查看更多>>摘要：Potassium-ion hybrid capacitors(PIHCs)are widely regarded as highly promising energy storage devi-ces,due to their exceptional energy density,impressive power density,and abundant potassium resources.Unfor-tunately,restricted by the inherent capacitive storage mechanism,the carbon cathodes possess a much lower specific capacity than battery-type anodes.Therefore,designing high-performance carbon cathodes is extremely urgent for the development of PIHCs.Herein,N,O co-doped porous carbon(NOPC)was fabricated through the NaCl hard template method and combined KOH/melamine chemical activation technique,displaying the characteris-tics of abundant N/O content(4.7 at％/16.9 at％),ultrahigh specific surface area(3092 m2·g-1)and hierarchical pore network.The designed NOPC cathode delivers a high specific capacity(164.4 mAh·g-1 at 0.05 A·g-1)and superior cyclability(95.1％retention ratio at 2 A·g-1 over 2500 cycles).Notably,the adjustable ratio of micropores to mesopores facilitates the achievement of the optimal bal-ance between capacity and rate capability.Moreover,the pseudocapacitance can be further augmented through the incorporation of N/O functional groups.As expected,the graphite//NOPC based PIHC possesses a high energy density of 113Wh·kg-1 at 747 W·kg-1 and excellent capacity retention of 84.4％after 4000 cycles at 1.0 A·g-1.This work introduces a novel strategy for designing carbon cathodes that enhances the electrochemical performance of PIHCs.
查看更多>>摘要：Cobalt selenide(CoSe2)has garnered consid-erable attention as a prospective anode candidate for advanced lithium-ion storage,prompting comprehensive investigations.However,CoSe2-based anodes usually suf-fer from significant volume variation upon lithiation,leading to unsatisfactory cycling stability.Herein,a ver-satile synthesis route is proposed for the in-situ fabrication of CoSe2 nanoparticles embedded in N-dope carbon skeleton(CoSe2@NC)through annealing treatment and selenization of a metal-organic framework-derived(MOF)precursor.The N-doped carbon derived from the MOF serves not only as an excellent conductive substrate but also as a confined reactor,effectively inhibiting the struc-tural instability and alleviating the inevitable volume change of CoSe2.Owing to their unique nanostructure,the as-prepared CoSe2@NC exhibits a high capacity of 745.9 mAh·g-1 at 0.1 A·g-1,while maintaining excellent rate capability and an impressive lifespan.Furthermore,the assembled lithium-ion capacitor(LIC)based on CoSe2@NC demonstrates an energy density of 130 Wh·kg-1,a power density of 24.6 kW.kg-1,and remark-able capacity retention of 90.8％after 8000 cycles.These results highlight the great potential of CoSe2@NC for practical applications.
查看更多>>摘要：Efficient extraction of electrode components from recycled lithium-ion batteries(LIBs)and their high-value applications are critical for the sustainable and eco-friendly utilization of resources.This work demonstrates a novel approach to stripping graphite anodes embedded with Li+from spent LIBs directly in anhydrous ethanol,which can be utilized as high efficiency cathodes for alu-minum-ion batteries(AIBs).Recycled graphite(RG)with foam morphology and crystal structure defects was obtained under the action of ultrasonic peeling and gas generation reaction between residual lithium-graphite interlayer compound and ethanol.The inherent open structure of RG facilitates the intercalation/deintercalation of chloralum anions(AlCl4-)and enhances its AIB cathode performance.The electrochemical measurements reveal that the RG cathode has a specific capacity of 123 mAh·g-1 at a current of 5 A·g-1,which is 1.55 times higher than that of unprocessed natural graphite and 1.25 times higher than that of commercial artificial graphite.Additionally,the RG cathode demonstrated remarkable stability,retaining its high particular capacity of 138.15 mAh·g-1 even through 2000 times at 10 A·g-1 in a low-cost electrolyte consisting of an ionic liquid/urea/AlCl3 mixture.This work offers a novel approach to reusing of graphite anode waste mate-rials from LIBs.
查看更多>>摘要：Polarization upconversion luminescence(PUCL)of lanthanide ions(Ln3+)has been widely used in single particle tracking,microfluidics detection,three-di-mensional displays,and so on.However,no effective strategy has been developed for modulating PUCL.Here,we report a strategy to regulate PUCL in Ho3+-doped NaYF4 single nanorods based on the number of upcon-version photons.By constructing a multiphoton upcon-version system for Ho3+,we regulate the degree of polarization(DOP)of PUCL from 0.590 for two-photon luminescence to 0.929 for three-photon upconversion luminescence(UCL).Furthermore,our strategy is verified from cross-relaxation between Ho3+and Yb3+,excitation wavelength,excitation power density,and local site sym-metry.And this regulation strategy of PUCL has also been achieved in Tm3+,with the DOP ranging from 0.233 for two-photon luminescence to 0.925 for four-photon UCL.Besides,multi-dimensional anti-counterfeiting display has been explored with PUCL.This work provides an effective strategy for regulating PUCL and also provides more opportunities for the development of polarization display,optical encoding,anti-counterfeiting,and integrated optical devices.
查看更多>>摘要：Given the increasing number of diabetic patients,rapid and accurate detection of glucose in body fluids is critical.This study developed a direct electro-chemical biosensor for glucose based on nitrogen-doped carbon nanocages(NCNCs).NCNCs possess a large specific surface area of 1395 m2·g-1,a high N atomic content of 9.37％and good biocompatibility,which is favorable for enzyme loading and electron transfer.The surface average concentration of electroactive glucose oxidase on NCNCs was 2.82 × 10-10 mol·cm-2.The NCNC-based direct electrochemical biosensor exhibited a high sensitivity of 13.7 μA·(mmol·L-1)-1·cm-2,rapid response time of 5 s and an impressive electron-transfer-rate constant(ks)of 1.87 s-1.Furthermore,we investigated an NCNC-based direct electron transfer(DET)biosensor for sweat glucose detection,which demonstrated tremen-dous promise for non-invasive wearable diabetes diagnosis.
查看更多>>摘要：Methanol is one of the characteristic gases that distinguish between healthy individuals and lung cancer(LC)lesions in exhaled human breath.Its concentration in exhaled breath is generally below one part per million(1× 10-6).The second-phase composite is widely regarded as one of the methods to improve the gas-sensing perfor-mance of metal oxide semiconductor(MOS)materials.In this study,LaF3-Co3O4 was synthesized by a simple hydrothermal method to enhance its low-concentration methanol gas-sensing performance.5 at％LaF3-Co3O4 nanorods exhibited excellent methanol detection perfor-mance,including a wider linear detection concentration range(0.2 × 10-6-5× 10-6),a response value exceeding 4.0 for 1 × 10-6 methanol at 275 ℃ and 75％relative humidity(RH),long-term stability(maximum deviation within 15％over 2 weeks),and excellent selectivity.The mechanism of performance enhancement was studied using various techniques,and density functional theory.The special spinel structure of Co3O4,the high ionic migration of F-in LaF3,the larger specific surface area of 5 at％LaF3-Co3O4 nanorods,and the generated crystal defects all explain the excellent methanol gas-sensing property.This work provides a novel route to prepare MOS composite materials for low-concentration methanol gas detection.
查看更多>>摘要：Selective oxidation of alkanes to produce high-value chemicals is an essential strategy and means to realize efficient utilization of resources.In this work,a strategy of lanthanum manganese mixed metal oxides(LMMO)regulated via a facile ionic liquid(IL)-assisted hydrothermal method was proposed to construct the mul-tifunctional catalysts,which exhibited excellent catalytic performance in the selective aerobic oxidation of cyclo-hexane.An 8.9％cyclohexane conversion with 90％KA oil(cyclohexanol and cyclohexanone)selectivity was achieved over the optimal LMMO catalyst under mild conditions.The effects of anion type,carbon chain length and concentration of ILs on the structure and properties of catalysts were investigated through various characteriza-tions,indicating the structure-directing and template effect of ILs on the multifunctional catalysts.The formation of self-assembled spherical nanoparticles followed the"dis-solution-nucleation-proliferation"mechanism with the introduction of 1-butyl-3-methylimidazolium hydrogen sulfate,ascribing the synergistic effect between the microenvironment of ILs and the hydrothermal environ-ment.Importantly,the high reactive oxygen concentration,redox capacity,and suitable basic sites of LMMO catalysts mediated by ILs enhance the activation of C-H bonds and molecular oxygen,simultaneously influencing the adsorp-tion and desorption of the substrate.A comprehensive understanding of the high KA oil selectivity and radical reaction mechanism was elucidated based on in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and radical trapping experiments.The recycling and regeneration experiments further illuminated that the removal of adsorbed cyclohexanone acting on the LMMO catalyst was the key to achieve high KA oil selectivity.
查看更多>>摘要：CsPbBr3 inorganic perovskites have been regarded as the promising materials in the field of photo-voltaics because of the high tolerance against environment.The high energy barrier of phase transition from lead bromide(PbBr2)to CsPbBr3 perovskite and low solubility of perovskite in organic solvent impede the further improvement of device performance in terms of CsPbBr3 solar cells.Herein,an intermediate phase-assisted growth of CsPbBr3 perovskite was proposed by introducing tetraphenylphosphonium bromide(TPPB)as additive.The TPPB is expected to react with PbBr2 in organic solvent to form an intermediate phase of[TPPB·DMF]·PbBr2,which not only effectively improves the crystallinity of PbBr2 crystals,but also greatly reduces the phase transition energy barrier,leading to uniform and compact CsPbBr3 perovskite films with large grain size and high crystallinity.In combination with carbon electrode,the CsPbBr3 solar cells yield a champion device performance of 9.57％in comparison of pristine CsPbBr3 solar cells showing a low efficiency of 8.17％.Furthermore,the intermediate phase-assisted growth of CsPbBr3-based solar cells displays an outstanding storage over 720 h.
查看更多>>摘要：Although chemotherapy has been intensively applied in cancer treatments,its inadequate therapeutic efficacy and severe side effects are still under constant concerns.Nanoplatforms used as anti-tumor drug delivery system(DDS)have attracted tremendous attentions owing to their various intriguing properties.Herein,Mn-doped MoO2 nanoparticles coated with ZrO2 and capped with Bi2O3 have been designed as a DDS,namely MMZB.MMZB possesses good magnetic properties,great pho-tothermal conversion ability,sensitive tumor microenvi-ronment(TME)responsiveness,and good biocompatibility in hemocompatibility in vitro.Thus,MMZB has been utilized to load the chemotherapeutic agent daunomycin(DNM)(MMZB@DNM)for chemo-photothermal com-bined therapy.MMZB@DNM demonstrates a more impressive anti-cancer effect than the individual pho-tothermal or chemotherapy both in vitro and in vivo.Fur-thermore,the analysis of tumor specimen sections and serum levels after the treatment indicates negligible side effects for MMZB@DNM in vivo.This contribution pro-vides a valuable concept in designing therapeutic agents for achieving significantly enhanced tumor treatments,which benefits from the synergistic combination of chemotherapy and photothermal therapy in one single nanoagent.
查看更多>>摘要：An inorganic-organic hybrid crystalline mate-rial(SiMo12O40)[Cu(2,2'-bipy)2]2·2H2O(Complex 1,2,2'-bipy=2,2'-bipyridine)was synthesized for the first time by using 2,2'-bipy and transition metal copper to convert Waugh-type polyoxometalate[MnMo9O32]6-into a Keg-gin polyoxometalate structure[SiMo12O40]4-under hydrothermal conditions in glass vials.Single crystal tests and a series of characterizations were carried out on Complex 1.The structure of Complex 1 is composed of[SiMo12O40]4-and[CuⅡ(2,2'-bipy)2]2+.The five-coordi-nated Cu is connected to two 2,2'-bipy through Cu-N bonds,forming an approximately square structure.Aston-ishingly,Complex 1 exhibited good photocatalytic performance for methylene blue degradation and electro-catalytic nitrite reduction properties simultaneously.
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