Covalent Connection Research Articles

Enhanced Oral Delivery of Curcumin via Vitamin E TPGS Modified Nanodiamonds: a Comparative Study on the Efficacy of Non-covalent and Covalent Conjugated Strategies.

Despite that either non-covalent or covalent attachment of hydrophilic polymers or surfactants onto nanodiamonds (NDs) could overcome the shortcomings of being a drug delivery system, it is hard to draw a definite conclusion which strategy is more effective. Hence, with the purpose of comparing the influence of different coating approach of NDs on the oral delivery efficiency of water-insoluble model drug curcumin (CUR), NDs were firstly modified with D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) via non-covalent or covalent conjugation method, and then loaded with CUR (CUR@NDs-COOH/TPGS or CUR@NDs-TPGS). In comparison with the core-shell-structured CUR@NDs-COOH/TPGS, CUR@NDs-TPGS were irregular in shape with dense TPGS film, and exhibited smaller size, more negatively potential, and higher drug loading efficiency. The covalent connection group also showed higher anti-cancer activity, cellular uptake, and permeability through the Caco-2 cell monolayers, as well as favorable distribution, penetration, and retention in rat intestines. The oral bioavailability study in rats demonstrated that CUR@NDs-TPGS showed significantly greater Cmax and AUC0-t in contrast with CUR suspension and the TPGS-coated ones, respectively. The findings illustrated that covalent grafting TPGS onto the surface of NDs possesses better efficacy and biocompatibility on oral delivery of poorly soluble drug CUR than pristine and non-covalent coated nanoparticles.

Aromatic interactions with membrane modulate human BK channel activation.

Large-conductance potassium (BK) channels are transmembrane (TM) proteins that can be synergistically and independently activated by membrane voltage and intracellular Ca2+. The only covalent connection between the cytosolic Ca2+ sensing domain and the TM pore and voltage sensing domains is a 15-residue 'C-linker'. To determine the linker's role in human BK activation, we designed a series of linker sequence scrambling mutants to suppress potential complex interplay of specific interactions with the rest of the protein. The results revealed a surprising sensitivity of BK activation to the linker sequence. Combining atomistic simulations and further mutagenesis experiments, we demonstrated that nonspecific interactions of the linker with membrane alone could directly modulate BK activation. The C-linker thus plays more direct roles in mediating allosteric coupling between BK domains than previously assumed. Our results suggest that covalent linkers could directly modulate TM protein function and should be considered an integral component of the sensing apparatus.

Alendronate loaded graphene oxide functionalized collagen sponge for the dual effects of osteogenesis and anti-osteoclastogenesis in osteoporotic rats

Graphene Oxide (GO)-related hydrogels have been extensively studied in hard tissue repair, because GO can not only enhance the mechanical properties of polymers but also promote osteogenic differentiation of mesenchymal stem cells. However, simple GO-related hydrogels are not ideal for the repair of osteoporotic bone defects as the overactive osteoclasts in osteoporosis. Alendronate (Aln) is known to inhibit osteoclasts and may bind to GO through covalent connection. Therefore, delivering Aln in GO-related hydrogels may be effective to repair osteoporotic bone defects. Here, we developed a control-released system which is constructed by collagen (Col)-GO sponges loaded with Aln (Col-GO-Aln) for osteoporotic bone defect repair. In vitro, Col-GO-Aln sponges prolonged the release period of Aln, and the sponge containing 0.05% (w/v) GO released Aln faster than sponge with 0.2% GO. Furthermore, tartrate-resistant acid phosphatase (TRAP) and F-actin staining demonstrated that Col-GO-Aln sponges effectively inhibited osteoclastogenesis of monocyte-macrophages. In vivo, micro-CT scan showed that the volume of newborn bone in defect site by 0.05% GO sponge was nearly three times larger than that of other groups. Moreover, the CT and histological examinations of rat femur proved that Col-GO-Aln sponges decreased the number of osteoclasts and suppressed the systemic bone loss in osteoporotic rats. These findings reveal that the application of GO as carriers of anti-osteoporosis drugs is a viable treatment for osteoporosis. The results also underscore the potential of GO-related hydrogels with Aln-releasing capacity for bone regeneration in osteoporosis.

Solid-state photochromism and acidochromism multifunctional materials constructed by tetraphenylethene and spiropyran

Solid-state stimuli-responsive materials are attracting increasing attention due to their broad prospects in the field of functional materials, but there are still some challenges. We design and synthesize two efficient solid-state stimuli-responsive materials SP-TPEm (m = 4, 6) based on TPE covalent connection with N-position of spiropyran through different lengths of alkyl spacers. Both of them show aggregation-induced emission behaviors. Efficient solid-state photoswitching between SP-TPEm and their photoisomer MC-TPEm is achieved. Both of the two films show great stimulus-responsive properties, and the characteristic emission peak is at around 460 nm for TPE and 601 nm for MC isomer. Therefore, SP-TPE4 is applied as an anticounterfeiting ink due to its great solid-state photochromic characteristics. In addition, the solid-state films of SP-TPEm are acidochromic responsive. Moreover, the surface wettability of the SP-TPEm films can be adjusted by UV light. Hence, we provide a new strategy for building solid-state multifunctional materials.

Donor–acceptor conjugates-functionalized aluminum phthalocyanines: Photophysical and nonlinear optical properties

Photoinduced electron transfer/energy transfer (PET/ET) plays a very important role in improving the nonlinear optical (NLO) response. AlPc-Aqn and HAlPc-Aqn with donor-acceptor (D-A) structure were prepared by grafting aluminum phthalocyanine (AlPc) and hyperbranched aluminum phthalocyanine (HAlPc) through anthraquinone axial covalent bonding. After the axial covalent connection, the formed D-A phthalocyanine materials enhance the PET/ET process between the phthalocyanine ring and the anthraquinone structure, which results in significant fluorescence quenching and effectively improves the material's NLO properties. The discrepancy of LUMO levels (ΔE) further confirms that both AlPc-Aqn and HAlPc-Aqn formed a D-A system. This effectively promotes the electron transfer between the anthraquinone and the phthalocyanine ring, performing enhanced NLO response. Furthermore, compared to AlPc-Aqn, the special three-dimensional structure of HAlPc-Aqn brings a more efficient PET/ET process and exhibits a larger nonlinear absorption coefficient.

Nanohybrid material based on carbazole-thiophene-functionalized MWCNT and grafted poly(3-hexylthiophene): Preparation, characterization and spectroelectrochemistry

This work reports the preparation of two novel materials: a non-covalently bonded hybrid based on amino-carbazole-functionalized multi-walled carbon nanotube (MWCNTCO-NHCbz) and poly(3-dodecylthiophene) (P3DDT) and a covalently bonded nanohybrid based on MWCNT functionalized with 3,6-diamino-methylcarbazole (H2NCbzNH2), 3-carboxythiophene (ThCOOH) and a final grafting of poly(3-hexylthiophene) (P3HT). These materials were characterized by several spectroscopic techniques that proved their successfully preparation. Beyond the thermal, electrochemical, electrical and morphological characterizations, thin films of both materials were also tested by spectroelectrochemical experiments. The covalently bonded material presented a better electrochromic performance when compared with the other material: optical contrast three times higher (6%); coloration efficiency of 10.8 C−1 cm2; fast response times on the scale of few seconds; and greater long-term cyclability presenting a stable color changing memory and 73% of the original charge after 100 cycles. This enhanced performance might be related to the benefits provided by the covalent connections between the building blocks, such an important strategy of tailoring hybrid materials for multifunctional applications.

Insight into a Eu2+-activated zirconium-silicate yellow phosphor for multifunctional applications

To better meet the needs of modern science and technology for new inorganic functional materials, the exploration of new Eu2+-doped phosphors is of great significance. In this work, a zirconium-silicate yellow phosphor, K2ZrSiO5:Eu2+, was explored through theoretical calculations and systematic experiments for use in multifunctional applications. The crystal structure, electronic structure, photoluminescence (PL) and cathodoluminescence (CL) properties of K2ZrSiO5:Eu2+ were investigated in detail. As a result, owing to the open framework and the lattice with the covalent connection, K2ZrSiO5:Eu2+ phosphor exhibits strong yellow light emission under the near-ultraviolet and electron beam excitation. However, the K2ZrSiO5:Eu2+ phosphor suffers a poor thermal stability. Furthermore, the K2ZrSiO5:Eu2+ phosphor exhibits good anti-saturation and anti-aging characteristics under the electron beam excitation. The results indicate that the development of K2ZrSiO5:Eu2+ phosphor can provide a new insight into discovering multifunctional materials.

The Use of Electroactive Ureidopyrimidones As Redox-Responsive Chain Terminators for Supramolecular Polymers

Unlike conventional polymers, in which monomers are reacted to form strong covalent connections, supramolecular polymers are formed by linking together monomers via weaker, non-covalent interactions such as H-bonds, ion-dipole interactions and so on. One very well-studied class of supramolecular polymers are based on the ureidopyrimidones, UPy’s, which dimerize via 4 strong, linear H-bonds in non-competitive solvents. Monomers for supramolecular polymerization can be made by linking together 2 or more UPy units with short covalent chains. Under dimerization conditions, the UPy’s link up to form longer polymeric chains. One of the useful attributes of such polymers is their self-healing ability. Application of heat or mechanical stress will readily break the monomers apart at the H-bonds, but, upon cooling or relief of stress, the bonds reform. The goal of this research is to see if electron transfer can be used as an alternative, more selective stimulus to break apart the UPy chains. As a first step in this direction, the use of our previously studied electroactive UPy’s, 1a and 1b, are being investigated as redox-active chain terminators. For these studies the known UPy monomer, 2, was synthesized. Viscosity measurements of solutions of 2 in 0.1 M NBu4PF6/CH2Cl2 give a critical polymerization concentration of 20 mM. Based on this, 60 mM 2 was chosen as the working concentration for initial experiments giving a solution with a specific viscosity of 3.0 mPa∙s. Upon addition of 2 mM of the ferrocene containing UPy 1a, the viscosity dropped to 1.1 mPa∙s, indicating that 1a is an effective chain terminator, decreasing the lengths of the chains which results in a decrease in the viscosity of the solution The ferrocenes were then completely oxidized to the ferrocenium form in a two compartment electrochemical cell. This caused the viscosity of the solution to increase from 1.0 to 1.7 mPa∙s, suggesting decreased effectiveness of the ferrocenium form as a chain terminator. This is consistent with poorer binding of the ferrocenium form to the bis-UPy. Importantly, reduction back to the ferrocene led to a decrease in the viscosity back to close to where it was initially. In this presentation, the results of further studies on the ability of both 1a and 1b to act as redox-responsive chain terminators for UPy-based supramolecular polymers will be reported. Figure 1

Enhanced thermal conductivity of natural rubber based thermal interfacial materials by constructing covalent bonds and three-dimensional networks

With the rapid development of electronic integration technology, the timely and efficient heat dissipation capacity has become increasingly important to ensure reliability and lifetime of electronics. Thermal interface materials (TIMs) were considered as the best candidate to tackle this issue. In this work, the three-dimensional structures with covalent bond connections of boron nitride/natural rubber (BN/NR) thermal interface composites were successfully prepared and its possessed an ameliorated through-plane thermal conductivity of 0.79 W m−1 K−1 when BN content were 25 wt%. The results demonstrated that three-dimensional network structures and chemical interactions between BN and NR had a significant contribution in reducing interfacial thermal resistance. Meanwhile, the sensitive thermal response, satisfactory electrical insulation and good mechanical properties made its own high probability for the TIMs applications. Importantly, this tactics created a new means to construct elastomer-based thermal management materials and applied for the electronic packing materials.

Photocross-linking Kinetics Study of Benzophenone Containing Zwitterionic Copolymers.

The kinetics of benzophenone (BP) and its derivatives have been widely studied in different solvents by nanosecond laser flash photolysis as well as in the polymer matrix. With the development of functional polymer coating, BP, as well as other photocross-linkers, has been incorporated into the polymer backbone or side chain to form the covalent connection between polymer coatings and substrates, which can improve the mechanical and chemical stability of the coatings. In this work, a series of BP pendent zwitterionic copolymer kinetics were investigated using UV–vis for the first time. Because of the high hydrophilicity of the zwitterionic monomer, the influence of the polymer matrix’s polarity on the cross-linking rate was observed. With a higher zwitterionic percentage in the copolymer, the polarity of the copolymer increases, BP reactivity decreases, and a hypothesis between the BP rate constant and partial coefficient log P was raised. Moreover, the thermal property is also an important factor affecting the BP reactivity. For polymers with high glass-transition temperature, the reactivity was not dominated by the chemical environment such as polarity, and the restricted segment movement reduces the cross-linking rate. Additionally, the ring substituents show similar effects to BP pendent copolymers as with small molecules. Electron-withdrawing groups help to stabilize the BP triplet radical and facilitate cross-linking, while electron-donating groups work conversely. Therefore, polarity, thermal properties, and substituents should be taken into consideration when designing BP-containing functional polymers.

Core-Shell Structured Phenolic Polymer@TiO2 Nanosphere with Enhanced Visible-Light Photocatalytic Efficiency.

Core–shell structured TiO2 is a promising solution to promote the photocatalytic effectiveness in visible light. Compared to metal or semiconductor materials, polymers are rarely used as the core materials for fabricating core–shell TiO2 materials. A novel core–shell structured polymer@TiO2 was developed by using phenolic polymer (PP) colloid nanoparticles as the core material. The PP nanoparticles were synthesized by an enzyme-catalyzed polymerization in water. A subsequent sol–gel and hydrothermal reaction was utilized to cover the TiO2 shell on the surfaces of PP particles. The thickness of the TiO2 shell was controlled by the amount of TiO2 precursor. The covalent connection between PP and TiO2 was established after the hydrothermal reaction. The core–shell structure allowed the absorption spectra of PP@TiO2 to extend to the visible-light region. Under visible-light irradiation, the core–shell nanosphere displayed enhanced photocatalytic efficiency for rhodamine B degradation and good recycle stability. The interfacial C–O–Ti bonds and the π-conjugated structures in the PP@TiO2 nanosphere played a key role in the quick transfer of the excited electrons between PP and TiO2, which greatly improved the photocatalytic efficiency in visible light.

Characteristics of glucose oxidase immobilized on Magnetic Chitosan Nanoparticles

Abstract Immobilization process is used to facilitate the enzyme recovery and reusability. The aims of this study were to evaluate the effect of different amounts of chitosan on immobilization efficiency of Glucose Oxidase (GOX), pH effect on enzyme activity and changes of kinetic characteristics of enzyme immobilized on Magnetic Chitosan Nanoparticles (MCNP). GOX was immobilized on MCNP with cross bonds and Schiff base covalent connections. The sample with 0.3 g of chitosan had the highest immobilization efficiency (41.30%). Morphology of nanoparticles was investigated by Scanning Electron Microscopy (SEM). Immobilization of GOX on magnetic nanoparticles was verified with Fourier Transform Infrared (FTIR). The effect of pH on enzyme activity was similar on both immobilized enzyme (IE) and free enzyme (FE). The evaluation of kinetic parameters for IE and FE has showed that the effectiveness factor was 0.45. Generally, it could be concluded that magnetic nanoparticles with 0.3 g chitosan could provide a suitable medium for immobilization of GOX.

Structure, function and applications of phycoerythrin: a unique light harvesting protein in algae

<p indent="0mm">Photosynthesis is an ancient and important chemical reaction process. Under light conditions, plants, algae, and certain bacteria convert solar energy into chemical energy. And then, chemical energy is directly used by living cells. A special light-harvesting pigment protein, phycobiliprotein (PBP), exists in red algae, cyanobacteria (blue-green algae), and some cryptophytes to capture light energy in the water environment. Since the first discovered of PBP, scientists have conducted in-depth research on the structure, function and application of PBP. PBP is a water-soluble protein. It is formed by the covalent connection of apoprotein and phycobilin. According to the spectral characteristics, PBP can be divided into four types: Phycoerythrin (PE), phycocyanin (PC), allophycocyanin (APC) and phycoerythrocyanin (PEC). Through the coordination of four PBPs, more than 95% of the energy can be efficiently transmitted. PE is the beginning of the energy transfer of the PBP system. It is composed of three subunits α, β and γ, and the molecular weight is about 240 kD. Among them, the γ subunit has the function of connecting and stabilizing, so that PE can exist in a stable (αβ) 6γ form. PE can covalently connect chromophores such as phycoerythrobilin (PEB) and phycourobilin (PUB), and has a strong absorption efficiency for short-wavelength blue and green light. It enables red algae and cyanobacteria to efficiently capture and transfer light energy in the deep blue and green light environment. PE is a bright red fluorescent protein. When excited by a specific wavelength, PE will emit strong fluorescence. Food-grade PE can be used as a natural colorant in food, cosmetics and other fields. High-purified PE is combined with proteins such as biotin and monoclonal antibodies to make fluorescent probes for immunodetection and other technologies; PE can also be used as a new photosensitizer for photodynamic therapy of deep tissues. In addition, PE has also been proven to have anti-oxidant and anti-inflammatory biological activities, and has a certain therapeutic effect on Alzheimer’s disease, cancer, diabetes, liver and kidney toxicity and other diseases. But there is no doubt that PE has great potential in the field of biotechnology. The application of PE is closely related to its purity. China’s abundant red algae resources provide a large amount of raw materials for large-scale preparation of PE. However, there are many obstacles in the preparation of high-purified PE. The most commonly used column chromatography has the problem of expansion, while other purification processes are not mature. In view of the above problems, this review highlights an overview on the structure, function and purification process of PE. Then the applications of PE in optical and biological activities are reviewed and prospected. This article provides a reference for the high value processing and application of marine algae.

Integrating Suitable Linkage of Covalent Organic Frameworks into Covalently Bridged Inorganic/Organic Hybrids toward Efficient Photocatalysis.

Covalent organic frameworks (COFs) are excellent platforms with tailored functionalities in photocatalysis. There are still challenges in increasing the photochemical performance of COFs. Therefore, we designed and prepared a series of COFs for photocatalytic hydrogen generation. Varying different ratios of β-ketoenamine to imine moieties in the linkages could differ the ordered structure, visible light harvesting, and bandgap. Overall, β-ketoenamine-linked COFs exhibited much better photocatalytic activity than those COFs having both β-ketoenamine and imine moieties on account of a nonquenched excited state and more favorable HOMO level in the photoinduced oxidation reaction from the former. Specifically, after in situ growth of β-ketoenamine-linked COFs onto NH2-Ti3C2TxMXene via covalent connection, the heterohybrid showed an obvious improvement in photocatalytic H2 evolution because of strong covalent coupling, electrical conductivity, and efficient charge transfer. This integrated linkage evolution and covalent hybridization approach advances the development of COF-based photocatalysts.

Green synthesis of soluble graphene in organic solvent via simultaneous functionalization and reduction of graphene oxide with urushiol

The poor dispersion and weak interfacial interaction are the main problems in the graphene based polymer composites. The complicated modification of graphene is usually needed. In this paper, a green and facile method is reported for the synthesis of functionalized reduced graphene oxide under mild conditions. The proposed method is based on the simultaneous reduction and surface function of graphene oxide by urushiol extracted from the sap of lacquer trees. The presence of the unsaturated long alkyl chains of urushiol not only improves the dispersion of resultant graphene in various organic solvents, but also makes graphene easily form covalent connection with polymer matrix. These features endow this urushiol functionalized graphene with great potential in the construction of graphene based polymer composites.

Rational combination of covalent-organic framework and nano TiO2 by covalent bonds to realize dramatically enhanced photocatalytic activity

Rationally combining the advantage of inorganic and organic semiconductors to construct a heterojunction is an effective way to boost the photocatalytic activity of materials, while it is still a great challenge to tightly integrate these two different components together. In this work, for the first time, the TpPa-1-COF, an excellent visible-light harvesting covalent-organic frameworks (COFs), and TiO2 were combined together by covalent bonds to construct a heterojunction. The resulting TiO2-TpPa-1-COF hybrid materials show efficient photocatalytic activity under visible light irradiation. Especially, TiO2-TpPa-1-COF (1:3) exhibits the optimized photocatalytic H2 evolution rate of 11.19 mmol g−1 h-1 and apparent quantum efficiency of 7.6 % at λ = 420 nm, which is 5.3 and 3.0 times higher than the TpPa-1-COF and TiO2/TpPa-1-COF, respectively. Further investigations confirm that the covalent connection between TiO2 and TpPa-1-COF components can largely improve the transfer of photogenerated charges of COF, leading to the efficient H2 evolution activity.

Full-spectrum responsive ZrO2-based phototheranostic agent for NIR-II photoacoustic imaging-guided cancer phototherapy.

Second near-infrared (NIR-II) window responsive phototheranostic agents have a precise spatiotemporal potential for the diagnosis and treatment of cancer. In this study, a full-spectrum responsive ZrO2-based phototheranostic agent was found to achieve NIR-II photoacoustic (PA) imaging-guided tumour-targeting phototherapy. Initially, the ZrO2-based phototheranostic agent was fabricated through NaBH4 reduction to form boron-doped oxygen-deficient zirconia (ZrO2-x-B), an amino-functionalised SiO2 shell and a further covalent connection with hyaluronic acid (HA), namely, ZrO2-x-B@SiO2-HA. In the ZrO2-x-B@SiO2-HA system, the oxygen vacancy and boron doping resulted in full-spectrum absorption, enabling a high NIR-II photothermal conversion, high-resolution PA imaging ability and a remarkable production of reactive oxygen species (ROS). The surface modification of HA provided ZrO2-x-B@SiO2-HA with water dispersibility and a targeting capability for CD44 overexpressed cancer cells. Furthermore, in vitro and in vivo experiments showed that NIR-II activated ZrO2-x-B@SiO2-HA had a targeted photothermal/photodynamic effect for cancer elimination under the real-time guidance of NIR-II PAs. Hence, ZrO2-x-B@SiO2-HA displays a precise NIR-II radiation-activated phototheranostic potential for PA imaging-guided cancer-targeting photothermal/photodynamic therapy.

Redox Control of Supramolecular Polymerization Using Electroactive Ureidopyrimidones

Unlike conventional polymers, in which monomers are reacted to form strong covalent connections, supramolecular polymers are formed by linking monomers via weaker, non-covalent interactions such as H-bonds, ion-dipole interactions and so on. These imbue supramolecular polymers with unique properties since the linkages are readily broken, but also easily reformed as environmental conditions change. One particularly well-studied class of supramolecular polymers are based on the ureidopyrimidones, UPy’s, which dimerize via 4 strong, linear H-bonds in non-competitive solvents. Monomers for supramolecular polymerization can be made by linking together 2 or more UPy units with short covalent chains. Under dimerization conditions, the UPy’s link up to form longer polymeric chains. One of the useful attributes of such polymers is their self-healing ability. Application of heat or mechanical stress will readily break the monomers apart at the H-bonds, but, upon cooling or relief of stress, the bonds reform. The goal of this research is to see if electron transfer can be used as an alternative, more selective stimulus to break apart the UPy chains. As a first step in this direction, we have synthesized a known UPy monomer, 1, which is expected to polymerize at concentrations above ~20 mM in CH2Cl2. This can be verified by measuring the change in specific viscosity as a function of the concentration of 1. By adding simple UPy’s as chain terminators the degree of polymerization should decrease, with a corresponding decrease in the viscosity of solution. For this work, we plan to add our previously studied electroactive UPy’s, 2a and 2b. We have previously shown oxidation breaks apart the 2a and 2b dimers at mM concentrations in CH2Cl2. Thus, upon electrochemical oxidation, 2a or 2b will no longer be able to act as chain terminators and the linked UPy 1 should reform polymer chains. This can be detected by an increase in the viscosity of solution upon oxidation. Figure 1

A polymer-based thermal management material with enhanced thermal conductivity by introducing three-dimensional networks and covalent bond connections

With the growing challenges of modern electronics in heat dissipation, developing thermal management materials with high thermal conductivity and electrical insulation property remains an important issue for electronics. In this work, a novel three-dimensional network (3D) of boron nitride/reduced graphene oxide (BN/rGO) with covalent bond connections were fabricated by using the surface modification and ice-templated methods. The as-prepared boron nitride/reduced graphene oxide/nature rubber composites (BN/rGO/NR) possessed an enhanced through-plane thermal conductivity of 1.28 W m−1 K−1 and satisfactory electrical insulation at a low filler loading of 4.9 vol%. The results demonstrated that the covalent bond connections and three-dimensional networks of fillers greatly reduced the interfacial thermal resistance as well as phonon scatterings at the filler/filler and filler/matrix interface simultaneously. More importantly, this strategy provided a creative insight to the design of advanced thermal management materials and also presented a bright application prospect for next-generation electronic packing.

Covalent Connection of Polyaniline with MoS2 Nanosheets toward Ultrahigh Rate Capability Supercapacitors

Two-dimensional molybdenum disulfide (MoS2) is a promising electrode material for supercapacitors, attributing to attractive physical properties, outstanding electrical properties, and ultrahigh ex...