Rare-earth ion-doped garnets with excellent luminescent properties show great potential for temperature sensing,displays,and nondestructive detection.However,their limited luminescent modes and low photoluminescence q...Rare-earth ion-doped garnets with excellent luminescent properties show great potential for temperature sensing,displays,and nondestructive detection.However,their limited luminescent modes and low photoluminescence quantum yields(PLQY)restrict further applications.In this study,we synthesized Al^(3+),Er^(3+)-co-doped Gd_(3)Ga_(5)O_(12) garnets with multimode luminescence via a high-temperature solid-state method.Notably,the preferential substitution of Al^(3+)ion at octahedral-coordinated GaI sites significantly enhanced the charge density and electron transition probability,achieving a PLQY enhancement of the downshifting luminescence from 35.1%to 68.5%.Al^(3+)ion also influences electron relaxation during up-conversion luminescence,resulting in a color shift from red to yellow to green.Additionally,Al^(3+)incorporation increased the photoelectric conversion efficiency of light-emitting diodes from 2.9%to 6.3%and improved temperature sensing sensitivity from 2.7%to 5.1%K⁻1.This work provides new insights into the photophysical mechanisms and underscores the key role of Al^(3+)ion in optimizing the optical properties of garnet-based materials.展开更多
Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N c...Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N catalysis.Monosubstitu-tion C—N bond formation reaction catalyzed by K_(2)CO_(3) also gave novel enol-based target products.This method is simple and mild,with good chemoselectivity,excellent substrate compatibility and tolerance for various functional groups,and achieves gram-scale synthesis.The reaction is a nucleophilic substitution process without the involvement of free radicals.展开更多
In this work,Ga-doped Ce RhIn_(5) single crystals are grown by In/Ga flux method.Single-crystal X-ray diffraction,magnetic susceptibility,specific heat,and neutron diffraction measurements are utilized to characterize...In this work,Ga-doped Ce RhIn_(5) single crystals are grown by In/Ga flux method.Single-crystal X-ray diffraction,magnetic susceptibility,specific heat,and neutron diffraction measurements are utilized to characterize the sample quality and the antiferromagnetic transition temperature T_(N).By substituting In with Ga,T_(N) is slightly decreased,but the antiferromagnetic transition peaks in magnetic susceptibility and specific heat measurements are obviously broadened by external field along c-axis.By comparing with Zn-doped Ce RhIn_(5),it can be concluded that T_(N) is dominated by electron density,and the stiffness of antiferromagnetic transition is obviously reduced by Ga substitution.The substitution effects of Ga are possibly caused by forming heterogeneous local structures,which avoids quantum critical point,superconductivity,and non-Fermi liquid states.Investigations on Gadoped Ce RhIn_(5) help to comprehend the chemical substitution effects in Ce RhIn_(5),and the interaction between heterogeneous structure and long-range antiferromagnetic states.展开更多
Perovskite barium titanate(BaTiO3)demonstrates exceptional dielectric properties as a promising microwave-absorbing(MA)material.Leveraging structural flexibility of perovskites,magnetic components can be incorporated ...Perovskite barium titanate(BaTiO3)demonstrates exceptional dielectric properties as a promising microwave-absorbing(MA)material.Leveraging structural flexibility of perovskites,magnetic components can be incorporated at A/B-sites to enhance MA performance,yet the fundamental disparity in MA mechanisms between A/B-site magnetic doping remains elusive.Herein,nickel-doped BaTiO3 perovskites were systematically synthesized through precise adjustment of the Ba/Ti molar ratio to achieve both A-site(Ni_(x)Ba_(1−x)TiO_(3),N_(x)BTO)and B-site(BaTi_(1−x)Ni_(x)O_(3),BTN^(x)O)substitutions(0≤x≤0.1)via a simple one-step hydrothermal method.Notably,A-site Ni^(2+)substitution in N_(x)BTO induced superior magnetic loss(tanδμ=0.39)attributed to eddy-current dissipation,while B-site doping in BTN^(x)O achieved higher dielectric loss(tanδε=0.49).The N0.1BTO sample exhibited optimal MA performance with a remarkable minimum reflection loss(RLmin)of−44.39 dB and broad effective absorption bandwidth(EAB=8.66 GHz)covering the Ku-band and 67%X-band.Multimodal analysis revealed synergistic interactions among multiple reflection and scattering,multi-polarization relaxation,natural resonance,and eddy currents.In contrast,BTN0.01O demonstrated deeper RLmin(−50.88 dB)but narrower EAB(3.33 GHz)governed by dielectric mechanisms.Structural characterization indicated A-site doping induced lattice distortion,reduced unit-cell volume,and optimized oxygen vacancy distribution,synergistically balancing magneto-dielectric parameters.Conversely,B-site substitution increased oxygen vacancy concentration and carrier mobility while amplifying dielectric fluctuations.The spatial occupation preference of A/B dopants(A-site and B-site)governs lattice symmetry breaking,consequently establishing structure-property relationships and underpinning the material’s tunable dielectric behavior and magnetic phenomena.This work proposes a site-selective doping strategy for designing high-performance perovskite MA materials through magneto-dielectric equilibrium optimization.展开更多
Metal oxides as support for constructing precious metal single-atom catalysts hold great promise for a wide range of industrial applications,but achieving a high-loading of thermally stable metal single atoms on such ...Metal oxides as support for constructing precious metal single-atom catalysts hold great promise for a wide range of industrial applications,but achieving a high-loading of thermally stable metal single atoms on such supports has been challenging.Herein,we report an innovative strategy for the fabrication of high-density single-atoms(Rh,Ru,Pd)catalysts on CaAl-layered double hydroxides(CaAl-LDH)via isomorphous substitution.The Rh species have occupied Ca^(2+)vacancies within CaAl-LDH laminate by ion-exchange,facilitating a substantial loading of isolated Rh single-atoms.Such catalysts displayed superior performance in the selective hydrogenation to quinoline,pivotal for liquid organic hydrogen storage,and the universality for the hydrogenation of N-heterocyclic aromatic hydrocarbons was also verified.Combining the experimental results and density functional theory calculations,the pathway of quinoline hydrogenation over Rh1CaAl-LDH was proposed.This synthetic strategy marks a significant advancement in the field of single-atom catalysts,expanding their horizons in green chemical processes.展开更多
Donor-acceptor(D-A)compounds are particularly important in optoelectronic and biological applications.However,they are normally synthesized in the presence of transition metal catalysts.Herein,we report a metal-free m...Donor-acceptor(D-A)compounds are particularly important in optoelectronic and biological applications.However,they are normally synthesized in the presence of transition metal catalysts.Herein,we report a metal-free method by a complexmediated nucleophilic aromatic substitution of aryl nitriles with amines.The method can lead to rich D-A type aggregation-induced emission luminogens(AIEgens)with tunable properties.They emit from deep-blue to yellow-green and possess high photoluminescence quantum yields up to 70.5%in the aggregate state.Interestingly,the suppression of intramolecular flapping is proved to play an indispensable role in the AIE behavior,which is different from the mechanism met in other AIEgens.Moreover,the biocompatible AIEgens possess specific staining of lipid droplets in HeLa cells and the superiority of identifying fatty liver over traditional Oil Red O staining is exhibited.展开更多
Living cationic polymerization of 4-acetoxystyrene(STO)was conducted in CH_(2)Cl_(2) at-15℃ using a dicumyl chloride(DCC)/SnCl_(4)/nBu_(4)NBr initiating system.Impurity moisture initiation was inhibited by adding pro...Living cationic polymerization of 4-acetoxystyrene(STO)was conducted in CH_(2)Cl_(2) at-15℃ using a dicumyl chloride(DCC)/SnCl_(4)/nBu_(4)NBr initiating system.Impurity moisture initiation was inhibited by adding proton trap 2,6-di-tert-butylpyridine(DTBP),and the controlled initiation of DCC was confirmed by ^(1)H nuclear magnetic resonance(^(1)H-NMR)spectroscopy and matrix-assisted laser desorption ionization time-offlight mass(MALDI-TOF-MS)spectrometry.The polymerization kinetics were analyzed to for optimizing the polymerization rate.Allyl-telechelic PSTOs(allyl-PSTO-allyl)with molecular weight(Mn)range of 3540–7800 g/mol and narrow molecular weight dispersity(Mw/Mn)about 1.25 were prepared through nucleophilic substitution with allyltrimethylsilane(ATMS)at approximately 40%monomer conversion.The experimental results indicate that the substitution efficiency of ATMS increased with higher ATMS concentration,temperature,and extended reaction time.Nearly unity ally-functionality for allyl-PSTO-allyl was achieved by adding sufficient SnCl_(4) prior to the substitution.展开更多
Understanding the molecular relevance of metabolic rate(MR)is crucial for unveiling the mechanisms driving the evolution of animals.In this study,we investigated the association between mitochondrial DNA characteristi...Understanding the molecular relevance of metabolic rate(MR)is crucial for unveiling the mechanisms driving the evolution of animals.In this study,we investigated the association between mitochondrial DNA characteristics and both resting and maximal MRs in conjunction with life-history traits among 139 species of teleost fish,We gathered fish MR data from various sources and procured sequences of 13 mitochondrial protein-encoding genes.We calculated the absolute substitution rate for entire nucleotide sequences and 4-fold degenerate sites of each gene,along with encoding amino acid sequences.Using the phylogenetic comparative method,we then explored the associations between MR and mitochondrial DNA absolute substitution rate.Additionally,we screened MR-associated single nucleotide variants in mitochondrial DNA.The findings indicate no positive correlation between MRs and any substitution rate values of both combined sequences and individual mitochondrial protein-coding genes,refuting the MR hypothesis.Instead,both maximum body size and longevity correlated negatively with molecular substitution rates,suggesting their influences on both mutation and fixation within mitochondrial genes in fish.Results also revealed significant correlations between base variation at ATP6_169 and both resting MR and maximum MR,identifying the unique ATP6_169G in Scombridae fish,which results in an extremely low isoelectric point(pl)value of the ATP6 protein.Considering its functional significance,the ATP6_169G in Scombridae fish might link to their lifestyle characterized by fast locomotion and high metabolic demands alongside a slower molecular evolutionary rate.展开更多
Fluorine(F)substitution in polymers modulates both molecular energy levels and film morphology;however,its impact on exciton–vibrational coupling and molecular reorganization energy is often neglected.Herein,we syste...Fluorine(F)substitution in polymers modulates both molecular energy levels and film morphology;however,its impact on exciton–vibrational coupling and molecular reorganization energy is often neglected.Herein,we systematically investigated F-modified polymers(PBTA-PSF,PBDB-PSF)and their nonfluorinated counterparts(PBTA-PS,PBDB-PS)through simulations and experiments.We found that F atoms effectively lower the vibrational frequency of the molecular skeleton and suppress exciton–vibration coupling,thereby reducing the nonradiative decay rate.Moreover,introducing F atoms significantly decreases the reorganization energy for the S_(0)→S_(1) and S_(0)→cation transitions while increasing the reorganization energy for the S_(1)→S_(0) and cation→S_(0) transitions.These changes facilitate exciton dissociation and reduce the energy loss caused by dissociation and nonradiative recombination of excitons.Additionally,introducing F atoms into polymers enhances theπ–πstacking strength and the crystal coherence length in both neat and blended films,ultimately resulting in improvements in the power conversion efficiency of PBTA-PSF:L8-BO and PBDB-PSF:L8-BO are 16.51%and 17.59%,respectively.This study provides valuable insights for designing organic semiconductor materials to minimize energy loss and achieve a higher power conversion efficiency.展开更多
Traditional medicine,deeply rooted in cultural practices and historical wisdom,has faced surging challenges due to the escalating demand for plant-based remedies.This comprehensive review critically emphasizes the urg...Traditional medicine,deeply rooted in cultural practices and historical wisdom,has faced surging challenges due to the escalating demand for plant-based remedies.This comprehensive review critically emphasizes the urgent need for sustainable practices within traditional medicine,with a special focus on the potential of plant part substitution.Case studies that illuminate successful instances of substituting plant parts and providing a deep insight into viable alternatives to conventional practices are presented.Opportunities and challenges inherent in plant part substitution are discussed by addressing key considerations such as phytochemical and pharmacological aspects,safety and toxicity profiles,cultural insights,standardization,clinical validation,and regulatory compliance.This review serves as a guide for navigating the delicate balance between tradition and conservation within indigenous medicine practices.It underscores the importance of embracing sustainable approaches through plant part substitution,ensuring the preservation of cultural heritage while meeting the evolving healthcare needs of society.展开更多
Na_(2)FePO_(4)F is a promising sodium ion cathode due to its low cost,non-toxicity,and high stability.However,the sluggish Na^(+)diffusion kinetics and limited intrinsic electronic conductivity critically restrict its...Na_(2)FePO_(4)F is a promising sodium ion cathode due to its low cost,non-toxicity,and high stability.However,the sluggish Na^(+)diffusion kinetics and limited intrinsic electronic conductivity critically restrict its worldwide application.Herein,an anion-substitution strategy is proposed with SiO_(4)^(4-)as the dopant.SiO_(4)^(4-)substitution for PO_(4)^(3-)can apparently alter the localized electronic density and structural configuration in the lattice of Na_(2)FePO_(4)F,effectively elevating the charge transfer efficiency.As a result,the electrochemical reaction kinetics of Na_(2)FePO_(4)F is significantly enhanced,which is well demonstrated by a series of electrochemical characterizations.As-obtained Na_(2.2)Fe(PO_(4))_(0.8)(SiO_(4))_(0.2)F renders a specific capacity of 84.9 m A h g^(-1)within the region of 2.5-4.0 V at 60 mA g^(-1)(0.5 C),good rate capability,and a capacity retention of 70.0% after 1000 cycles at 1.24 A g^(-1)(10 C).Furthermore,the stabilities of the cathode-electrolyte interface and structure are strengthened,which are verified by in situ EIS and ex situ XRD analysis.These findings highlight silicate anion substitution as a promising and cost-effective strategy for overcoming the limitations of Na_(2)FePO_(4)F,contributing to the development of sustainable energy storage solutions.展开更多
P-stereogenic compounds play pivotal roles in natural products,pharmaceuticals,bioactive molecules,and catalysts/ligands,making their synthesis a highly researched area.Current studies have predominantly concentrated ...P-stereogenic compounds play pivotal roles in natural products,pharmaceuticals,bioactive molecules,and catalysts/ligands,making their synthesis a highly researched area.Current studies have predominantly concentrated on fully carbon-substituted P-stereogenic species,despite the fact that many therapeutically relevant compounds feature P-O,P-N,or P-S bonds.The catalytic and stereoselective nucleophilic substitution at the P-center is acknowledged as a highly efficient and straightforward approach for constructing high-value P-stereogenic compounds,offering significant potential for further development.This review provides an overview of advancements in the construction of P-stereogenic centers based on Pcentered nucleophilic substitution,highlighting key challenges,breakthroughs,and future opportunities in the field.展开更多
This work investigated the microstructure,magnetic properties,and crystallization kinetics of the as-spun and annealed alloy ribbons of(Fe_(40-x)Co_xNi_(40)Si_(6.33)B_(12.66)Cu_1)_(0.97)Nb_(0.03),where x=0,6,7,8,9,pre...This work investigated the microstructure,magnetic properties,and crystallization kinetics of the as-spun and annealed alloy ribbons of(Fe_(40-x)Co_xNi_(40)Si_(6.33)B_(12.66)Cu_1)_(0.97)Nb_(0.03),where x=0,6,7,8,9,prepared using the meltspinning method.The results show that adding a moderate amount of Co can improve the glass forming ability(GFA),the first peak crystallization temperature,and thermal stability of the as-spun alloy ribbons.With x=7,the two-stage crystallization temperature interval△Tx=90 exhibits optimal thermal stability,and the alloy annealed at 673 K for 10 minutes shows the favorable combined magnetic properties,with H_(c)=0.12 A/m,M_(s)=88.7 A·m^(2)/kg,andμ_(e)=13800.The magnetic domain results show that annealing removes numerous pinning points in the magnetic domains of the alloy ribbons,making the domain walls smoother and effectively reducing the pinning effect.展开更多
A structural conjugate(HOC)of polysaccharide,hyaluronic acid(HA)with different ratios of oleic acid(OA)via cystamine(CYS)linker as a new ocular biomaterial was developed.The HOCs with controlled degrees of substitutio...A structural conjugate(HOC)of polysaccharide,hyaluronic acid(HA)with different ratios of oleic acid(OA)via cystamine(CYS)linker as a new ocular biomaterial was developed.The HOCs with controlled degrees of substitution of OA(4.6%,8.3%and 12.2%)were synthesized to form self-assembled HA-CYS-OA nanoparticles(HONs,HON1,HON2,HON3).A poorly water-soluble cyclosporine A(CsA)to be used for the treatment of multifactorial dry eye disease(DED)was chosen as model drug.CsA-loaded HONs exhibited improved solution transparency via solubilizing capacity of HON,and increased in vitro drug permeation compared to Restasis®.The physicochemical properties of CsA-loaded HONs such as nano behaviors,solution transparency,drug release,drug permeation and ocular cytocompatibility were highly variable according to the ratios of OA substitution.Interestingly,this CsA-loaded HON1 as optimal ocular nanoformulation showed markedly augmentedmacrophage polarization into the M2 phenotype,downregulated the expression of proinflammatory cytokines levels in LPS-induced M1 macrophage,and effectively inhibited VEGF-induced endothelial cell proliferation and capillary-like tube formation by the synergistic effect of CsA and HON1 containing OA at the same time.Collectively,the current fatty acid conjugated to HA,named fattigation platform,providing the roles and physicochemical properties via structural features of HA could be a promising co-delivery strategy of drug and fatty acid for DED and other ophthalmic disease treatments.展开更多
Low ionic conductivity is a major obstacle for polymer solid-state electrolytes.In response to this issue,a design concept of enhanced regional electric potential difference(EREPD)is proposed to modulate the interacti...Low ionic conductivity is a major obstacle for polymer solid-state electrolytes.In response to this issue,a design concept of enhanced regional electric potential difference(EREPD)is proposed to modulate the interaction of nanofillers with other components in the composite polymer solid-state electrolytes(CPSEs).While ensuring the periodic structure of the graphdiyne(GDY)backbone,methoxysubstituted GDY(OGDY)is prepared by an asymmetric substitution strategy,which increases the electric potential differences within each repeating unit of GDY.The staggered distributed electron-rich regions and electron-deficient regions on the two-dimensional plane of OGDY increase the free Li^(+)concentration through Lewis acid-base pair interaction.The adjacent ERRs and EDRs form uniformly distributed EREPDs,creating a continuous potential gradient that synergistically facilitates the efficient migration of Li^(+).Impressively,the OGDY/poly(ethylene oxide)(PEO)exhibits a high ionic conductivity(1.1×10^(-3)S cm^(−1))and ion mobility number(0.71).In addition,the accelerated Li^(+)migration promotes the formation of uniform and dense SEI layers and inhibits the growth of lithium dendrites.As a proof of concept,Li||Li symmetric cell and Li||LiFePO_(4)full cell and pouch cell assembled with OGDY/PEO exhibit good performance,highlighting the effectiveness of our EREPD design strategy for improving CPSEs performance.展开更多
As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)poss...As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)possesses favorable electrochemical properties and thermodynamic stability,its intrinsic semiconductor characteristics result in a relatively slow electron transfer rate,limiting the ORR catalytic activity.In this work,the electronic structure of FeWO_(4)is significantly modulated by introducing phosphorus(P)atoms with abundant valence electrons.The P doping can adjust the electronic structure of FeWO_(4)and then optimize oxygen-containing intermediates'absorption/desorption efficiency to achieve improved ORR activity.Furthermore,the sodium chloride template is utilized to construct a porous carbon framework for anchoring phosphorus-doped iron tungstate(P-FeWO_(4)/PNC).The porous carbon skeleton provides numerous active sites for the absorption/desorption and redox reactions on the P-FeWO_(4)/PNC surface and serves as mass transport channels for reactants and intermediates.The P-FeWO_(4)/PNC demonstrates ORR performance(E1/2=0.86 V vs.RHE).Furthermore,the zinc-air batteries incorporating the P-FeWO_(4)/PNC composite demonstrate an increased peak power density(172.2 mW·cm^(-2)),high specific capacity(810.1 mAh·g^(-1)),and sustained long-term cycling stability lasting up to 240 h.This research not only contributes to the advancement of cost-effective tungsten-based non-precious metallic ORR catalysts,but also guides their utilization in zinc-air batteries.展开更多
Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemist...Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemistry of O3-type layered oxide cathode materials.This work systematically investigates the effect of Fe doping on the anionic oxygen redox chemistry and electrochemical reactions in O3-NaNi_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1)O_(2).The results of the density functional theory(DFT)calculations indicate that the electrons of the O 2p occupy a higher energy level.In the ex-situ X-ray photoelectron spectrometer(XPS)of O 1s,the addition of Fe facilitates the lattice oxygen(O^(n-))to exhibit enhanced activity at 4.45 V.The in-situ X-ray diffraction(XRD)demonstrates that the doping of Fe effectively suppresses the Y phase transition at high voltages.Furthermore,the Galvanostatic Intermittent Titration Technique(GITT)data indicate that Fe doping significantly increases the Na~+migration rate at high voltages.Consequently,the substitution of Fe can elevate the cut-off voltage to 4.45 V,thereby facilitating electron migration from O^(2-).The redox of O^(2-)/O^(n-)(n<2)contributes to the overall capacity.O3-Na(Ni_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1))_(0.92)Fe_(0.08)O_(2)provides an initial discharge specific capacity of 180.55 mA h g^(-1)and71.6%capacity retention at 0.5 C(1 C=240 mA g^(-1)).This work not only demonstrates the beneficial impact of Fe substitution for promoting the redox activity and reversibility of O^(2-)in 03-type layered oxides,but also guarantees the structural integrity of the cathode materials at high voltages(>4.2 V).It offers a novel avenue for investigating the anionic redox reaction in O3-type layered oxides to design advanced cathode materials.展开更多
A broad-spectrum UV photodetector with ultrahigh detectivity and rapid response speed has been achieved inβ-Ga_(2)O_(3)/GaN heterojunction,in which,theβ-Ga_(2)O_(3) is synthesized by substituting oxygen for nitrogen...A broad-spectrum UV photodetector with ultrahigh detectivity and rapid response speed has been achieved inβ-Ga_(2)O_(3)/GaN heterojunction,in which,theβ-Ga_(2)O_(3) is synthesized by substituting oxygen for nitrogen in the top layer of the GaN matrix at high temperature.The processes and mechanism of transforming GaN with varying crystal quality into β-Ga_(2)O_(3) at high temperatures were studied in detail.The newly formed oxide layer is a monoclinic β-Ga_(2)O_(3) with(01)preferred orientation.X-ray photoelectron spectroscopy(XPS)and atomic force microscope(AFM)measurements identified oxygen vacancies and surface flatness of β-Ga_(2)O_(3),respectively,which are closely related to the crystal quality of GaN.The oxygen vacancies and the root mean square of morphology roughness of β-Ga_(2)O_(3) decrease with the improvement of the precursor GaN crystal quality.The cross-section transmission electron microscope(TEM)measurements showed that a hexagonal phase GaN_(x)O_(3(1−x)/2)intermediate layer with a thickness of 5 nm exists at the interface region betweenβ-Ga_(2)O_(3) and hexagonal GaN.This indicates a molecular reconfiguration of the hexagonal system to a monoclinic system with oxygen substitution of nitrogen in GaN matrix.The metal-semiconductor-metal(MSM)planar structure device achieved an ultrahigh detection capability(Responsivity=2493.5 A/W,Detectivity>10^(16)Jones).The response time is in the order of milliseconds(τ_(r)=0.27 ms,τ_(d1)/τ_(d2)=0.33 ms/4.3 ms).A self-powered UV optoelectronic rapid response(τ_(r)=5µs,τ_(d1)/τ_(d2)=0.13 ms/2.3 ms)with the responsivity of 0.6 mA/W and the detectivity of 5.3×10^(11)Jones in the solar-blind wavelength region has been observed in the β-Ga_(2)O_(3)/GaN heterojunction without external bias.With a bias of−10 V loading,the response of the photodetector becomes a broad spectrum,covering the UVA-UVC wavelength range,and the photoresponsivity is up to 13.5 A/W.The detectivity reaches a high value of 2.6×10^(15)Jones.展开更多
Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of phot...Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of photoelectric devices.However,pristine Mn^(2+):CsPbCl_(3)NCs commonly suffer from low photoluminescence quantum yield(PL QY) and stability issues.Herein,we introduced europium ions(Eu^(3+))into Mn^(2+):CsPbCl_(3)NCs via the thermal injection synthesis method to obtain high performance Eu^(3+)and Mn^(2+)codoped CsPbCl_(3)(Eu^(3+)/Mn^(2+):CsPbCl_(3)) NCs.The maximum PL QY of the resulting Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs reaches up to 90.92%.It is found that the doping of Eu^(3+)ions significantly reduces the non-radiative recombination caused by high defect states,and improves the energy transfer efficiency from exciton to Mn^(2+),thereby boosting the PL performance.Moreover,doping Eu^(3+)ions notably improves the UV-light and water stability of Mn^(2+):CsPbCl_(3)NCs.We further demonstrate the application versatility of Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs in white light emitting diodes(WLEDs) and optical anticounterfeiting applications.This work provides a valuable perspective for the attainment of high performance Mn^(2+):CsPbCl_(3)NCs and lays a foundation for the codoping of other lanthanide ions to adjust the luminescence properties of Mn^(2+):CsPbCl_(3)NCs.展开更多
Due to their superior fluorescence,phosphorescence,and catalytic capabilities,carbon dots(CDs),an emerging class of fluorescent carbon nanomaterials,have a wide range of potential applications.The properties of CDs ha...Due to their superior fluorescence,phosphorescence,and catalytic capabilities,carbon dots(CDs),an emerging class of fluorescent carbon nanomaterials,have a wide range of potential applications.The properties of CDs have recently been controlled extensively by heteroatom doping.Boron atoms have been effectively doped into the structure of CDs due to their similar size to carbon atoms and excellent electron-absorbing ability to further improve the performance of CDs.In this review,we summarize the research progress of boron-doped CDs in recent years from the aspects of doping strategies,effects of boron doping on different performances of CDs and applications.Starting from the two aspects of single boron doping and boron and other atom co-doping,from different precursor materials to different synthesis methods,the doping strategies of boron-doped CDs are reviewed in detail.Then,the effects of boron doping on the fluorescence,phosphorescence and catalytic performance of CDs and applications of boron-doped CDs in optical sensors,information encryption and anti-counterfeiting are discussed.Finally,we further provide a prospect towards the future development of boron-doped CDs.展开更多
基金supported by the Guangxi Natural Science Foundation(Grant No.2025GXNSFDA069038)The Guangxi Science and Technology Plan Project(Grant No.AA23073018)+1 种基金the National Natural Science Foundation of China(Grant Nos.22175043 and 52162021)the Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures(Grant No.MMCS2023OF05).
文摘Rare-earth ion-doped garnets with excellent luminescent properties show great potential for temperature sensing,displays,and nondestructive detection.However,their limited luminescent modes and low photoluminescence quantum yields(PLQY)restrict further applications.In this study,we synthesized Al^(3+),Er^(3+)-co-doped Gd_(3)Ga_(5)O_(12) garnets with multimode luminescence via a high-temperature solid-state method.Notably,the preferential substitution of Al^(3+)ion at octahedral-coordinated GaI sites significantly enhanced the charge density and electron transition probability,achieving a PLQY enhancement of the downshifting luminescence from 35.1%to 68.5%.Al^(3+)ion also influences electron relaxation during up-conversion luminescence,resulting in a color shift from red to yellow to green.Additionally,Al^(3+)incorporation increased the photoelectric conversion efficiency of light-emitting diodes from 2.9%to 6.3%and improved temperature sensing sensitivity from 2.7%to 5.1%K⁻1.This work provides new insights into the photophysical mechanisms and underscores the key role of Al^(3+)ion in optimizing the optical properties of garnet-based materials.
文摘Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N catalysis.Monosubstitu-tion C—N bond formation reaction catalyzed by K_(2)CO_(3) also gave novel enol-based target products.This method is simple and mild,with good chemoselectivity,excellent substrate compatibility and tolerance for various functional groups,and achieves gram-scale synthesis.The reaction is a nucleophilic substitution process without the involvement of free radicals.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1402203)the National Natural Science Foundations of China(Grant Nos.12174065 and 12104424)the Shanghai Municipal Science and Technology(Grant No.2019SHZDZX01)。
文摘In this work,Ga-doped Ce RhIn_(5) single crystals are grown by In/Ga flux method.Single-crystal X-ray diffraction,magnetic susceptibility,specific heat,and neutron diffraction measurements are utilized to characterize the sample quality and the antiferromagnetic transition temperature T_(N).By substituting In with Ga,T_(N) is slightly decreased,but the antiferromagnetic transition peaks in magnetic susceptibility and specific heat measurements are obviously broadened by external field along c-axis.By comparing with Zn-doped Ce RhIn_(5),it can be concluded that T_(N) is dominated by electron density,and the stiffness of antiferromagnetic transition is obviously reduced by Ga substitution.The substitution effects of Ga are possibly caused by forming heterogeneous local structures,which avoids quantum critical point,superconductivity,and non-Fermi liquid states.Investigations on Gadoped Ce RhIn_(5) help to comprehend the chemical substitution effects in Ce RhIn_(5),and the interaction between heterogeneous structure and long-range antiferromagnetic states.
基金the Central Universities(Nos.SWU-KF25028 and SWU-XDJH202314)Natural Science Foundation Project of Chongqing(No.cstc2024ycjh-bgzxm0005)the Opening Project of State Key Laboratory of Solid Lubrication(No.LSL2416)for financial support.We also thank Analytical&Testing Center in Southwest University for SEM test.
文摘Perovskite barium titanate(BaTiO3)demonstrates exceptional dielectric properties as a promising microwave-absorbing(MA)material.Leveraging structural flexibility of perovskites,magnetic components can be incorporated at A/B-sites to enhance MA performance,yet the fundamental disparity in MA mechanisms between A/B-site magnetic doping remains elusive.Herein,nickel-doped BaTiO3 perovskites were systematically synthesized through precise adjustment of the Ba/Ti molar ratio to achieve both A-site(Ni_(x)Ba_(1−x)TiO_(3),N_(x)BTO)and B-site(BaTi_(1−x)Ni_(x)O_(3),BTN^(x)O)substitutions(0≤x≤0.1)via a simple one-step hydrothermal method.Notably,A-site Ni^(2+)substitution in N_(x)BTO induced superior magnetic loss(tanδμ=0.39)attributed to eddy-current dissipation,while B-site doping in BTN^(x)O achieved higher dielectric loss(tanδε=0.49).The N0.1BTO sample exhibited optimal MA performance with a remarkable minimum reflection loss(RLmin)of−44.39 dB and broad effective absorption bandwidth(EAB=8.66 GHz)covering the Ku-band and 67%X-band.Multimodal analysis revealed synergistic interactions among multiple reflection and scattering,multi-polarization relaxation,natural resonance,and eddy currents.In contrast,BTN0.01O demonstrated deeper RLmin(−50.88 dB)but narrower EAB(3.33 GHz)governed by dielectric mechanisms.Structural characterization indicated A-site doping induced lattice distortion,reduced unit-cell volume,and optimized oxygen vacancy distribution,synergistically balancing magneto-dielectric parameters.Conversely,B-site substitution increased oxygen vacancy concentration and carrier mobility while amplifying dielectric fluctuations.The spatial occupation preference of A/B dopants(A-site and B-site)governs lattice symmetry breaking,consequently establishing structure-property relationships and underpinning the material’s tunable dielectric behavior and magnetic phenomena.This work proposes a site-selective doping strategy for designing high-performance perovskite MA materials through magneto-dielectric equilibrium optimization.
文摘Metal oxides as support for constructing precious metal single-atom catalysts hold great promise for a wide range of industrial applications,but achieving a high-loading of thermally stable metal single atoms on such supports has been challenging.Herein,we report an innovative strategy for the fabrication of high-density single-atoms(Rh,Ru,Pd)catalysts on CaAl-layered double hydroxides(CaAl-LDH)via isomorphous substitution.The Rh species have occupied Ca^(2+)vacancies within CaAl-LDH laminate by ion-exchange,facilitating a substantial loading of isolated Rh single-atoms.Such catalysts displayed superior performance in the selective hydrogenation to quinoline,pivotal for liquid organic hydrogen storage,and the universality for the hydrogenation of N-heterocyclic aromatic hydrocarbons was also verified.Combining the experimental results and density functional theory calculations,the pathway of quinoline hydrogenation over Rh1CaAl-LDH was proposed.This synthetic strategy marks a significant advancement in the field of single-atom catalysts,expanding their horizons in green chemical processes.
基金supported by the National Natural Science Foundation of China(22275072 and 62105184)the Natural Science Foundation of Guangdong Province(2020A1515010622)+1 种基金the Project of Science and Technology of Guangzhou(2024A04J3712)the Teli Young Scholar Program of Beijing Institute of Technology.
文摘Donor-acceptor(D-A)compounds are particularly important in optoelectronic and biological applications.However,they are normally synthesized in the presence of transition metal catalysts.Herein,we report a metal-free method by a complexmediated nucleophilic aromatic substitution of aryl nitriles with amines.The method can lead to rich D-A type aggregation-induced emission luminogens(AIEgens)with tunable properties.They emit from deep-blue to yellow-green and possess high photoluminescence quantum yields up to 70.5%in the aggregate state.Interestingly,the suppression of intramolecular flapping is proved to play an indispensable role in the AIE behavior,which is different from the mechanism met in other AIEgens.Moreover,the biocompatible AIEgens possess specific staining of lipid droplets in HeLa cells and the superiority of identifying fatty liver over traditional Oil Red O staining is exhibited.
基金financially supported by the National Natural Science Foundation of China(No.52373011)。
文摘Living cationic polymerization of 4-acetoxystyrene(STO)was conducted in CH_(2)Cl_(2) at-15℃ using a dicumyl chloride(DCC)/SnCl_(4)/nBu_(4)NBr initiating system.Impurity moisture initiation was inhibited by adding proton trap 2,6-di-tert-butylpyridine(DTBP),and the controlled initiation of DCC was confirmed by ^(1)H nuclear magnetic resonance(^(1)H-NMR)spectroscopy and matrix-assisted laser desorption ionization time-offlight mass(MALDI-TOF-MS)spectrometry.The polymerization kinetics were analyzed to for optimizing the polymerization rate.Allyl-telechelic PSTOs(allyl-PSTO-allyl)with molecular weight(Mn)range of 3540–7800 g/mol and narrow molecular weight dispersity(Mw/Mn)about 1.25 were prepared through nucleophilic substitution with allyltrimethylsilane(ATMS)at approximately 40%monomer conversion.The experimental results indicate that the substitution efficiency of ATMS increased with higher ATMS concentration,temperature,and extended reaction time.Nearly unity ally-functionality for allyl-PSTO-allyl was achieved by adding sufficient SnCl_(4) prior to the substitution.
基金supported by the National Natural Science Foundation of China[Grant No.:32070438].
文摘Understanding the molecular relevance of metabolic rate(MR)is crucial for unveiling the mechanisms driving the evolution of animals.In this study,we investigated the association between mitochondrial DNA characteristics and both resting and maximal MRs in conjunction with life-history traits among 139 species of teleost fish,We gathered fish MR data from various sources and procured sequences of 13 mitochondrial protein-encoding genes.We calculated the absolute substitution rate for entire nucleotide sequences and 4-fold degenerate sites of each gene,along with encoding amino acid sequences.Using the phylogenetic comparative method,we then explored the associations between MR and mitochondrial DNA absolute substitution rate.Additionally,we screened MR-associated single nucleotide variants in mitochondrial DNA.The findings indicate no positive correlation between MRs and any substitution rate values of both combined sequences and individual mitochondrial protein-coding genes,refuting the MR hypothesis.Instead,both maximum body size and longevity correlated negatively with molecular substitution rates,suggesting their influences on both mutation and fixation within mitochondrial genes in fish.Results also revealed significant correlations between base variation at ATP6_169 and both resting MR and maximum MR,identifying the unique ATP6_169G in Scombridae fish,which results in an extremely low isoelectric point(pl)value of the ATP6 protein.Considering its functional significance,the ATP6_169G in Scombridae fish might link to their lifestyle characterized by fast locomotion and high metabolic demands alongside a slower molecular evolutionary rate.
基金supported by the National Natural Science Foundation of China(Grant No.62027822)the National R&D Program of China(Grant No.2019YFA0706402).
文摘Fluorine(F)substitution in polymers modulates both molecular energy levels and film morphology;however,its impact on exciton–vibrational coupling and molecular reorganization energy is often neglected.Herein,we systematically investigated F-modified polymers(PBTA-PSF,PBDB-PSF)and their nonfluorinated counterparts(PBTA-PS,PBDB-PS)through simulations and experiments.We found that F atoms effectively lower the vibrational frequency of the molecular skeleton and suppress exciton–vibration coupling,thereby reducing the nonradiative decay rate.Moreover,introducing F atoms significantly decreases the reorganization energy for the S_(0)→S_(1) and S_(0)→cation transitions while increasing the reorganization energy for the S_(1)→S_(0) and cation→S_(0) transitions.These changes facilitate exciton dissociation and reduce the energy loss caused by dissociation and nonradiative recombination of excitons.Additionally,introducing F atoms into polymers enhances theπ–πstacking strength and the crystal coherence length in both neat and blended films,ultimately resulting in improvements in the power conversion efficiency of PBTA-PSF:L8-BO and PBDB-PSF:L8-BO are 16.51%and 17.59%,respectively.This study provides valuable insights for designing organic semiconductor materials to minimize energy loss and achieve a higher power conversion efficiency.
文摘Traditional medicine,deeply rooted in cultural practices and historical wisdom,has faced surging challenges due to the escalating demand for plant-based remedies.This comprehensive review critically emphasizes the urgent need for sustainable practices within traditional medicine,with a special focus on the potential of plant part substitution.Case studies that illuminate successful instances of substituting plant parts and providing a deep insight into viable alternatives to conventional practices are presented.Opportunities and challenges inherent in plant part substitution are discussed by addressing key considerations such as phytochemical and pharmacological aspects,safety and toxicity profiles,cultural insights,standardization,clinical validation,and regulatory compliance.This review serves as a guide for navigating the delicate balance between tradition and conservation within indigenous medicine practices.It underscores the importance of embracing sustainable approaches through plant part substitution,ensuring the preservation of cultural heritage while meeting the evolving healthcare needs of society.
基金funding support from the Beijing Natural Science Foundation(2252055)the National Natural Science Foundation of China(52072033 and 52271234)+1 种基金the State Key Laboratory of Clean Energy Utilization(Open Fund Project,ZJUCEU2024010)the BIT Research and Innovation Promoting Project(2024YCXY040,GIIP2023-34)。
文摘Na_(2)FePO_(4)F is a promising sodium ion cathode due to its low cost,non-toxicity,and high stability.However,the sluggish Na^(+)diffusion kinetics and limited intrinsic electronic conductivity critically restrict its worldwide application.Herein,an anion-substitution strategy is proposed with SiO_(4)^(4-)as the dopant.SiO_(4)^(4-)substitution for PO_(4)^(3-)can apparently alter the localized electronic density and structural configuration in the lattice of Na_(2)FePO_(4)F,effectively elevating the charge transfer efficiency.As a result,the electrochemical reaction kinetics of Na_(2)FePO_(4)F is significantly enhanced,which is well demonstrated by a series of electrochemical characterizations.As-obtained Na_(2.2)Fe(PO_(4))_(0.8)(SiO_(4))_(0.2)F renders a specific capacity of 84.9 m A h g^(-1)within the region of 2.5-4.0 V at 60 mA g^(-1)(0.5 C),good rate capability,and a capacity retention of 70.0% after 1000 cycles at 1.24 A g^(-1)(10 C).Furthermore,the stabilities of the cathode-electrolyte interface and structure are strengthened,which are verified by in situ EIS and ex situ XRD analysis.These findings highlight silicate anion substitution as a promising and cost-effective strategy for overcoming the limitations of Na_(2)FePO_(4)F,contributing to the development of sustainable energy storage solutions.
基金financial support from the National Natural Science Foundation of China(Nos.22171187 and 22001173)the Project of Department of Education of Guangdong Province(No.2020KTSCX116)+3 种基金the Shenzhen Science and Technology Foundation(Nos.20200812202943001 and KQJSCX20180328100401788)Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules,Department of Education,Guizhou Province(No.Qianjiaohe KY(2020)004)the Central Government Guides Local Science and Technology Development Fund Projects(Nos.Qiankehezhongyindi(2024)007,(2023)001)Singapore National Research Foundation under its NRF Competitive Research Program(No.NRFCRP22–2019–0002)。
文摘P-stereogenic compounds play pivotal roles in natural products,pharmaceuticals,bioactive molecules,and catalysts/ligands,making their synthesis a highly researched area.Current studies have predominantly concentrated on fully carbon-substituted P-stereogenic species,despite the fact that many therapeutically relevant compounds feature P-O,P-N,or P-S bonds.The catalytic and stereoselective nucleophilic substitution at the P-center is acknowledged as a highly efficient and straightforward approach for constructing high-value P-stereogenic compounds,offering significant potential for further development.This review provides an overview of advancements in the construction of P-stereogenic centers based on Pcentered nucleophilic substitution,highlighting key challenges,breakthroughs,and future opportunities in the field.
基金Project supported by the National Natural Science Foundation of China(Grant No.52275567)the Key Research and Development Program of Shanxi Province,China(Grant No.202202050201020)+3 种基金the Doctoral Starting-up Foundation of Taiyuan University of Science and Technology(Grant No.20192016)the Research Project Supported by Shanxi Scholarship Council(Grant No.2017-085)the Graduate Education and Teaching Reform Project of Shanxi Province,China(Grant No.2023JG136)the Special Fund for Science and Technology Innovation Teams of Shanxi Province,China(Grant No.202304051001036)。
文摘This work investigated the microstructure,magnetic properties,and crystallization kinetics of the as-spun and annealed alloy ribbons of(Fe_(40-x)Co_xNi_(40)Si_(6.33)B_(12.66)Cu_1)_(0.97)Nb_(0.03),where x=0,6,7,8,9,prepared using the meltspinning method.The results show that adding a moderate amount of Co can improve the glass forming ability(GFA),the first peak crystallization temperature,and thermal stability of the as-spun alloy ribbons.With x=7,the two-stage crystallization temperature interval△Tx=90 exhibits optimal thermal stability,and the alloy annealed at 673 K for 10 minutes shows the favorable combined magnetic properties,with H_(c)=0.12 A/m,M_(s)=88.7 A·m^(2)/kg,andμ_(e)=13800.The magnetic domain results show that annealing removes numerous pinning points in the magnetic domains of the alloy ribbons,making the domain walls smoother and effectively reducing the pinning effect.
基金supported by a grant from the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(RS-2023-00208240),Republic of Korea.
文摘A structural conjugate(HOC)of polysaccharide,hyaluronic acid(HA)with different ratios of oleic acid(OA)via cystamine(CYS)linker as a new ocular biomaterial was developed.The HOCs with controlled degrees of substitution of OA(4.6%,8.3%and 12.2%)were synthesized to form self-assembled HA-CYS-OA nanoparticles(HONs,HON1,HON2,HON3).A poorly water-soluble cyclosporine A(CsA)to be used for the treatment of multifactorial dry eye disease(DED)was chosen as model drug.CsA-loaded HONs exhibited improved solution transparency via solubilizing capacity of HON,and increased in vitro drug permeation compared to Restasis®.The physicochemical properties of CsA-loaded HONs such as nano behaviors,solution transparency,drug release,drug permeation and ocular cytocompatibility were highly variable according to the ratios of OA substitution.Interestingly,this CsA-loaded HON1 as optimal ocular nanoformulation showed markedly augmentedmacrophage polarization into the M2 phenotype,downregulated the expression of proinflammatory cytokines levels in LPS-induced M1 macrophage,and effectively inhibited VEGF-induced endothelial cell proliferation and capillary-like tube formation by the synergistic effect of CsA and HON1 containing OA at the same time.Collectively,the current fatty acid conjugated to HA,named fattigation platform,providing the roles and physicochemical properties via structural features of HA could be a promising co-delivery strategy of drug and fatty acid for DED and other ophthalmic disease treatments.
基金supported by the National Key Research and Development Project of China(2022YFA1204500,2022YFA1204503,2018YFA0703501)the National Natural Science Foundation of China(22275115,21875274,11704024)+4 种基金the Natural Science Foundation of Shandong Province(ZR2024ZD02)Natural Science Foundation of Hebei Province(B2020201006)Hebei Province Innovation Capability Enhancement Plan Project(22567620H)Young Scholarship Funding of Shandong University.Post-graduate Innovation Fund Project of Open Laboratory Project Fund of Hebei University(HBU2025SS010)Basic Research Project of Shandong University-Xin’an Group Silicon-Based High-End New Materials Institute.
文摘Low ionic conductivity is a major obstacle for polymer solid-state electrolytes.In response to this issue,a design concept of enhanced regional electric potential difference(EREPD)is proposed to modulate the interaction of nanofillers with other components in the composite polymer solid-state electrolytes(CPSEs).While ensuring the periodic structure of the graphdiyne(GDY)backbone,methoxysubstituted GDY(OGDY)is prepared by an asymmetric substitution strategy,which increases the electric potential differences within each repeating unit of GDY.The staggered distributed electron-rich regions and electron-deficient regions on the two-dimensional plane of OGDY increase the free Li^(+)concentration through Lewis acid-base pair interaction.The adjacent ERRs and EDRs form uniformly distributed EREPDs,creating a continuous potential gradient that synergistically facilitates the efficient migration of Li^(+).Impressively,the OGDY/poly(ethylene oxide)(PEO)exhibits a high ionic conductivity(1.1×10^(-3)S cm^(−1))and ion mobility number(0.71).In addition,the accelerated Li^(+)migration promotes the formation of uniform and dense SEI layers and inhibits the growth of lithium dendrites.As a proof of concept,Li||Li symmetric cell and Li||LiFePO_(4)full cell and pouch cell assembled with OGDY/PEO exhibit good performance,highlighting the effectiveness of our EREPD design strategy for improving CPSEs performance.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22178148 and 22278193)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)possesses favorable electrochemical properties and thermodynamic stability,its intrinsic semiconductor characteristics result in a relatively slow electron transfer rate,limiting the ORR catalytic activity.In this work,the electronic structure of FeWO_(4)is significantly modulated by introducing phosphorus(P)atoms with abundant valence electrons.The P doping can adjust the electronic structure of FeWO_(4)and then optimize oxygen-containing intermediates'absorption/desorption efficiency to achieve improved ORR activity.Furthermore,the sodium chloride template is utilized to construct a porous carbon framework for anchoring phosphorus-doped iron tungstate(P-FeWO_(4)/PNC).The porous carbon skeleton provides numerous active sites for the absorption/desorption and redox reactions on the P-FeWO_(4)/PNC surface and serves as mass transport channels for reactants and intermediates.The P-FeWO_(4)/PNC demonstrates ORR performance(E1/2=0.86 V vs.RHE).Furthermore,the zinc-air batteries incorporating the P-FeWO_(4)/PNC composite demonstrate an increased peak power density(172.2 mW·cm^(-2)),high specific capacity(810.1 mAh·g^(-1)),and sustained long-term cycling stability lasting up to 240 h.This research not only contributes to the advancement of cost-effective tungsten-based non-precious metallic ORR catalysts,but also guides their utilization in zinc-air batteries.
基金financial support from the Natural Science Foundation of Shandong Province of China(ZR2023ME051,ZR2019MEM020)。
文摘Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemistry of O3-type layered oxide cathode materials.This work systematically investigates the effect of Fe doping on the anionic oxygen redox chemistry and electrochemical reactions in O3-NaNi_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1)O_(2).The results of the density functional theory(DFT)calculations indicate that the electrons of the O 2p occupy a higher energy level.In the ex-situ X-ray photoelectron spectrometer(XPS)of O 1s,the addition of Fe facilitates the lattice oxygen(O^(n-))to exhibit enhanced activity at 4.45 V.The in-situ X-ray diffraction(XRD)demonstrates that the doping of Fe effectively suppresses the Y phase transition at high voltages.Furthermore,the Galvanostatic Intermittent Titration Technique(GITT)data indicate that Fe doping significantly increases the Na~+migration rate at high voltages.Consequently,the substitution of Fe can elevate the cut-off voltage to 4.45 V,thereby facilitating electron migration from O^(2-).The redox of O^(2-)/O^(n-)(n<2)contributes to the overall capacity.O3-Na(Ni_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1))_(0.92)Fe_(0.08)O_(2)provides an initial discharge specific capacity of 180.55 mA h g^(-1)and71.6%capacity retention at 0.5 C(1 C=240 mA g^(-1)).This work not only demonstrates the beneficial impact of Fe substitution for promoting the redox activity and reversibility of O^(2-)in 03-type layered oxides,but also guarantees the structural integrity of the cathode materials at high voltages(>4.2 V).It offers a novel avenue for investigating the anionic redox reaction in O3-type layered oxides to design advanced cathode materials.
基金financially supported by National Key Technologies Research and Development Program of China(No.2019YFA0705202)National Natural Science Foundation of China(Nos.62274027,62404039)+3 种基金Open Research Fund of Songshan Lake Materials Laboratory(No.2023SLABFK03)Funding from Jilin Province(No.20220502002GH)Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(No.GZC20230416)Fundamental Research Funds for the Central Universities(No.2412024QD010).
文摘A broad-spectrum UV photodetector with ultrahigh detectivity and rapid response speed has been achieved inβ-Ga_(2)O_(3)/GaN heterojunction,in which,theβ-Ga_(2)O_(3) is synthesized by substituting oxygen for nitrogen in the top layer of the GaN matrix at high temperature.The processes and mechanism of transforming GaN with varying crystal quality into β-Ga_(2)O_(3) at high temperatures were studied in detail.The newly formed oxide layer is a monoclinic β-Ga_(2)O_(3) with(01)preferred orientation.X-ray photoelectron spectroscopy(XPS)and atomic force microscope(AFM)measurements identified oxygen vacancies and surface flatness of β-Ga_(2)O_(3),respectively,which are closely related to the crystal quality of GaN.The oxygen vacancies and the root mean square of morphology roughness of β-Ga_(2)O_(3) decrease with the improvement of the precursor GaN crystal quality.The cross-section transmission electron microscope(TEM)measurements showed that a hexagonal phase GaN_(x)O_(3(1−x)/2)intermediate layer with a thickness of 5 nm exists at the interface region betweenβ-Ga_(2)O_(3) and hexagonal GaN.This indicates a molecular reconfiguration of the hexagonal system to a monoclinic system with oxygen substitution of nitrogen in GaN matrix.The metal-semiconductor-metal(MSM)planar structure device achieved an ultrahigh detection capability(Responsivity=2493.5 A/W,Detectivity>10^(16)Jones).The response time is in the order of milliseconds(τ_(r)=0.27 ms,τ_(d1)/τ_(d2)=0.33 ms/4.3 ms).A self-powered UV optoelectronic rapid response(τ_(r)=5µs,τ_(d1)/τ_(d2)=0.13 ms/2.3 ms)with the responsivity of 0.6 mA/W and the detectivity of 5.3×10^(11)Jones in the solar-blind wavelength region has been observed in the β-Ga_(2)O_(3)/GaN heterojunction without external bias.With a bias of−10 V loading,the response of the photodetector becomes a broad spectrum,covering the UVA-UVC wavelength range,and the photoresponsivity is up to 13.5 A/W.The detectivity reaches a high value of 2.6×10^(15)Jones.
基金Project supported by the National Natural Science Foundation of China (12174075)the Scientific and Technological Bases and Talents of Guangxi (Guike AD21220016)+1 种基金Guangxi Science and Technology Major Project(AA23073018)the special fund for Guangxi Bagui Scholars。
文摘Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of photoelectric devices.However,pristine Mn^(2+):CsPbCl_(3)NCs commonly suffer from low photoluminescence quantum yield(PL QY) and stability issues.Herein,we introduced europium ions(Eu^(3+))into Mn^(2+):CsPbCl_(3)NCs via the thermal injection synthesis method to obtain high performance Eu^(3+)and Mn^(2+)codoped CsPbCl_(3)(Eu^(3+)/Mn^(2+):CsPbCl_(3)) NCs.The maximum PL QY of the resulting Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs reaches up to 90.92%.It is found that the doping of Eu^(3+)ions significantly reduces the non-radiative recombination caused by high defect states,and improves the energy transfer efficiency from exciton to Mn^(2+),thereby boosting the PL performance.Moreover,doping Eu^(3+)ions notably improves the UV-light and water stability of Mn^(2+):CsPbCl_(3)NCs.We further demonstrate the application versatility of Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs in white light emitting diodes(WLEDs) and optical anticounterfeiting applications.This work provides a valuable perspective for the attainment of high performance Mn^(2+):CsPbCl_(3)NCs and lays a foundation for the codoping of other lanthanide ions to adjust the luminescence properties of Mn^(2+):CsPbCl_(3)NCs.
基金the Youth Talent Program Startup Foundation of Qufu Normal University(No.602601)the Natural Science Foundation of Rizhao(No.RZ2021ZR37)。
文摘Due to their superior fluorescence,phosphorescence,and catalytic capabilities,carbon dots(CDs),an emerging class of fluorescent carbon nanomaterials,have a wide range of potential applications.The properties of CDs have recently been controlled extensively by heteroatom doping.Boron atoms have been effectively doped into the structure of CDs due to their similar size to carbon atoms and excellent electron-absorbing ability to further improve the performance of CDs.In this review,we summarize the research progress of boron-doped CDs in recent years from the aspects of doping strategies,effects of boron doping on different performances of CDs and applications.Starting from the two aspects of single boron doping and boron and other atom co-doping,from different precursor materials to different synthesis methods,the doping strategies of boron-doped CDs are reviewed in detail.Then,the effects of boron doping on the fluorescence,phosphorescence and catalytic performance of CDs and applications of boron-doped CDs in optical sensors,information encryption and anti-counterfeiting are discussed.Finally,we further provide a prospect towards the future development of boron-doped CDs.
