9 F g^-1 for the pure MnO₂ . The samples obtained through the oxidation or reduction process also retain 93.3 or 86.4 % of the initial capacity after 5000 cycles. The excellent properties are attributed to the enhanced conductivity and increased surface reactivity or electrochemically active sites. Theoretical calculations demonstrate that the presence of oxygen vacancies leads to an increase in the density of states, which improves the redox reaction of MnO₂ . This study will provide a reference for exploring and designing highperformance pseudocapacitive materials.

Electronic Properties of Armchair Black Phosphorene Nanoribbons Edge-Modified by Transition Elements V, Cr, and Mn

The structural, electrical, and magnetic properties of armchair black phosphorene nanoribbons (APNRs) edge-functionalized by transitional metal (TM) elements V, Cr, and Mn were studied by the density functional theory combined with the non-equilibrium Green's function. Spin-polarized edge states introduce great varieties to the electronic structures of TM-APNRs. For APNRs with Mn-stitched edge, their band structures exhibit half-semiconductor electrical properties in the ferromagnetic state. A transverse electric field can then make the Mn-APNRs metallic by shifting the conduction bands of edge states via the Stark effect. The Mn/Cr-APNR heterojunction may be used to fabricate spin p-n diode where strong rectification acts only on one spin.

Synthesis of Large-Area Single-Layer Graphene Using Refined Cooking Palm Oil on Copper Substrate by Spray Injector-Assisted CVD

We present a synthesis of large-area single-layer graphene on copper substrate using a refined cooking palm oil, a natural single carbon source, by a home-made spray injector-assisted chemical vapor deposition system. The effects of the distance between spray nozzle and substrate, and growth temperature are studied. From Raman mapping analysis, shorter distance of 1 cm and temperature of around 950 °C lead to the growth of large-area single-layer graphene with a coverage up to 97% of the measured area size of 6400 μm². The crystallinity of the grown single layer graphene is relatively good due to high distribution percentage of FWHM values of 2D band that is below 30 cm^-1. However, the defect concentration is relatively high, and it suggests that a flash-cooling technique needs to be introduced.

Using Different Ions to Tune Graphene Stack Structures from Sheet- to Onion-Like During Plasma Exfoliation, with Supercapacitor Applications

In this article, we report a facile and simple approach for tuning graphene nanosheet structures (GNS) with different ions in the electrolytes through cathodic plasma exfoliation process in electrochemical reactions. We obtained sheet- and onion-like GNS when aqueous electrolyte NaOH and H₂SO₄, respectively, were present during plasma exfoliation in the electrochemical reactions, as evidenced from scanning electron microscopy and transmission electron microscopy images. Moreover, the onion-like GNS exhibited a specific surface area of 464 m² g^-1 and a supercapacitive performance of 67.1 F g^-1, measured at a scan rate of 5 mV s^-1 in 1 M NaCl; these values were much higher than those (72 m² g^-1 and 21.6 F g^-1, respectively) of the sheet-like GNS. This new approach for efficiently generating tunable stacked graphene structures with different ions, in the cathodic plasma exfoliation process, has promising potentials for use in energy storage devices.

ZIF-67 derived Co3O4/carbon aerogel composite for supercapacitor electrodes

We report carbon aerogels with a 3D hierarchical porous structure as a backbone to support nanoporous Co₃O₄ derived from ZIF-67 for supercapacitors.

Liquid phase reduction synthesis of a cobalt boride–activated carbon composite with improved specific capacitance and retention rate as a new positive electrode material for supercapacitors

Amorphous cobalt boride–activated carbon was synthesized via a one-step liquid phase reduction method and its electrochemical performance was studied.

Bifunctional iron disulfide nanoellipsoids for high energy density supercapacitor and electrocatalytic oxygen evolution applications

FeS₂, prepared using a rapid microwave assisted method, exhibits excellent electrochemical performance for supercapacitor and OER applications.