One-pot co-crystallized hexanal-loaded ZIF-8/quaternized chitosan film for temperature-responsive ethylene inhibition and climacteric fruit preservation.

Controlling ethylene production and microbial infection are key factors to prolong the shelf life of climacteric fruit. Herein, a nanocomposite film, hexanal-loaded ZIF-8/CS (HZCF) with "nano-barrier" structure, was developed by a one-pot co-crystallized of ZIF-8 in situ growth on quaternized chitosan (CS) and encapsulation of hexanal into ZIF-8 via microporous adsorption. The resultant film realized the temperature responsive release of hexanal via the steric hindrance and hierarchical pore structure as "nano-barrier", which can inhibit ethylene production in climacteric fruit on demand. Based on this, the maximum ethylene inhibition rate of HZCF was up to 52.6 %. Meanwhile, the film exhibits excellent antibacterial, mechanical, UV resistance and water retention properties, by virtue of the functional synergy between ZIF-8 and CS. Contributed to the multifunctional features, HZCF prolonged the shelf life of banana and mango for at least 16 days, which is 8 days longer than that of control fruit. More strikingly, HZCF is washable and biodegradable, which is expected to replace non-degradable plastic film. Thus, this study provides a convenient novel approach to simplify the encapsulation of active molecule on metal-organic frameworks (MOFs), develops a packaging material for high-efficient freshness preservation, and helps to alleviate the survival crisis caused by food waste.

Self-triggered carboxymethyl chitosan hydrogel for the convenient sustained release of ClO2 gas with environmental stability and long-term antimicrobial effect.

Challenges associated with the storage and uncontrolled release of ClO2 gas present significant hurdles to its practical application. Herein, a clever strategy for self-triggering the sustained release of chlorine dioxide (ClO2) gas is proposed by crosslinking carboxymethyl chitosan (CMCS) with Zn2+ to construct a novel CMCS-Zn@NaClO2 gel with eco-friendly, environmental stability, and convenient, long term, and efficient antibacterial activity. The precursor (NaClO2) in the CMCS solution was alkaline and triggered by the acidic Zn(NO3)2·6H2O solution to achieve sustained self-triggering ClO2 release. The ClO2 gas self-release could be sustained on demand at different temperatures for at least 20 days due to the environmental structure stability of the gel. The hydrogels showed an increase in pore size after sustained release. Molecular dynamics simulations showed the spontaneous release of ClO2 gas at room temperature and the contraction of the CMCS agglomeration, which were consistent with the macroscopic behaviour. The gel displayed a long-acting and high antibacterial efficacy, resulting in a bacteria-killing rate of over 99.9% (inhibitory concentrations of 2.5 mg mL-1 against E. coli and 0.16 mg mL-1 against S. aureus). The hydrogels could effectively extend the shelf life of fruits and demonstrated an excellent wide range of antibacterial properties. This work provides a new approach to solving the storage difficulty of ClO2 gas and offers a fresh perspective on the design of materials with convenient self-triggering release by a precursor, as well as the relationship between the material microstructure and sustained-release behaviour.

Interlayer Engineering of VS2 Nanosheets via In Situ Aniline Intercalative Polymerization toward Long-Cycling Magnesium-Ion Batteries.

Rechargeable magnesium batteries (RMBs) show great potential in large-scale energy storage systems, due to Mg2+ with high polarity leading to strong interactions within the cathode lattice, and the limited discovery of functional cathode materials with rapid kinetics of Mg2+ diffusion and desirable cyclability retards their development. Herein, we innovatively report the confined synthesis of VS2/polyaniline (VS2/PANI) hybrid nanosheets. The VS2/PANI hybrids with expanded interlayer spacing are successfully prepared through the exfoliation of VS2 and in situ polymerization between VS2 nanosheets and aniline. The intercalated PANI increases the interlayer spacing of VS2 from 0.57 to 0.95 nm and improves its electronic conductivity, leading to rapid Mg-ion diffusivity of 10-10-10-12 cm2 s-1. Besides, the PANI sandwiched between layers of VS2 is conducive to maintaining the structural integrity of electrode materials. Benefiting from the above advantages, the VS2/PANI-1 hybrids present remarkable performance for Mg2+ storage, showing high reversible discharge capacity (245 mA h g-1 at 100 mA g-1) and impressive long lifespan (91 mA h g-1 after 2000 cycles at 500 mA g-1). This work provides new perspectives for designing high-performance cathode materials based on layered materials for RMBs.

Controlled Synthesis of Flower-like Hierarchical NiCo-Layered Double Hydroxide Integrated with Metal-Organic Framework-Derived Co@C for Supercapacitors.

Layered double hydroxides (LDHs) have come to the foreground recently, considering their unique layered structure and short ion channels when they act as electrode materials for supercapacitors (SCs). However, due to their poor rate and cycle performance, they are not highly sought after in the market. Therefore, a flower-like hierarchical NiCo-LDH@C nanostructure with flake NiCo-LDH anchored on the carbon skeleton has emerged here, which is constructed by calcination and hydrothermal reaction and applying flake ZIF-67 as a precursor. In this structure, NiCo-LDH grows outward with abundant and homogeneously distributed Co nanoparticles on Co@C as nucleation sites, forming a hierarchical structure that is combined tightly with the carbon skeleton. The flower-like hierarchical nanostructures formed by the composite of metal-organic frameworks (MOFs) and LDHs have successfully enhanced the cycle and rate performance of LDH materials on the strength of strong structural stability, large specific surface area, and unique cooperative effect. The NiCo-LDH@C electrode displays superb electrochemical performance, with a specific capacitance of 2210.6 F g-1 at 1 A g-1 and 88.8% capacitance retention at 10 A g-1. Furthermore, the asymmetric supercapacitor (ASC) constructed with NiCo-LDH@C//RGO reveals a remarkable energy density of 45.02 W h kg-1 with a power density of 799.96 W kg-1. This project aims to propose a novel avenue to exploit NiCo-LDH electrode materials and provide theory and methodological guidance for deriving complex structures from MOF derivatives.

Electronic structure engineering on NiSe2 micro-octahedra via nitrogen doping enabling long cycle life magnesium ion batteries.

Multivalent ion batteries have attracted great attention because of their abundant reserves, low cost and high safety. Among them, magnesium ion batteries (MIBs) have been regarded as a promising alternative for large-scale energy storage device owing to its high volumetric capacities and unfavorable dendrite formation. However, the strong interaction between Mg2+ and electrolyte as well as cathode material results in very slow insertion and diffusion kinetics. Therefore, it is highly necessary to develop high-performance cathode materials compatible with electrolyte for MIBs. Herein, the electronic structure of NiSe2 micro-octahedra was modulated by nitrogen doping (N-NiSe2) through hydrothermal method followed by a pyrolysis process and this N-NiSe2 micro-octahedra was used as cathode materials for MIBs. It is worth noting that N-NiSe2 micro-octahedra shows more redox active sites and faster Mg2+ diffusion kinetics compared with NiSe2 micro-octahedra without nitrogen doping. Moreover, the density functional theory (DFT) calculations indicated that the doping of nitrogen could improve the conductivity of active materials on the one hand, facilitating Mg2+ ion diffusion kinetics, and on the other hand, nitrogen dopant sites could provide more Mg2+ adsorption sites. As a result, the N-NiSe2 micro-octahedra cathode exhibits a high reversible discharge capacity of 169 mAh g-1 at the current density of 50 mA g-1, and a good cycling stability over 500 cycles with a maintained discharge capacity of 158.5 mAh g-1. This work provides a new idea to improve the electrochemical performance of cathode materials for MIBs by the introduction of heteroatom dopant.

Rationally designed Mn2O3@ZnMn2O4/C core-shell hollow microspheres for aqueous zinc-ion batteries.

Manganese-based oxides are common cathode materials for aqueous zinc ion batteries (AZIBs) because of their great capacity and high working voltage. However, the sharp decline of capacity caused by the dissolution of manganese-based cathode materials and the low-rate performance restrict their development. To address these problems, unique core-shell structured Mn2O3@ZnMn2O4/C hollow microspheres are reported as an ideal cathode material for AZIBs. Benefiting from the hollow structure, the zeolitic imidazolate framework (ZIF)-derived carbon and ZnMn2O4. Its application in AZIBs as the cathode demonstrates its satisfactory rate performance, high cycle stability, and excellent reversibility. Its high reversible capacity is remarkable, which reaches its maximum of 289.9 mA h g-1 at 200 mA g-1 and maintains a capacity of 203.5 mA h g-1 after cycling for 700 times at 1000 mA g-1. These excellent performances indicate that this material is a potential cathode material of AZIBs.

Enhanced Li-Ion Diffusion and Cycling Stability of Ni-Free High-Entropy Spinel Oxide Anodes with High-Concentration Oxygen Vacancies.

High-entropy oxide (HEO) is an emerging type of anode material for lithium-ion batteries with excellent properties, where high-concentration oxygen vacancies can effectively enhance the diffusion coefficient of lithium ions. In this study, Ni-free spinel-type HEOs ((FeCoCrMnZn)3O4 and (FeCoCrMnMg)3O4) were prepared via ball milling, and the effects of zinc and magnesium on the concentration of oxygen vacancy (OV), lithium-ion diffusion coefficient (DLi+), and electrochemical performance of HEOs were investigated. Ab initio calculations show that the addition of zinc narrows down the band gap and thus improves the electrical conductivity. X-ray photoelectron spectroscopy (XPS) results show that (FeCoCrMnZn)3O4 (42.7%) and (FeCoCrMnMg)3O4 (42.5%) have high OV concentration. During charge/discharge, the OV concentration of (FeCoCrMnZn)3O4 is higher than that of (FeCoCrMnMg)3O4. The galvanostatic intermittent titration technique (GITT) results show that the DLi+ value of (FeCoCrMnZn)3O4 is higher than that of (FeCoCrMnMg)3O4 during charge and discharge. All of that can improve its specific discharge capacity and enhance its cycle stability. (FeCoCrMnZn)3O4 achieved a discharge capacity of 828.6 mAh g-1 at 2.0 A g-1 after 2000 cycles. This work provides a deep understanding of the structure and performance of HEO.

Enhanced antibacterial effect and biodegradation of coating via dual-in-situ growth based on carboxymethyl cellulose.

The lack of antimicrobial effect of commercial paper coating for food packaging makes it difficult to prevent food spoilage and harms the environment by non-biodegradation. Herein, carboxymethyl cellulose (CMC) provides negatively charged sites for anchoring Ag+ and Zn2+ to grow AgNPs and ZIF-8 in situ on its molecular chains. The ZIF-8/AgNPs@CMC paper coating has excellent synergistic antibacterial activity to prolong the shelf-life of food. It not only has good thermal stability but binds closely to the paper and its adhesion force reaches 628.9 nN. Besides, the ZIF-8/AgNPs@CMC coated paper has better mechanical properties, water vapor barrier, and resists water solubility. Interestingly, due to the confinement effect of ZIF-8, the cumulative release of AgNPs after 168 h is only 2.66 % to avoid possible food safety risks. Especially, the coating can be almost biodegraded in the soil after 30 days, which provides the possibility to replace the non-biodegradable coatings in food packaging.

Quantifying stiffness and forces of tumor colonies and embryos using a magnetic microrobot.

Stiffness and forces are two fundamental quantities essential to living cells and tissues. However, it has been a challenge to quantify both 3D traction forces and stiffness (or modulus) using the same probe in vivo. Here, we describe an approach that overcomes this challenge by creating a magnetic microrobot probe with controllable functionality. Biocompatible ferromagnetic cobalt-platinum microcrosses were fabricated, and each microcross (about 30 micrometers) was trapped inside an arginine-glycine-apartic acid-conjugated stiff poly(ethylene glycol) (PEG) round microgel (about 50 micrometers) using a microfluidic device. The stiff magnetic microrobot was seeded inside a cell colony and acted as a stiffness probe by rigidly rotating in response to an oscillatory magnetic field. Then, brief episodes of ultraviolet light exposure were applied to dynamically photodegrade and soften the fluorescent nanoparticle-embedded PEG microgel, whose deformation and 3D traction forces were quantified. Using the microrobot probe, we show that malignant tumor-repopulating cell colonies altered their modulus but not traction forces in response to different 3D substrate elasticities. Stiffness and 3D traction forces were measured, and both normal and shear traction force oscillations were observed in zebrafish embryos from blastula to gastrula. Mouse embryos generated larger tensile and compressive traction force oscillations than shear traction force oscillations during blastocyst. The microrobot probe with controllable functionality via magnetic fields could potentially be useful for studying the mechanoregulation of cells, tissues, and embryos.

Hybridization of carboxymethyl chitosan with bimetallic MOFs to construct renewable metal ion "warehouses" with rapid sterilization and long-term antibacterial effects.

Pathogens transmitted through the water environment pose a great threat to human health. Hence developing more reliable and efficient antibacterial materials to eliminate bacterium in water environments is urgent. Herein, we posed a novel strategy of interweaving carboxymethyl chitosan (CMCS) and Ag/Cu-MOFs to construct renewable Ag/Cu-BTC@CMCS composite beads with rapid sterilization, long-term antibacterial effects and high biosafety. Characterizations revealed that CMCS and bimetallic MOFs act as the "warehouses" of metal ions and played key roles in anchoring, storage, delivery, and controlled release of metal ions. The synergistic antibacterial effect achieved by the combination of Ag+ and Cu2+ provides the composite beads with high antibacterial efficiency, resulting in low minimum inhibitory concentrations (0.32 mg/mL against E. coli and 0.16 mg/mL against S. aureus) and over 99.9 % bacteria killing rate. Benefiting from the rapid release of metal ions from polymer chains and the long-term release from MOFs, the composite beads can effectively sterilize the simulated swimming pool water in 2 h and persistently inhibit bacterial reproduction over 48 h, and show a safe level of residual heavy metals because of the chelation of CMCS. This work provides new insights and promises a strategy for the design and commercial application of novel water fungicides.

Polysaccharides synergistic boosting drug loading for reduction pesticide dosage and improve its efficiency.

Overuse of pesticides is an urgent issue to be solved in sustainable agriculture. Based on the synergistic drug loading effect of ß-cyclodextrin (ß-CD) encapsulation and alginate (Alg) cross-linking, a new environment-responsive drug delivery system (TMX-loaded Alg/ß-CD) was constructed. The relationship between carrier structure and solubility of thiamethoxam (TMX) was researched by molecular simulation. ß-CD has good binding affinity with TMX, which can increase TMX solubility by 40 %. Further co-loading with alginate could double the drug loading of the cyclodextrin inclusion complex up to 41 %. TMX-loaded Alg/ß-CD exhibits excellent environment-responsive controlled-release performance, and TMX sustained release time is 7.5 times longer than that of commercial agents. The pest control efficacy of TMX-loaded Alg/ß-CD is 20 days longer than that of commercial TMX, and the crops has no pesticide residues after using. This study provides a promising strategy for the commercial application of polysaccharide in pest control and pesticide reduction.

Synthetic Retinoid Kills Drug-Resistant Cancer Stem Cells via Inducing RARγ-Translocation-Mediated Tension Reduction and Chromatin Decondensation.

A recently developed synthetic retinoid abrogates proliferation and induces apoptosis of drug-resistant malignant-cancer-stem-cell-like cells. However, the underlying mechanisms of how the synthetic retinoid induces cancer-stem-cell-like cell tumor-repopulating cell (TRC) apoptosis are elusive. Here, it is shown that although the retinoid and conventional anticancer drugs cisplatin, all-trans retinoic acid, and tazarotene all inhibit cytoskeletal tension and decondense chromatin prior to inducing TRC apoptosis, half-maximal inhibitory concentration of the retinoid is 20-fold lower than those anticancer drugs. The synthetic retinoid induces retinoic acid receptor gamma (RARγ) translocation from the nucleus to the cytoplasm, leading to reduced RARγ binding to Cdc42 promoter and Cdc42 downregulation, which decreases filamentous-actin (F-actin) and inhibits cytoskeletal tension. Elevating F-actin or upregulating histone 3 lysine 9 trimethylation decreases retinoid-induced DNA damage and apoptosis of TRCs. The combinatorial treatment with a chromatin decondensation molecule and the retinoid inhibits tumor metastasis in mice more effectively than the synthetic retinoid alone. These findings suggest a strategy of lowering cell tension and decondensing chromatin to enhance DNA damage to abrogate metastasis of cancer-stem-cell-like cells with high efficacy.

Controllable construction of hierarchically porous carbon composite of nanosheet network for advanced dual-carbon potassium-ion capacitors.

Benefitting from the abundance and inexpensive nature of potassium resources, potassium-ion energy storage technology is considered a potential alternative to current lithium-ion systems. Potassium-ion capacitors (PICs) as a burgeoning K-ion electrochemical energy storage device, are capable of delivering high energy at high power without sacrificing lifespan. However, owing to the sluggish kinetics and significant volume change induced by the large K+-diameter, matched electrode materials with good ion accessibility and fast K+ intercalation/deintercalation capability are urgently desired. In this work, pine needles and graphene oxide (GO) are utilized as precursors to fabricate oxygen-doped activated carbon/graphene (OAC/G) porous nanosheet composites. The introduction of GO not only induces the generation of interconnected nanosheet network, but also increases the oxygen-doping content of the composite, thus expanding the graphite interlayer spacing. Experimental analysis combined with first-principle calculations reveal the transport/storage mechanism of K+ in the OAC/G composite anode, demonstrating that the high surface area, sufficient reactive sites, enlarged interlayer distance and open channels in the porous nanosheet network contribute to rapid and effective K+ diffusion and storage. When incorporated with pine needle-activated carbon as cathode, the assembled dual-carbon PICs can function at a high voltage of 5 V, exhibiting a high energy density of 156.7 Wh kg-1 at a power density of 500 W kg-1 along with a satisfied cycle life, which highlights their potential application in economic and advanced PICs.

An improved bioinspired strategy to construct nitrogen and phosphorus dual-doped network porous carbon with boosted kinetics potassium ion capacitors.

Potassium-ion capacitors (PICs) have drawn appreciable attention because PICs can masterly integrate the virtues of the high energy density of battery-type anode and high power density of capacitor-type cathode. However, the sanguine scenario involves the incompatible capacity and sluggish kinetics in the PIC device. Herein, we report the synthesis of nitrogen and phosphorus-doped network porous carbon materials (NPMCs) via a self-sacrifice template strategy, which possesses a desired three-dimensional structure and prosperous electrochemical properties for K+ storage capacity. The obtained hierarchical porous carbon delivers a high reversible capacity of 420 mA h g-1 at 0.05 A g-1 and good cycling performance owing to its high concentration of reversible carbon defects and strong charge transfer kinetics. As expected, an advanced PIC device was assembled with a working voltage as high as 4.5 V, delivering an extraordinary energy density of 81.6 W h kg-1 as well as a splendid long life. Systematic characterization analysis combined with density functional theory calculations indicates that the strategy for preparing PIC devices with outstanding performance in this work can provide new insights for the development of PICs for an extensive range of applications.

Micromechanical force promotes aortic valvular calcification.

OBJECTIVE: Calcified aortic valvular disease is known as an inflammation-related process related to force. The purpose of this study was to determine whether micromechanical force could induce valve calcification of porcine valvular interstitial cells and to examine the role of integrin αvß3 in valvular calcification by using a novel method: magnetic twisting cytometry. METHODS: Porcine valvular interstitial cells were cultured in vitro, and micromechanical force was applied to porcine valvular interstitial cells using magnetic twisting cytometry. Changes in calcification-related factors osteopontin and RUNX2 were detected. By using the calcification medium, the optimal magnetic twisting cytometry parameters for inducing valvular interstitial cell calcification were determined, and a magnetic twisting cytometry calcification promotion model was established. The role of αvß3 in calcification was studied by using αvß3 antagonists to block the function of αvß3. RESULTS: Reverse transcription polymerase chain reaction assays showed that the expression of osteopontin was enhanced 30 minutes after 25G-1Hz 5 minutes of stimulation. Western blotting assays showed that the expression of osteopontin and RUNX2 was upregulated 24 hours after 25G-1Hz 5 minutes of stimulation. The optimal magnetic twisting cytometry parameter for inducing porcine valvular interstitial cell calcification was 25G-2Hz for 10 minutes. The expression of osteopontin and RUNX2 decreased significantly after the addition of αvß3 antagonist. Clinically, patients with bicuspid aortic valves had high expression of RUNX2 and ß3 in the aortic valve, and ß3 significantly correlated with RUNX2. CONCLUSIONS: By using magnetic twisting cytometry, we established a porcine valvular interstitial cell calcification model by micromechanical force stimulation and obtained the optimal parameters. Integrin αvß3 plays a key role in the aortic valve calcification process.

Polyvinylpyrrolidone assisted transformation of Cu-MOF into N/P-co-doped Octahedron carbon encapsulated Cu3P nanoparticles as high performance anode for lithium ion batteries.

The large volume expansion and poor electrical conductivity of copper phosphide (Cu3P) during the cycle limit their further application as anode of lithium-ion batteries. Therefore, polyvinylpyrrolidone (PVP) modified Cu3(BTC)2-derived (BTC = 1, 3, 5-Benzentricarboxylic acid) in-situ N/P-co-doped Octahedron carbon encapsulated Cu3P nanoparticles (Cu3P@NPC) are successfully prepared through a two-step process of carbonization and phosphating. The N/P-co-doped Octahedron carbon matrix improves the conductivity of Cu3P and moderates the volume expansion during the lithiation/delithiation process. Meanwhile, the interaction between the Cu3P and the doped carbon matrix is methodically explored by using density functional theory (DFT). Through the analysis of the partial charge density, the density of states and the Bader charge, and the calculation results verify the correctness of the experimental observation results, that is, Cu3P@NPC has good electrochemical performance. The results show that Cu3P@NPC, as the anode of Lithium-ion batteries, has excellent electrochemical performance: it exhibits satisfactory rate performance (251.9 mAh g-1 at 5.0 A g-1) and excellent cycle performance (336.4 mAh g-1 at 1 A g-1 over 1000 cycles). This article provides an effective strategy for the encapsulation of metal phosphide nanoparticles in a doped carbon matrix.

Effects of forces on chromatin.

Chromatin is a unique structure of DNA and histone proteins in the cell nucleus and the site of dynamic regulation of gene expression. Soluble factors are known to affect the chromatin structure and function via activating or inhibiting specific transcription factors. Forces on chromatin come from exogenous stresses on the cell surface and/or endogenous stresses, which are regulated by substrate mechanics, geometry, and topology. Forces on chromatin involve direct (via adhesion molecules, cytoskeleton, and the linker of nucleoskeleton and cytoskeleton complexes) and indirect (via diffusion and/or translocation processes) signaling pathways to modulate levels of chromatin folding and deformation to regulate transcription, which is controlled by histone modifications and depends on magnitude, direction, rate/frequency, duration, and modes of stresses. The rapid force transmission pathway activates multiple genes simultaneously, and the force may act like a "supertranscription factor." The indirect mechanotransduction pathways and the rapid force transmission pathway together exert sustained impacts on the chromatin, the nucleus, and cell functions.

Carbon defects applied to potassium-ion batteries: a density functional theory investigation.

Functionalized carbon nanomaterials are potential candidates for use as anode materials in potassium-ion batteries (PIBs). The inevitable defect sites in the architectures significantly affect the physicochemical properties of the carbon nanomaterials, thus defect engineering has recently become a vital research area for carbon-based electrodes. However, one of the major issues holding back its further development is the lack of a complete understanding of the effects accounting for the potassium (K) storage of different carbon defects, which have remained elusive. Owing to pressing research demands, the construction strategies, adsorption difficulties, and structure-activity relationships of the carbon defect-involved reaction centers for the K adsorption are systematically summarized using first principles calculations. Carbon defects affect the ability to trap K by affecting the geometry, charge distribution, and conductive behavior of the carbon surface. The results show that carbon doping with pyridinic-N, pyrrolic-N, and P defect sites tend to act as trapping K sites because of electron-deficient sites. However, graphite-N and sulfur doping are less capable of trapping K. In addition, it has been proved using calculations that the defects can inhibit the growth of the K dendrite. Finally, using the molten salt method, we prepared the undoped and nitrogen-doped carbon materials for comparison, verifying the results of the calculation.

Design of a Scalable Dendritic Copper@Ni2+, Zn2+ Cation-Substituted Cobalt Carbonate Hydroxide Electrode for Efficient Energy Storage.

Design and fabrication of novel electrode materials with excellent specific capacitance and cycle stability are urgent for advanced energy storage devices, and the combinability of multiple modification methods is still insufficient. Herein, Ni2+, Zn2+ double-cation-substitution Co carbonate hydroxide (NiZnCo-CH) nanosheets arrays were established on 3D copper with controllable morphology (3DCu@NiZnCo-CH). The self-standing scalable dendritic copper offers a large surface area and promotes fast electron transport. The 3DCu@NiZnCo-CH electrode shows a markedly improved electrochemical performance with a high specific capacity of ∼1008 C g-1 at 1 A g-1 (3.2, 2.83, and 1.26 times larger than Co-CH, ZnCo-CH, and NiCo-CH, respectively) and outstanding rate capability (828.8 C g-1 at 20 A g-1) due to its compositional and structural advantages. Density functional theory (DFT) calculation results illustrate that cation doping adjusts the adsorption process and optimizes the charge transfer kinetics. Moreover, an aqueous hybrid supercapacitor based on 3DCu@NiZnCo-CH and rGO demonstrates a high energy density of 42.29 Wh kg-1 at a power density of 376.37 W kg-1, along with superior cycling performance (retained 86.7% of the initial specific capacitance after 10,000 cycles). Impressively, these optimized 3DCu@NiZnCo-CH//rGO devices with ionic liquid can be operated stably in a large potential range of 4 V with greatly enhanced energy density and power capability (110.12 Wh kg-1 at a power density of 71.69 W kg-1). These findings may shed some light on the rational design of transition-metal compounds with tunable architectures by multiple modification methods for efficient energy storage.

A self-matching, ultra-fast film forming and washable removal bio-crosslinked hydrogel films for perishable fruits.

Spoilage of food has aggravated the issue of food shortage worldwide. Here, we report a strategy for ultrafast hydrogel film forming within 10 s on fruit surfaces with good self-matching, washable removal and preservative property. This carboxymethyl chitosan (CMCS)/tannic acid (TA) hydrogel film (CTHF) is fabricated by bio-material of CMCS and TA via in-situ rapidly crosslinking with high-density hydrogen bonds. Simply blending TA and CMCS solution at room temperature can form CTHF with different roughness (Ra: ranges from 123 to 1.55 nm) on different fruit surfaces, so as to perfectly match the hydrogel protective layer of pericarp. The CTHF slows down fruit decay by its outstanding antioxidant and antibacterial activity. It is soluble and easily removed (within 3-5 min) by washing without environmental pollution and food safety issues. As natural polymer, CTHF shows high promise as sustainable substitutes for conventional plastics packing because of its non-toxic, edible, biodegradable, and environmentally friendly.