3D Carbon Frameworks for Ultrafast Charge/Discharge Rate Supercapacitors with High Energy‑Power Density

Carbon-based electric double layer capacitors(EDLCs)hold tremendous potentials due to their high-power performance and excellent cycle stability.However,the practical use of EDLCs is limited by the low energy density in aqueous electrolyte and sluggish diffusion kinetics in organic or/and ionic liquids electrolyte.Herein,3D carbon frameworks(3DCFs)constructed by interconnected nanocages(10-20 nm)with an ultrathin wall of ca.2 nm have been fabricated,which possess high specific surface area,hierarchical porosity and good conductive network.After deoxidization,the deoxidized 3DCF(3DCFDO)exhibits a record low IR drop of 0.064 V at 100 A g^−1 and ultrafast charge/discharge rate up to 10 V s^−1.The related device can be charged up to 77.4%of its maximum capacitance in 0.65 s at 100 A g^−1 in 6 M KOH.It has been found that the 3DCF-DO has a great affinity to EMIMBF4,resulting in a high specific capacitance of 174 F g^−1 at 1 A g^−1,and a high energy density of 34 Wh kg^−1 at an ultrahigh power density of 150 kW kg^−1 at 4 V after a fast charge in 1.11 s.This work provides a facile fabrication of novel 3D carbon frameworks for supercapacitors with ultrafast charge/discharge rate and high energy-power density.

Application and Progress of Confinement Synthesis Strategy in Electrochemical Energy Storage

Designing high-performance nanostructured electrode materials is the current core of electrochemical energy storage devices.Multi-scaled nanomaterials have triggered considerable interest because they effectively combine a library of advantages of each component on different scales for energy storage.However,serious aggregation,structural degradation,and even poor stability of nanomaterials are well-known issues during electrochemically driven volume expansion/contraction processes.The confinement strategy provides a new route to construct controllable internal void spaces to avoid the intrinsic volume effects of nanomaterials during the reaction or charge/discharge process.Herein,we discuss the confinement strategies and methods for energy storage-related electrode materials with a one-dimensional channel,two-dimensional interlayer,and three-dimensional space as reaction environments.For each confinement environment,the correlation between the confinement condition/structure and the behavioral characteristics of energy storage devices in the scope of metal-ion batteries(e.g.,Li-ion,Na-ion,K-ion,and Mg-ion batteries),Li-S batteries(LSBs),Zn-air batteries(ZIBs),and supercapacitors.Finally,we discussed the challenges and perspectives on future nanomaterial confinement strategies for electrochemical energy storage devices.

Optical Properties, Electronic Energy Level Structure and Electroluminescent Characteristics of Salicylaldehyde Anil Zinc

A new electroluminescent material, salicylaldehyde anil zinc （SAZ） was synthesized, which can form high quality, thermal stability, nano-scale amorphous films by vacuum evaporation. Its structure, thermal stability were characterized by infrared （IR） spectra, differential thermal analysis-thermogravimetry （DTA-TG） analysis, respectively. The optical properties of SAZ were investigated by UV absorption spectra, Photoluminescence （PL） excitation and emission spectra. The highest occupied molecular orbits （HOMO）, lowest unoccupied molecular orbits （LUMO） and optical band gap were evaluated by cyclic voltammetry curve and optical absorption band edge. The electroluminescent devices using SAZ as the emissive layer emit green light with a peak wavelength at 509 nm and a brightness of about 3.1 cd/m^2.

Functional brain imaging studies on specificity of meridian and acupoints

At present, the specificity of meridians and acupoints has been studied using functional brain imaging techniques from many standpoints, including meridians, acupoints, and sham acupoints, as well as different meridians and acupoints, coordination of acupoints, and factors influencing meridian and acupoint specificity Preliminary experimental data have demonstrated that acupuncture at meridians and acupoints is specific with regard to brain neural information. However, research findings are contradictory, which may be related to brain functional complexity, resolution of functional brain imaging techniques, and experimental design. Future studies should further improve study method, and should strictly control experimental conditions to better analyze experimental data and acquire more beneficial data. Because of its many advantages, the functional brain imaging technique is a promising method for studying meridian and acupoint specificity.

Single-Molecule Confinement Induced Intrinsic Multi-Electron Redox-Activity to Enhance Supercapacitor Performance

Aggregation of polyoxometalates(POM)is largely responsible for the reduced performance of POM-based energy-storage systems.To address this challenge,here,the precise confinement of single Keggin-type POM molecule in a porous carbon(PC)of unimodal super-micropore(micro-PC)is realized.Such precise single-molecule confinement enables sufficient activity center exposure and maximum electron-transfer from micro-PC to POM,which well stabilizes the electron-accepting molecules and thoroughly activates its inherent multi-electron redox-activity.In particular,the redox-activities and electron-accepting properties of the confined POM molecule are revealed to be super-micropore pore size-dependent by experiment and spectroscopy as well as theoretical calculation.Meanwhile,the molecularly dispersed POM molecules confined steadily in the“cage”of micro-PC exhibit unprecedented large-negative-potential stability and multiple-peak redox-activity at an ultra-low loading of~11.4 wt%.As a result,the fabricated solid-state supercapacitor achieves a remarkable areal capacitance,ultrahigh energy and power density of 443 mF cm^(-2),0.12 mWh cm^(-2)and 21.1 mW cm^(-2),respectively.This work establishes a novel strategy for the precise confinement of single POM molecule,providing a versatile approach to inducing the intrinsic activity of POMs for advanced energy-storage systems.

Research on the Best Shooting State Based on the “Three Forces” Model

The shooting state during shooting refers to the basketball’s shooting speed,shooting angle and the ball’s rotation speed.The basketball flight path is also related to these factors.In this paper,based on the three forces of Gravity,Air Resistance and Magnus Force,the“Three Forces”model is established,the Kinetic equations are derived,the basketball flight trajectory is solved by simulation,and the best shot state when shooting is obtained through the shooting percentage.Compared with the“Single Force”model that only considers Gravity,the shooting percentage of the“Three Forces”model is higher.The reason is that the Magnus Force generated by considering the basketball rotation speed is considered.Although in the“Three Forces”model,the shot speed is faster and the shot is harder,the backspin will reduce the angle of the shot and achieve the goal of saving effort.By calculating the best shot state and giving the athlete’s usual training state range,you can guide the training,thereby improving the athlete’s shooting percentage during the game.

Classical spin liquid state in a rhombic lattice metal-organic framework

Discovering more and new geometrically frustrated systems remains an active point of inquiry in fundamental physics for the existence of unusual states of matter.Here,we report spin-liquid-like behavior in a two-dimensional(2D)rhombic lattice Fe-metal-organic framework(Fe-MOF)with frustrated antiferromagnetism.This Fe-MOF exhibits a high frustration factor f=|θCW|/TN≥315,and its long-range magnetic order is suppressed down to 180 mK.Detailed theoretical calculations demonstrate strong antiferromagnetic coupling between adjacent Fe3+ions,indicating the potential of a classical spin-liquid-like behavior.Notably,a T-linear heat capacity parameter,γ,originating from electronic contributions and with magnetic field independence up to 8 T,can be observed in the specific heat capacity measurements at low-temperature,providing further proof for the spin-liquid-like behavior.This work highlights the potential of MOF materials in geometrically frustrated systems,and will promote the research of exotic quantum physics phenomena.

Highly efficient and photothermally stable CDs@ZIF-8 for laser illumination

Carbon dots(CDs),as a solid-state phosphor,have great potential for application in a new solid-state lighting device—laser diode(LD).For high efficiency LD devices,both high photoluminescence quantum yield(PLQY)and high photothermal stability of CDs are essential.Herein,yellow CDs@ZIF-8 composites with high structural stability were prepared by encapsulating CDs in zeolitic imidazolate framework-8(ZIF-8)through electrostatic adsorption between CDs and ZIF-8,in which CDs with amino groups on the surface were used as luminescent feeders and ZIF-8 was used as a protective layer matrix.The asprepared CDs@ZIF-8 not only possess a high PLQY of up to 81.17%,but also maintain a high fluorescence intensity of 100%and 80%under long-term illumination(60 min)and high temperature(478 K),respectively.The hydrogen bonding between CDs and ZIF-8 in the encapsulated structure can enhance the degree of electron cloud delocalization,which can improve the PLQY of CDs@ZIF-8.Meanwhile,CDs@ZIF-8has high photothermal stability due to the binding effect of ZIF-8 on CDs and high thermal stability of ZIF-8.The white LD device,fabricated from CDs@ZIF-8 as a phosphor in combination with 450 nm blue LD,has a color coordinate of(0.37,0.33),a color temperature of 3762 K,and a high color rendering index of 86.This study provides a new strategy for the construction of solid-state phosphors with high PLQY and high photothermal performance.

手性碳量子点的制备及其应用

手性碳量子点(CQDs)因兼具优异的荧光性质、良好的生物相容性、较低的毒性、易于功能化以及手性特征等,在催化、检测和生物医学等领域具有广阔的应用潜力。目前,通过一步法或两步法制备的手性CQDs,已应用于手性催化、手性检测、高尔基体靶向成像、选择性调控酶和蛋白活性、选择性调控细胞能量代谢和促进植物生长等领域。然而,手性CQDs的发展初露头角,需进一步完善可控合成工艺,制备高荧光量子产率的长波长手性CQDs,使其在生物医学等领域绽放异彩。

Oxygen vacancy-mediated WO_(3) phase junction to steering photogenerated charge separation for enhanced water splitting

Effective charge separation and transfer is deemed to be the contributing factor to achieve high photoelectrochemical(PEC)water splitting performance on photoelectrodes.Building a phase junction structure with controllable phase transition of WO_(3) can further improve the photocatalytic performance.In this work,we realized the transition from orthorhombic to monoclinic by regulating the annealing temperatures,and constructed an orthorhombic–monoclinic WO_(3)(o-WO_(3)/m-WO_(3))phase junction.The formation of oxygen vacancies causes an imbalance of the charge distribution in the crystal structure,which changes the W–O bond length and bond angle,accelerating the phase transition.As expected,an optimum PEC activity was achieved over the o-WO_(3)/m-WO_(3) phase junction in WO_(3)-450 photoelectrode,yielding the maximum O_(2) evolution rate roughly 32 times higher than that of pure WO_(3)-250 without any sacrificial agents under visible light irradiation.The enhancement of catalytic activity is attributed to the atomically smooth interface with a highly matched lattice and robust built-in electric field around the phase junction,which leads to a less-defective and abrupt interface and provides a smooth interfacial charge separation and transfer path,leading to improved charge separation and transfer efficiency and a great enhancement in photocatalytic activity.This work strikes out on new paths in the formation of an oxygen vacancy-induced phase transition and provides new ideas for the design of catalysts.

NUMB regulates the endocytosis and activity of the anaplastic lymphoma kinase in an isoform-specific manner

NUMB is an evolutionarily conserved protein that plays an important role in cell adhesion,migration,polarity,and cell fate determination.It has also been shown to play a role in the pathogenesis of certain cancers,although it remains controversial whether NUMB functions as an oncoprotein or tumor suppressor.Here,we show that NUMB binds to anaplastic lymphoma kinase(ALK),a receptor tyrosine kinase aberrantly activated in several forms of cancer,and this interaction regulates the endocytosis and activity of ALK.Intriguingly,the function of the NUMB-ALK interaction is isoform-dependent.While both p66-NUMB and p72-NUMB isoforms are capable of mediating the endocytosis of ALK,the former directs ALK to the lysosomal degradation pathway,thus decreasing the overall ALK level and the downstream MAP kinase signal.In contrast,the p72-NUMB isoform promotes ALK recycling back to the plasma membrane,thereby maintaining the kinase in its active state.Our work sheds light on the controversial role of different isoforms of NUMB in tumorigenesis and provides mechanistic insight into ALK regulation.

Construction of multi-homojunction TiO_(2)nanotubes for boosting photocatalytic hydrogen evolution by steering photogenerated charge transfer

As an effective means to improve charge carrier separation efficiency and directional transport,the gradient doping of foreign elements to build multi-homojunction structures inside catalysts has received wide attentions.Herein,we reported a simple and robust method to construct multi-homojunctions in black TiO_(2) nanotubes by the gradient doping of Ni species through the diffusion of deposited Ni element on the top of black TiO2 nanotubes driven by a high temperature annealing process.The gradient Ni distribution created parts of different Fermi energy levels and energy band structures within the same black TiO_(2) nanotube,which subsequently formed two series of multi-homojunctions within it.This special multi-homojunction structure largely enhanced the charge carrier separation and transportation,while the low concentration of defect states near the surface layer further inhibited carrier recombination and facilitated the surface reaction.Thus,the B-TNT-2Ni sample with the optimized Ni doping concentration exhibited an enhanced hydrogen evolution rate of~1.84 mmol·g^(−1)·h^(−1)under visible light irradiation without the assistance of noble-metal cocatalysts,~four times higher than that of the pristine black TiO_(2)nanotube array.With the capability to create multi-homojunction structures,this approach could be readily applied to various dopant systems and catalyst materials for a broad range of technical applications.

Green-emissive carbon quantum dots with high fluorescence quantum yield:Preparation and cell imaging

High fluorescence quantum yield(QY),excellent fluorescence stability,and low toxicity are essential for a good cellular imaging fluorescent probe.Green-emissive carbon quantum dots(CQDs)with many advantages,such as unique fluorescence properties,anti-photobleaching,low toxicity,fine biocompatibility and high penetration depth in tissues,have been considered as a potential candidate in cell imaging fluorescent probes.Herein,N,S-codoped green-emissive CQDs(QY=64.03%)were synthesized by the one-step hydrothermal method,with m-phenylenediamine as the carbon and nitrogen source,and L-cysteine as the nitrogen and sulfur dopant,under the optimum condition of 200℃ reaction for 2 h.Their luminescence was found to originate from the surface state.In light of the satisfactory photobleaching resistance and the low cytotoxicity,CQDs were used as a cell imaging probe for HeLa cell imaging.The results clearly indicate that cells can be labeled with CQDs,which can not only enter the cytoplasm,but also enter the nucleus through the nuclear pore,showing their broad application prospect in the field of cell imaging.

Sub-nanopores-containing N,O-codoped porous carbon from molecular-scale networked polymer hydrogel for solid-state supercapacitor

A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing molecular-scale grids(diameter~2.0 nm)allows for homogeneous N,O-codoping into the porous carbon scaffold during the pyrolysis process.A subsequent activation step produces activated porous carbons(APCs)with tailored pore structures,which renders the APCs abundant subnanopores on their surface to increase the specific capacitance as extra capacitance sites.Coupled with large specific surface area and abundant heteroatoms,the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor.The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg,which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles.Moreover,this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.

Robust Fe^(2+)-doped nickel-iron layered double hydroxide electrode for electrocatalytic reduction of hexavalent chromium by pulsed potential method

Electrocatalytic reduction of Cr(Ⅵ)to less toxic Cr(Ⅲ)is deemed as a promising technique.Conventional electrocatalytic reduction is always driven by a constant cathodic potential,which exhibits a repelling action to Cr(Ⅵ)oxyanions in wastewater and consequently suppresses reduction kinetics.In order to remarkably accelerate Cr(Ⅵ)electrocatalytic reduction,we applied a pulsed potential on an Fe^(2+)-NiFe LDH/NF electrode synthesized by in situ growth of Fe^(2+)-doped NiFe LDH nanosheets on Ni foam using a spontaneous redox reaction.Under anodic potential section,HCrO_(4)^(–) anions are adsorbed on the electrode surface and reduced to Cr(Ⅲ)by Fe^(2+).Then,Cr(Ⅲ)ions are desorbed from the electrode surface under coulombic force.The regeneration of Fe^(2+) and direct reduction of Cr(Ⅵ)are achieved under cathodic potential section.The pulsed potential can achieve complete elimination of Cr(Ⅵ)within 60 min at an initial concentration of 10 mg L^(-1),and the removal efficiency shows a 60%increase with respect to that under constant cathodic potential.

The exceedingly strong two-dimensional ferromagnetism in biatomic layer SrRuO_(3)with a critical conduction transition

In recent years,few-layer or even monolayer ferromagnetic materials have drawn a great deal of attention due to the promising integration of two-dimensional(2D)magnets into next-generation spintronic devices.The SrRuO_(3)monolayer is a rare example of stable 2D magnetism under ambient conditions,but only weak ferromagnetism or antiferromagnetism has been found.The biatomic layer SrRuO_(3)as another environmentally inert 2D magnetic system has been paid less attention heretofore.Here we study both the bi-atomic layer and monolayer SrRuO_(3)in(SrRuO_(3))n/(SrTiO_(3))m(n=1,2)superlattices in which the SrTiO3 serves as a non-magnetic and insulating space layer.Although the monolayer exhibits arguably weak ferromagnetism,we find that the bi-atomic layer exhibits exceedingly strong ferromagnetism with a Tc of 125 K and a saturation magnetization of 1.2μB/Ru,demonstrated by both superconducting quantum interference device(SQUID)magnetometry and element-specific X-ray circular dichroism.Moreover,in the bi-atomic layer SrRuO_(3),we demonstrate that random fluctuations and orbital reconstructions inevitably occurring in the 2D limit are critical to the electrical transport,but are much less critical to the ferromagnetism.Our study demonstrates that the bi-atomic layer SrRuO_(3)is an exceedingly strong 2D ferromagnetic oxide which has great potentials for applications of ultracompact spintronic devices.

Mechanistic insights into the selective photocatalytic degradation of dyes over TiO_(2)/ZSM-11

Photocatalytic degradation is a promising way to eliminate dye contaminants.In this work,a series of TiO2/ZSM-11(TZ)nanocomposites were prepared using a facile solid state dispersion method.Methyl orange(MO),methylene blue(MB),and rhodamine B(RhB)were intentionally chosen as target substrates in the photocatalytic degradation reactions.Compared to pristine TiO2,negative effect was observed on MO degradation while promoted kinetics were collected on MB and RhB over TZ composites.Moreover,a much higher photocatalytic rate was interestingly achieved on RhB than MB,which indicated that a new factor has to be included other than the widely accepted electrostatic interaction mechanism to fully understand the selective photodegradation reactions.Systematic characterizations showed that TiO2 and ZSM-11 physically mixed and maintained both the whole framework and local structure without chemical interaction.The different trends observed in surface area and the photo-absorption ability of TZ composites with reaction performance further excluded both as the promotion mechanism.Instead,adsorption energies predicted by molecular dynamics simulations suggested that differences in the adsorption strength played a critical role.This work provided a deep mechanistic understanding of the selective photocatalytic degradation of dyes reactions,which helps to rationally design highly efficient photocatalysts.

Submicrometer-scale ZnO Composite Aggregate Arrays Photoanodes for Dye-sensitized Solar Cells

Submicrometer-scale ZnO composite aggregate arrays of nanorods and nanoparticles were prepared by simple wet-chemical route and studied as dye-sensitized solar cells （DSSCs） photoanodes. The ZnO composite aggregate arrays significantly improved the efficiency of DSSCs due to their relatively high surface area, fast electron transport, and enhanced light-scattering capability. A short current density （Jsc） of 11.7 mA/cm2 and an overall solar-to-electric energy conversion efficiency （η） of 3.17% were achieved for the ZnO composite aggregate DSSCs, which were much higher than those obtained for the monodisperse aggregate DSSCs （Jsc = 6.9 mA/cm2, r/= 1.51 %） and ZnO nanorod array DSSCs （Jsc = 4.2 mA/cm2, η= 0.61%）.

Oxygen vacancy self-doped single crystal-like TiO_(2) nanotube arrays for efficient light-driven methane non-oxidative coupling

Photocatalytic non-oxidative coupling of methane(PNOCM)is a mild and cost-effective method for the production of multicarbon compounds.However,the separation of photogenerated charges and activation of methane(CH4)are the main challenges for this reaction.Here,single crystal-like TiO_(2) nanotubes(VO-p-TNTs)with oxygen vacancies(VO)and preferential orientation were prepared and applied to PNOCM.The results demonstrate that the significantly enhanced photocatalytic performance is mainly related to the strong synergistic effect between preferential orientation and VO.The preferential orientation of VO-p-TNT along the[001]direction reduces the formation of complex centers at grain boundaries as the form of interfacial states and potential barriers,which improves the separation and transport of photogenerated carriers.Meanwhile,VO provides abundant coordination unsaturated sites for CH4 chemisorption and also acts as electron traps to hinder the recombination of electrons and holes,establishing an effective electron transfer channel between the adsorbed CH4 molecule and photocatalyst,thus weakening the C–H bond.In addition,the introduction of VO broadens the light absorption range.As a result,VO-p-TNT exhibits excellent PNOCM performance and provides new insights into catalyst design for CH4 conversion.

Realization of solid-state red fluorescence and concentration-induced multicolor emission from N,B co-doped carbon dots

As a new type of luminescent material,carbon dots(CDs)have attracted increased attention for their superior optical properties in recent years.However,solidstate fluorescent CDs,especially with red emission,are still a major challenge.Here,CDs with solid-state red emission were synthesized by co-doping of N and B using the one-step microwave method.The CD powder exhibits excitation-independent solid-state red fluorescence without any dispersion matrices,with optimum solid-state fluorescence wavelength of 623 nm.The hydrogen bonding interaction in CDs is helpful for solid-state fluorescence of CDs.The IG/ID value of CDs reaches up to 3.49,suggesting their very high graphitization degree,which is responsible for their red emission.In addition,CDs show the concentration-induced multicolor emission,which is attributed to the decreased energy gap in the high concentrated CD solution.To exploit their concentration-dependent emission,CDs with changing ratio in matrices are applied as a color-converting layer on ultraviolet chip to fabricate multicolor light-emitting diodes with light coordinates of(0.33,0.38),(0.41,0.48),(0.49,0.44),and(0.67,0.33),which belong to green,yellow,orange,and red light,respectively.