Prostate cancer(PCa)is characterized by high incidence and propensity for easy metastasis,presenting significant challenges in clinical diagnosis and treatment.Tumor microenvironment(TME)-responsive nanomaterials prov...Prostate cancer(PCa)is characterized by high incidence and propensity for easy metastasis,presenting significant challenges in clinical diagnosis and treatment.Tumor microenvironment(TME)-responsive nanomaterials provide a promising prospect for imaging-guided precision therapy.Considering that tumor-derived alkaline phosphatase(ALP)is over-expressed in metastatic PCa,it makes a great chance to develop a theranostics system with ALP responsive in the TME.Herein,an ALP-responsive aggregationinduced emission luminogens(AIEgens)nanoprobe AMNF self-assembly was designed for enhancing the diagnosis and treatment of metastatic PCa.The nanoprobe exhibited self-aggregation in the presence of ALP resulted in aggregation-induced fluorescence,and enhanced accumulation and prolonged retention period at the tumor site.In terms of detection,the fluorescence(FL)/computed tomography(CT)/magnetic resonance(MR)multi-mode imaging effect of nanoprobe was significantly improved post-aggregation,enabling precise diagnosis through the amalgamation of multiple imaging modes.Enhanced CT/MR imaging can achieve assist preoperative tumor diagnosis,and enhanced FL imaging technology can achieve“intraoperative visual navigation”,showing its potential application value in clinical tumor detection and surgical guidance.In terms of treatment,AMNF showed strong absorption in the near infrared region after aggregation,which improved the photothermal treatment effect.Overall,our work developed an effective aggregation-enhanced theranostic strategy for ALP-related cancers.展开更多
As commercial electron transport materials for perovskite solar cells(PSCs),pre-synthesized tin oxide(SnO_(2))nanoparticles suffer from colloidal agglomeration and inhomogeneous size distribution in aqueous solutions....As commercial electron transport materials for perovskite solar cells(PSCs),pre-synthesized tin oxide(SnO_(2))nanoparticles suffer from colloidal agglomeration and inhomogeneous size distribution in aqueous solutions.The formed micro-size SnO_(2)aggregates on the planar indium tin oxide(ITO)substrate not only create energy disorder to impair interfacial charge transfer but also hampers the growth of perovskite crystals,deteriorating the photovoltaic performance and device lifespan of PSCs.Here,a multidentate ligand of 1,2-cyclohexanedinitrilotetraacetic acid(CDTA)is developed to modify the surface chemistry of ITO substrates,facilitating the formation of pinhole-free and uniform SnO_(2)electron transport layers for the crystallization of high-quality perovskite films.Moreover,the surface CDTA ligands lift the work function of ITO from 4.68 to 4.12 eV,enabling interfacial band alignment modification to improve the electron extraction from the ITO/SnO_(2)interface.As a result,the CDTA-modified PSCs exhibit a significantly enhanced PCE of 24.67% and much prolonged device lifespan,retaining 91.3% and 92.8% of the initial PCEs under 2,000 h dark storage and after 500 h under one-sun illumination in nitrogen,respectively.This work demonstrates a simple yet efficient interfacial engineering strategy for the design of efficient and durable PSCs.展开更多
Gel-based sensors have provided unprecedented opportunities for bioelectric monitoring. Until now, sensors for underwater applicants have remained a notable challenge, as most sensors work effectively in air but swell...Gel-based sensors have provided unprecedented opportunities for bioelectric monitoring. Until now, sensors for underwater applicants have remained a notable challenge, as most sensors work effectively in air but swell underwater leading to functional failure. Herein, we introduce an innovative amphibian-inspired high-performance ionogel, where multiple supramolecular interactions in the ionogel's network confer good stretchability, elasticity, conductivity, and the hydrophobic C-F bonds play a key role in diminishing water molecule hydration and provide outstanding environmental stability. These unique properties of ionogels make them suitable as wearable amphibious fiexible sensors, and the sensors are capable of highly sensitive and stable human motion monitoring in air and underwater. Integration of the designed sensor into an artificial intelligence drowning alarm system, which recognizes the swimmer's movement status by monitoring the amplitude and frequency, especially in the drowning status for real-time alarms.This work provides novel strategies for motion recognition and hazard monitoring in amphibious environments, meeting the new generation of wearable sensors.展开更多
Zwitterionic materials with covalently tethered cations and anions have great potential as electrolyte additives for aqueous Znion batteries(AZIBs)owing to their appealing intrinsic characteristics and merits.However,...Zwitterionic materials with covalently tethered cations and anions have great potential as electrolyte additives for aqueous Znion batteries(AZIBs)owing to their appealing intrinsic characteristics and merits.However,the impact of cationic and anionic moieties within zwitterions on enhancing the performance of AZIBs remains poorly understood.Herein,three zwitterions,namely carboxybetaine methacrylate(CBMA),sulfobetaine methacrylate(SBMA),and 2-methacryloyloxyethyl phosphorylcholine(MPC),were selected as additives to investigate their different action mechanisms in AZIBs.All three zwitterions have the same quaternary ammonium as the positively charged group,but having different negatively charged segments,i.e.,carboxylate,sulfonate,and phosphate for CBMA,SBMA,and MPC,respectively.By systematical electrochemical analysis,these zwitterions all contribute to enhanced cycling life of Zn anode,with MPC having the most pronounced effect,which can be attributed to the synergistic effect of positively quaternary ammonium group and unique negatively phosphate groups.As a result,the Zn//Zn cell with MPC as additive in ZnSO_(4)electrolyte exhibits an ultralong lifespan over 5000 h.This work proposes new insights to the future development of multifunctional zwitterionic additives for remarkably stable AZIBs.展开更多
Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electroc...Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electrocatalysts with high SSA and optimized structure is of great significance but remains a tremendous challenge.Herein,we propose a general strategy for fabrication of mesoporous perovskite oxide nanosheets(MPONs)with controllable atomic doping via self-sacrificial template-induced nanostructure modulation.A variety of MPONs including LaFeO_(3),A-site-doped LaFeO_(3)(A-LaFeO_(3),where A is Pr,Nd,Sm,Eu,or Gd)and B-site-doped LaFeO_(3)(B-LaFeO_(3),where B is Mn,Co,Ni,Cu,or Zn)have been achieved.Interestingly,it is discovered that the catalytic activities of A-LaFeO_(3) MPONs as OER catalysts are overall higher than those of B-LaFeO_(3) ones.Especially,the screened Eu-LaFeO_(3) MPONs only require a low overpotential of 267 mV at 10 mA cm^(−2),outperforming most reported perovskite oxides.The superior catalytic activity of Eu-LaFeO_(3) MPONs is attributed to their favorable porous structure,which increases the density of active sites,and enhanced lattice oxygen participation,which improves the intrinsic activity.This study provides guidance for the design and controlled synthesis of advanced rare-earth-doped MPONs with ultrahigh SSA for enhanced electrocatalysis.展开更多
In this work,atomic Co catalysts are anchored on a three-dimensional(3D)interconnected g-C_(3)N_(4)(SACo-CN)through Co-N coordination,which exhibit efficient charge carrier transition and low activation energy barrier...In this work,atomic Co catalysts are anchored on a three-dimensional(3D)interconnected g-C_(3)N_(4)(SACo-CN)through Co-N coordination,which exhibit efficient charge carrier transition and low activation energy barriers for peroxymonosulfate(PMS).The incorporation of Co atoms extends the absorption spectrum and enhances the photoelectron-hole separation efficiency of the SACo-CN samples.The 3D interconnected structure,combined with the synergistic interplay between Co-N coordination and visible light irradiation,results in SACo-CN catalysts demonstrating excellent catalytic activity and stability for PMS activation.This leads to a degradation rate of 98.8%for oxytetracycline(OTC)within 30 min under visible light.The research proposes three potential mineralization pathways with eight intermediates,leading to a significant decrease in the toxicity of the intermediates.This work provides a facile and promising approach for the preparation of metal single atom catalysts with highly efficient PMS activation performance.展开更多
High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of...High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of phosphides.Herein,electrospinning and in situ phosphating were employed to prepare three-dimensional(3D)networks of self-supporting HEMP nanofibers with varying degrees of phosphate content.Comprehensive characterizations via X-ray diffraction and X-ray photoelectron spectroscopy,as well as density functional theory calculations,demonstrate that the introduction of phosphorus(P)atoms to HEMP carbon nanofibers mediates their electronic structure,leads to lattice expansion,which in turn enhances their catalytic performance in the hydrogen evolution reaction(HER).Moreover,the formation of metal-P bonds weakens metal-metal interaction and decreases the free energy of hydrogen adsorption,contributing to the exceptional activity observed in the HEMP catalyst.Electrochemical measurements demonstrate that the HEMP-0.75 catalyst with an ultralow loading of 1.22 wt%ruthenium(Ru)exhibits the highest HER catalytic activity and stability in a 1 M KOH electrolyte,achieving a minimal overpotential of 26 mV at a current density of 10 mA·cm^(-2)and Tafel slope of 50.9 mV·dec^(-1).展开更多
Photocatalysis has attracted much attention in recent years due to its potential in solving energy and environmental issues. Even though numerous achievements have been made, the photocatalytic systems developed to da...Photocatalysis has attracted much attention in recent years due to its potential in solving energy and environmental issues. Even though numerous achievements have been made, the photocatalytic systems developed to date are still far from practical applications due to the low efficiency and poor durability. Efficient light absorption and charge separation are two of the key factors for the exploration of high performance photocatalytic systems, which is generally difficult to be obtained in a single photocata- lyst. The combination of various materials to form heterojunctions provides an effective way to better harvest solar energy and to facilitate charge separation and transfer, thus enhancing the photocatalytic activity and stability. This review concisely summarizes the recent development of visible light respon- sive heterojunctions, including the preparation and performances of semiconductor/semiconductor junctions, semiconductor/cocatalyst junctions, semiconductor/metal junctions, semiconductor/non- metal junctions, and surface heterojunctions, and their mechanism for enhanced light harvesting and charge separation/transfer.展开更多
Photosynthetic microorganisms are important bioresources for producing desirable and environmentally benign products, and photobioreactors (PBRs) play important roles in these processes. Designing PBRs for photocataly...Photosynthetic microorganisms are important bioresources for producing desirable and environmentally benign products, and photobioreactors (PBRs) play important roles in these processes. Designing PBRs for photocatalysis is still challenging at present, and most reactors are designed and scaled up using semi- empirical approaches. No appropriate types of PBRs are available for mass cultivation due to the reactors' high capital and operating costs and short lifespan, which are mainly due to a current lack of deep understanding of the coupling of light, hydrodynamics, mass transfer, and cell growth in efficient reactor design. This review provides a critical overview of the key parameters that influence the performance of the PBRs, including light, mixing, mass transfer, temperature, pH, and capital and operating costs. The lifespan and the costs of cleaning and temperature control are also emphasized for commercial exploitation. Four types of PBRs-tubular, plastic bag, column airlift, and flat-panel airlift reactors are recommended for large- scale operations. In addition, this paper elaborates the modeling of PBRs using the tools of computational fluid dynamics for rational design. It also analyzes the difficulties in the numerical simulation, and presents the prospect for mechanism-based models.展开更多
Photocatalytic water splitting, which directly converts solar energy into hydrogen, is one of the most desirable solar-energy-conversion approaches. The ultimate target of photocatalysis is to explore efficient and st...Photocatalytic water splitting, which directly converts solar energy into hydrogen, is one of the most desirable solar-energy-conversion approaches. The ultimate target of photocatalysis is to explore efficient and stable photocatalysts for solar water splitting. Tantalum （oxy）nitride-based materials are a class of the most promising photocatalysts for solar water splitting because of their narrow bandgaps and sufficient band energy potentials for water splitting. Tantalum （oxy）nitride-based photocatalysts have experienced intensive exploration, and encouraging progress has been achieved over the past years. However, the solar- to-hydrogen （STH） conversion efficiency is still very far from its theoretical value. The question of how to better design these materials in order to further improve their water-splitting capability is of interest and importance. This review summarizes the development of tantalum （oxy）nitride-based photocatalysts for solar water spitting. Special interest is paid to important strategies for improving photocatalytic water- splitting efficiency. This paper also proposes future trends to explore in the research area of tantalum-based narrow bandgap photocatalysts for solar water splitting.展开更多
Photoelectrochemical(PEC)water splitting process is regarded as a promising route to generate hydrogen by solar energy and at the heart of PEC is efficient electrode design.Great progress has been achieved in the aspe...Photoelectrochemical(PEC)water splitting process is regarded as a promising route to generate hydrogen by solar energy and at the heart of PEC is efficient electrode design.Great progress has been achieved in the aspects of material design,cocatalyst study,and electrode fabrication over the past decades.However,some key challenges remain unsolved,including the most demanded conversion efficiency issue.As three critical steps,i.e.light harvesting,charge transfer and surface reaction of the PEC process,occur in a huge range of time scale(from10-12s to100s),how to manage these subsequent steps to facilitate the seamless cooperation between each step to realize efficient PEC process is essentially important.This review focuses on an integral consideration of the three key criteria based on the recent progress on high efficient and stable photoelectrode design in PEC.The basic principles and potential strategies are summarized.Moreover,the challenge and perspective are also discussed.展开更多
The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulati...The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulating their catalytic sites are a significant challenge in this field. Here,we propose an electrochemical surface restructuring strategy to design synergistically interactive phosphorus-doped carbon@MoP electrocatalysts for the HER. A simple electrochemical cycling method is developed to tune the thickness of the carbon layers that cover on MoP core,which significantly influences HER performance. Experimental investigations and theoretical calculations indicate that the inactive surface carbon layers can be removed through electrochemical cycling,leading to a close bond between the MoP and a few layers of coated graphene. The electronsdonated by the MoP core enhance the adhesion and electronegativity of the carbon layers;the negatively charged carbon layers act as an active surface. The electrochemically induced optimization of the surface/interface electronic structures in the electrocatalysts significantly promotes the HER. Using this strategy endows the catalyst with excellent activity in terms of the HER in both acidic and alkaline environments(current density of 10 mA cm^(-2) at low overpotentials,of 68 mV in 0.5 M H_(2)SO_(4) and 67 mV in 1.0 M KOH).展开更多
Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5...Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5×10^-30S cm^-1),associated lithium polysulfides(PSs),and their migration from the cathode to the anode.In this study,a separator coated with a Ketjen black(KB)/Nafion composite was used in an LSB with a sulfur loading up to 7.88 mg cm^-2to mitigate the PS migration.A minimum specific capacity(Cs)loss of 0.06%was obtained at 0.2 C-rate at a high sulfur loading of 4.39 mg cm^-2.Furthermore,an initial areal capacity up to 6.70 mAh cm^-2 was obtained at a sulfur loading of 7.88 mg cm^-2.The low Cs loss and high areal capacity associated with the high sulfur loading are attributed to the large surface area of the KB and sulfonate group(SO3^-)of Nafion,respectively,which could physically and chemically trap the PSs.展开更多
Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this...Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this work,two-dimensional(2D)ultrathin FePS3 nanosheets,a typical ternary metal phosphosulfide,are first prepared by ultrasonic exfoliation.The novel 2D/2D heterojunction of FePS3 nanosheets@MXene composite is then successfully synthesized by in situ mixing ultrathin MXene nanosheets with FePS3 nanosheets.The resultant FePS3 nanosheets@MXene hybrids can increase the electronic conductivity and specific surface area,assuring excellent surface and interfacial charge transfer abilities.Furthermore,the unique heterojunction endows FePS3 nanosheets@MXene composite to promote the diffusion of Na^+ and alleviate the drastic change in volume in the cyclic process,enhancing the sodium storage capability.Consequently,the few-layered FePS3 nanosheets uniformly coated by ultrathin MXene provide an exceptional reversible capacity of 676.1 mAh g^−1 at the current of 100 mA g^−1 after 90 cycles,which is equivalent to around 90.6% of the second-cycle capacity(746.4 mAh g^−1).This work provides an original protocol for constructing 2D/2D material and demonstrates the FePS3@MXene composite as a potential anode material with excellent property for sodium-ion batteries.展开更多
Due to the growing demand for clean and renewable hydrogen fuel,there has been a surge of interest in electrocatalytic water-splitting devices driven by renewable energy sources.However,the feasibility of self-driven ...Due to the growing demand for clean and renewable hydrogen fuel,there has been a surge of interest in electrocatalytic water-splitting devices driven by renewable energy sources.However,the feasibility of self-driven water splitting is limited by inefficient connections between functional modules,lack of highly active and stable electrocatalysts,and intermittent and unpredictable renewable energy supply.Herein,we construct a dualmodulated three-dimensional(3D)NiCo_(2)O_(4)@NiCo_(2)S_(4)(denoted as NCONCS)heterostructure deposited on nickel foam as a multifunctional electrode for electrocatalytic water splitting driven by photovoltaic-powered supercapacitors.Due to a stable 3D architecture configuration,abundant active sites,efficient charge transfer,and tuned interface properties,the NCONCS delivers a high specific capacity and rate performance for supercapacitors.A twoelectrode electrolyzer assembled with the NCONCS as both the anode and the cathode only requires a low cell voltage of 1.47 V to achieve a current density of 10 mA cm^(−2) in alkaline electrolyte,which outperforms the state-of-the-art bifunctional electrocatalysts.Theoretical calculations suggest that the generated heterointerfaces in NCONCS improve the surface binding capability of reaction intermediates while regulating the local electronic structures,which thus accelerates the reaction kinetics of water electrolysis.As a proof of concept,an integrated configuration comprising a two-electrode electrolyzer driven by two series-connected supercapacitors charged by a solar cell delivers a high product yield with superior durability.展开更多
Zinc–bromine rechargeable batteries(ZBRBs)are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost,deep discharge capability,non-flammable electrolytes,r...Zinc–bromine rechargeable batteries(ZBRBs)are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost,deep discharge capability,non-flammable electrolytes,relatively long lifetime and good reversibility.However,many opportunities remain to improve the efficiency and stability of these batteries for long-life operation.Here,we discuss the device configurations,working mechanisms and performance evaluation of ZBRBs.Both non-flow(static)and flow-type cells are highlighted in detail in this review.The fundamental electrochemical aspects,including the key challenges and promising solutions,are discussed,with particular attention paid to zinc and bromine half-cells,as their performance plays a critical role in determining the electrochemical performance of the battery system.The following sections examine the key performance metrics of ZBRBs and assessment methods using various ex situ and in situ/operando techniques.The review concludes with insights into future developments and prospects for high-performance ZBRBs.展开更多
Advanced cathode materials have been considered as the key to significantly improve the energy density of lithium-ion batteries(LIBs).High-Ni layer-structured cathodes,especially with Ni atomic content above 0.9(LiN1_...Advanced cathode materials have been considered as the key to significantly improve the energy density of lithium-ion batteries(LIBs).High-Ni layer-structured cathodes,especially with Ni atomic content above 0.9(LiN1_(x)M_(1-x)O_(2),x≥0.9),exhibit high capacity to be commercially available in electric vehicles(EVs).However,the intrinsic structure instability of high-Ni materials and the negative impacts severely restrict their further applic ation.In addition,Co has various effective efforts to stabilize the layered structure.Nevertheless,due to the high cost of Co,it is required to be replaced.Therefore,modification methods on increasing the stability of high-Ni cathode with the reduction of Co content have been widely investigated.In this review,we summarized various effective research progresses and several potential modification strategies of Cofree/Co-poor layered c athodes with Ni content over 0.9.The challenges and development opportunities of high-Ni,Cofree/Co-poor cathodes are further overviewed to meet the future commercial energy demands.展开更多
Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,...Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,their antibacterial efficacy is limited due to limited control in content and structure.Herein,we report a“dual active templating”strategy in the design of nanostructured silica composites with intrinsic antibacterial performance.This strategy uses cationic and anionic structural directing agents as dual templates,both with active antibacterial property.The cationic-anionic dual active templating strategy further contributes to antibacterial nanocomposites with a spiky surface.With controllable release of dual active antibacterial agents,the spiky nanocomposite displays enhanced anti-microbial and anti-biofilm properties toward Staphylococcus epidermidis.These findings pave a new avenue toward the designed synthesis of novel antibacterial nanocomposites with improved performance for diverse antibacterial applications.展开更多
We have studied the redox potentials and electronic properties of C60 and C59N using density functional theory method. It is found that doping C60 with one nitrogen atom results in a slight increase in redox potential...We have studied the redox potentials and electronic properties of C60 and C59N using density functional theory method. It is found that doping C60 with one nitrogen atom results in a slight increase in redox potential. Next, we have also studied C59N functionalized with various redox-active oxygen containing functional groups and strongly electron withdrawing functional groups. It is found that the intrinsic electronic structure of the molecule is the major determinant of the redox potential. Our DFT calculations show that the electron affinity to redox potential of functionalized C59N is correlated with the LUMO of the systems very well. This is the first systematic study on the redox properties and electronic structures of N-doped C60 systems.展开更多
Nitrogen-doped carbon materials as promising oxygen reduction reaction(ORR) electrocatalysts attract great interest in fuel cells and metal-air batteries because of their relatively high activity, high surface area, h...Nitrogen-doped carbon materials as promising oxygen reduction reaction(ORR) electrocatalysts attract great interest in fuel cells and metal-air batteries because of their relatively high activity, high surface area, high conductivity and low cost. To maximize their catalytic efficiency, rational design of efficient electrocatalysts with rich exposed active sites is highly desired. Besides, due to the complexity of nitrogen species, the identification of active nitrogen sites for ORR remains challenging. Herein, we develop a facile and scalable template method to construct high-concentration nitrogen-doped carbon hollow frameworks(NC), and reveal the effect of different nitrogen species on theirORRactivity on basis of experimental analysis and theoretical calculations. The formation mechanism is clearly revealed, including low-pressure vapor superassembly of thin zeolitic imidazolate framework(ZIF-8) shell on ZnO templates,in situ carbonization and template removal. The obtained NC-800 displays better ORR activity compared with other NC-700 and NC-900 samples. Our results indicate that the superior ORR activity of NC-800 is mainly attributed to its content balance of three nitrogen species. The graphitic N and pyrrolic N sites are responsible for lowering the working function, while the pyridinic N and pyrrolic N sites as possible active sites are beneficial for increasing the density of states.展开更多
基金supported by Natural Science Foundation of Jilin Province(No.SKL202302002)Key Research and Development project of Jilin Provincial Science and Technology Department(No.20210204142YY)+2 种基金The Science and Technology Development Program of Jilin Province(No.2020122256JC)Beijing Kechuang Medical Development Foundation Fund of China(No.KC2023-JX-0186BQ079)Talent Reserve Program(TRP),the First Hospital of Jilin University(No.JDYY-TRP-2024007)。
文摘Prostate cancer(PCa)is characterized by high incidence and propensity for easy metastasis,presenting significant challenges in clinical diagnosis and treatment.Tumor microenvironment(TME)-responsive nanomaterials provide a promising prospect for imaging-guided precision therapy.Considering that tumor-derived alkaline phosphatase(ALP)is over-expressed in metastatic PCa,it makes a great chance to develop a theranostics system with ALP responsive in the TME.Herein,an ALP-responsive aggregationinduced emission luminogens(AIEgens)nanoprobe AMNF self-assembly was designed for enhancing the diagnosis and treatment of metastatic PCa.The nanoprobe exhibited self-aggregation in the presence of ALP resulted in aggregation-induced fluorescence,and enhanced accumulation and prolonged retention period at the tumor site.In terms of detection,the fluorescence(FL)/computed tomography(CT)/magnetic resonance(MR)multi-mode imaging effect of nanoprobe was significantly improved post-aggregation,enabling precise diagnosis through the amalgamation of multiple imaging modes.Enhanced CT/MR imaging can achieve assist preoperative tumor diagnosis,and enhanced FL imaging technology can achieve“intraoperative visual navigation”,showing its potential application value in clinical tumor detection and surgical guidance.In terms of treatment,AMNF showed strong absorption in the near infrared region after aggregation,which improved the photothermal treatment effect.Overall,our work developed an effective aggregation-enhanced theranostic strategy for ALP-related cancers.
基金the financial support from the Fundamental Research Funds for the Central Universities and material characterizations from the Analytical&Testing Center of Northwestern Polytechnical Universitythe funding support from the Australian Research Council(ARC)Discovery Early Career Researcher Award。
文摘As commercial electron transport materials for perovskite solar cells(PSCs),pre-synthesized tin oxide(SnO_(2))nanoparticles suffer from colloidal agglomeration and inhomogeneous size distribution in aqueous solutions.The formed micro-size SnO_(2)aggregates on the planar indium tin oxide(ITO)substrate not only create energy disorder to impair interfacial charge transfer but also hampers the growth of perovskite crystals,deteriorating the photovoltaic performance and device lifespan of PSCs.Here,a multidentate ligand of 1,2-cyclohexanedinitrilotetraacetic acid(CDTA)is developed to modify the surface chemistry of ITO substrates,facilitating the formation of pinhole-free and uniform SnO_(2)electron transport layers for the crystallization of high-quality perovskite films.Moreover,the surface CDTA ligands lift the work function of ITO from 4.68 to 4.12 eV,enabling interfacial band alignment modification to improve the electron extraction from the ITO/SnO_(2)interface.As a result,the CDTA-modified PSCs exhibit a significantly enhanced PCE of 24.67% and much prolonged device lifespan,retaining 91.3% and 92.8% of the initial PCEs under 2,000 h dark storage and after 500 h under one-sun illumination in nitrogen,respectively.This work demonstrates a simple yet efficient interfacial engineering strategy for the design of efficient and durable PSCs.
基金supported by Natural Science Foundation of Jilin Province (No. SKL202302002)Key Research and Development Project of the Jilin Provincial Science and Technology Department (No. 20210204142YY)。
文摘Gel-based sensors have provided unprecedented opportunities for bioelectric monitoring. Until now, sensors for underwater applicants have remained a notable challenge, as most sensors work effectively in air but swell underwater leading to functional failure. Herein, we introduce an innovative amphibian-inspired high-performance ionogel, where multiple supramolecular interactions in the ionogel's network confer good stretchability, elasticity, conductivity, and the hydrophobic C-F bonds play a key role in diminishing water molecule hydration and provide outstanding environmental stability. These unique properties of ionogels make them suitable as wearable amphibious fiexible sensors, and the sensors are capable of highly sensitive and stable human motion monitoring in air and underwater. Integration of the designed sensor into an artificial intelligence drowning alarm system, which recognizes the swimmer's movement status by monitoring the amplitude and frequency, especially in the drowning status for real-time alarms.This work provides novel strategies for motion recognition and hazard monitoring in amphibious environments, meeting the new generation of wearable sensors.
基金supported by the Australian Research Council(LP220100036)the National Key Research and Development Program(2022YFB2502104 and 2022YFA1602700)+3 种基金the Key Research and Development Program of Jiangsu Provincial Department of Science and Technology of China(BE2022332)the Jiangsu Carbon Peak Carbon Neutralization Science and Technology Innovation Special Fund(BE2022605)the Australian Research Council for his Discovery Early Career Researcher Award fellowship(DE230101105)the China Scholarship Council(CSC,grant no.202306190185)for funding a scholarship。
文摘Zwitterionic materials with covalently tethered cations and anions have great potential as electrolyte additives for aqueous Znion batteries(AZIBs)owing to their appealing intrinsic characteristics and merits.However,the impact of cationic and anionic moieties within zwitterions on enhancing the performance of AZIBs remains poorly understood.Herein,three zwitterions,namely carboxybetaine methacrylate(CBMA),sulfobetaine methacrylate(SBMA),and 2-methacryloyloxyethyl phosphorylcholine(MPC),were selected as additives to investigate their different action mechanisms in AZIBs.All three zwitterions have the same quaternary ammonium as the positively charged group,but having different negatively charged segments,i.e.,carboxylate,sulfonate,and phosphate for CBMA,SBMA,and MPC,respectively.By systematical electrochemical analysis,these zwitterions all contribute to enhanced cycling life of Zn anode,with MPC having the most pronounced effect,which can be attributed to the synergistic effect of positively quaternary ammonium group and unique negatively phosphate groups.As a result,the Zn//Zn cell with MPC as additive in ZnSO_(4)electrolyte exhibits an ultralong lifespan over 5000 h.This work proposes new insights to the future development of multifunctional zwitterionic additives for remarkably stable AZIBs.
基金financially supported by the National Key Research and Development Program(Nos.2022YFB2502104 and 2022YFA1602700)the Key Research and Development Program of Jiangsu Provincial Department of Science and Technology of China(No.BE2022332)+4 种基金the Jiangsu Carbon Peak Carbon Neutralization Science and Technology Innovation Special Fund(No.BE2022605)the National Natural Science Foundation of China(Nos.22109073,22379071)the DECRA program of Australian Research Council(No.DE230100357)the JSPS KAKENHI(No.JP23K13703)the Center for Computational Materials Science,Institute for Materials Research,Tohoku University for the use of MASAMUNE-IMR(202312-SCKXX-0203)。
文摘Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electrocatalysts with high SSA and optimized structure is of great significance but remains a tremendous challenge.Herein,we propose a general strategy for fabrication of mesoporous perovskite oxide nanosheets(MPONs)with controllable atomic doping via self-sacrificial template-induced nanostructure modulation.A variety of MPONs including LaFeO_(3),A-site-doped LaFeO_(3)(A-LaFeO_(3),where A is Pr,Nd,Sm,Eu,or Gd)and B-site-doped LaFeO_(3)(B-LaFeO_(3),where B is Mn,Co,Ni,Cu,or Zn)have been achieved.Interestingly,it is discovered that the catalytic activities of A-LaFeO_(3) MPONs as OER catalysts are overall higher than those of B-LaFeO_(3) ones.Especially,the screened Eu-LaFeO_(3) MPONs only require a low overpotential of 267 mV at 10 mA cm^(−2),outperforming most reported perovskite oxides.The superior catalytic activity of Eu-LaFeO_(3) MPONs is attributed to their favorable porous structure,which increases the density of active sites,and enhanced lattice oxygen participation,which improves the intrinsic activity.This study provides guidance for the design and controlled synthesis of advanced rare-earth-doped MPONs with ultrahigh SSA for enhanced electrocatalysis.
基金financial support from the National Natural Science Foundation of China(Nos.22276159,J2224005)the Key research project plan for higher education institutions of Henan province(No.24ZX009)+1 种基金the Development Program for Key Young Teachers in Colleges and Universities of Henan Province(No.2020GGJS146)the Starting Research Fund of Xinxiang Medical University(No.XYBSKYZZ201911)。
文摘In this work,atomic Co catalysts are anchored on a three-dimensional(3D)interconnected g-C_(3)N_(4)(SACo-CN)through Co-N coordination,which exhibit efficient charge carrier transition and low activation energy barriers for peroxymonosulfate(PMS).The incorporation of Co atoms extends the absorption spectrum and enhances the photoelectron-hole separation efficiency of the SACo-CN samples.The 3D interconnected structure,combined with the synergistic interplay between Co-N coordination and visible light irradiation,results in SACo-CN catalysts demonstrating excellent catalytic activity and stability for PMS activation.This leads to a degradation rate of 98.8%for oxytetracycline(OTC)within 30 min under visible light.The research proposes three potential mineralization pathways with eight intermediates,leading to a significant decrease in the toxicity of the intermediates.This work provides a facile and promising approach for the preparation of metal single atom catalysts with highly efficient PMS activation performance.
基金supported by the National Natural Science Foundation of China(Nos.22103045 and 52273077)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZDKT202108,RZ2000003334 and G2RC202022)support from the Australian National Fabrication Facility’s Queensland Node(No.ANFF-Q),the UQ-Yonsei International Research Project,and the JST-ERATO Yamauchi Materials Space-Tectonics Project(No.JPMJER2003).
文摘High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of phosphides.Herein,electrospinning and in situ phosphating were employed to prepare three-dimensional(3D)networks of self-supporting HEMP nanofibers with varying degrees of phosphate content.Comprehensive characterizations via X-ray diffraction and X-ray photoelectron spectroscopy,as well as density functional theory calculations,demonstrate that the introduction of phosphorus(P)atoms to HEMP carbon nanofibers mediates their electronic structure,leads to lattice expansion,which in turn enhances their catalytic performance in the hydrogen evolution reaction(HER).Moreover,the formation of metal-P bonds weakens metal-metal interaction and decreases the free energy of hydrogen adsorption,contributing to the exceptional activity observed in the HEMP catalyst.Electrochemical measurements demonstrate that the HEMP-0.75 catalyst with an ultralow loading of 1.22 wt%ruthenium(Ru)exhibits the highest HER catalytic activity and stability in a 1 M KOH electrolyte,achieving a minimal overpotential of 26 mV at a current density of 10 mA·cm^(-2)and Tafel slope of 50.9 mV·dec^(-1).
基金the financial support from Australian Research Council through its DP and FF programsthe support from IPRS and UQ Centennial Scholarships
文摘Photocatalysis has attracted much attention in recent years due to its potential in solving energy and environmental issues. Even though numerous achievements have been made, the photocatalytic systems developed to date are still far from practical applications due to the low efficiency and poor durability. Efficient light absorption and charge separation are two of the key factors for the exploration of high performance photocatalytic systems, which is generally difficult to be obtained in a single photocata- lyst. The combination of various materials to form heterojunctions provides an effective way to better harvest solar energy and to facilitate charge separation and transfer, thus enhancing the photocatalytic activity and stability. This review concisely summarizes the recent development of visible light respon- sive heterojunctions, including the preparation and performances of semiconductor/semiconductor junctions, semiconductor/cocatalyst junctions, semiconductor/metal junctions, semiconductor/non- metal junctions, and surface heterojunctions, and their mechanism for enhanced light harvesting and charge separation/transfer.
基金This work was supported by the National Key Research and De- velopment Program of China (2016YFB0301701) the National Nat- ural Science Foundation of China (91434114, 21376254)+2 种基金 the Major National Scientific Instrument Development Project (21427814) the Instrument Developing Project of the Chinese Academy of Sciences (YZ201641) the International Partnership Program for Creative Re-search Teams, Chinese Academy of Sciences, and the Supercomput- ing Center of USTC (University of Science and Technology of China).
文摘Photosynthetic microorganisms are important bioresources for producing desirable and environmentally benign products, and photobioreactors (PBRs) play important roles in these processes. Designing PBRs for photocatalysis is still challenging at present, and most reactors are designed and scaled up using semi- empirical approaches. No appropriate types of PBRs are available for mass cultivation due to the reactors' high capital and operating costs and short lifespan, which are mainly due to a current lack of deep understanding of the coupling of light, hydrodynamics, mass transfer, and cell growth in efficient reactor design. This review provides a critical overview of the key parameters that influence the performance of the PBRs, including light, mixing, mass transfer, temperature, pH, and capital and operating costs. The lifespan and the costs of cleaning and temperature control are also emphasized for commercial exploitation. Four types of PBRs-tubular, plastic bag, column airlift, and flat-panel airlift reactors are recommended for large- scale operations. In addition, this paper elaborates the modeling of PBRs using the tools of computational fluid dynamics for rational design. It also analyzes the difficulties in the numerical simulation, and presents the prospect for mechanism-based models.
基金The authors would like to acknowledge financial support from the Australian Research Council through its DP and FF programs. Mu Xiao acknowledges support from the Australian Government Research Training Program Scholarship. Financial support from the National Natural Science Foundation of China （513228201） is also highly appreciated.
文摘Photocatalytic water splitting, which directly converts solar energy into hydrogen, is one of the most desirable solar-energy-conversion approaches. The ultimate target of photocatalysis is to explore efficient and stable photocatalysts for solar water splitting. Tantalum （oxy）nitride-based materials are a class of the most promising photocatalysts for solar water splitting because of their narrow bandgaps and sufficient band energy potentials for water splitting. Tantalum （oxy）nitride-based photocatalysts have experienced intensive exploration, and encouraging progress has been achieved over the past years. However, the solar- to-hydrogen （STH） conversion efficiency is still very far from its theoretical value. The question of how to better design these materials in order to further improve their water-splitting capability is of interest and importance. This review summarizes the development of tantalum （oxy）nitride-based photocatalysts for solar water spitting. Special interest is paid to important strategies for improving photocatalytic water- splitting efficiency. This paper also proposes future trends to explore in the research area of tantalum-based narrow bandgap photocatalysts for solar water splitting.
文摘Photoelectrochemical(PEC)water splitting process is regarded as a promising route to generate hydrogen by solar energy and at the heart of PEC is efficient electrode design.Great progress has been achieved in the aspects of material design,cocatalyst study,and electrode fabrication over the past decades.However,some key challenges remain unsolved,including the most demanded conversion efficiency issue.As three critical steps,i.e.light harvesting,charge transfer and surface reaction of the PEC process,occur in a huge range of time scale(from10-12s to100s),how to manage these subsequent steps to facilitate the seamless cooperation between each step to realize efficient PEC process is essentially important.This review focuses on an integral consideration of the three key criteria based on the recent progress on high efficient and stable photoelectrode design in PEC.The basic principles and potential strategies are summarized.Moreover,the challenge and perspective are also discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 21975286 and 21473254)the Special Project Fund of “Taishan Scholar” of Shandong Province (Grant No. ts201511017)+2 种基金the QLUT Special Funding for Distinguished Scholars (Grant No. 2419010420)the project ZR2020QE058 supported by Shandong Provincial Natural Science Foundationthe Fundamental Research Funds for the Central Universities (Grant Nos. YCX2020050,18CX06030A,and 17CX02039A)。
文摘The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulating their catalytic sites are a significant challenge in this field. Here,we propose an electrochemical surface restructuring strategy to design synergistically interactive phosphorus-doped carbon@MoP electrocatalysts for the HER. A simple electrochemical cycling method is developed to tune the thickness of the carbon layers that cover on MoP core,which significantly influences HER performance. Experimental investigations and theoretical calculations indicate that the inactive surface carbon layers can be removed through electrochemical cycling,leading to a close bond between the MoP and a few layers of coated graphene. The electronsdonated by the MoP core enhance the adhesion and electronegativity of the carbon layers;the negatively charged carbon layers act as an active surface. The electrochemically induced optimization of the surface/interface electronic structures in the electrocatalysts significantly promotes the HER. Using this strategy endows the catalyst with excellent activity in terms of the HER in both acidic and alkaline environments(current density of 10 mA cm^(-2) at low overpotentials,of 68 mV in 0.5 M H_(2)SO_(4) and 67 mV in 1.0 M KOH).
基金the Australian Government and University of Queensland for the research training program scholarship and research facilities used in this study.
文摘Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5×10^-30S cm^-1),associated lithium polysulfides(PSs),and their migration from the cathode to the anode.In this study,a separator coated with a Ketjen black(KB)/Nafion composite was used in an LSB with a sulfur loading up to 7.88 mg cm^-2to mitigate the PS migration.A minimum specific capacity(Cs)loss of 0.06%was obtained at 0.2 C-rate at a high sulfur loading of 4.39 mg cm^-2.Furthermore,an initial areal capacity up to 6.70 mAh cm^-2 was obtained at a sulfur loading of 7.88 mg cm^-2.The low Cs loss and high areal capacity associated with the high sulfur loading are attributed to the large surface area of the KB and sulfonate group(SO3^-)of Nafion,respectively,which could physically and chemically trap the PSs.
基金support funding is from the National Natural Science Foundation of China(51871119 and 51901100)China Jiangsu Specially Appointed Professor,Jiangsu Provincial Founds for Natural Science Foundation(BK20170793 and BK20180015)+2 种基金China Postdoctoral Science Foundation(2018M640481 and 2019T120426)Jiangsu Postdoctoral Research Fund(2019K003 and 2019K201)Jiangsu-Innovate UK Business Competition(BZ2017061)
文摘Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this work,two-dimensional(2D)ultrathin FePS3 nanosheets,a typical ternary metal phosphosulfide,are first prepared by ultrasonic exfoliation.The novel 2D/2D heterojunction of FePS3 nanosheets@MXene composite is then successfully synthesized by in situ mixing ultrathin MXene nanosheets with FePS3 nanosheets.The resultant FePS3 nanosheets@MXene hybrids can increase the electronic conductivity and specific surface area,assuring excellent surface and interfacial charge transfer abilities.Furthermore,the unique heterojunction endows FePS3 nanosheets@MXene composite to promote the diffusion of Na^+ and alleviate the drastic change in volume in the cyclic process,enhancing the sodium storage capability.Consequently,the few-layered FePS3 nanosheets uniformly coated by ultrathin MXene provide an exceptional reversible capacity of 676.1 mAh g^−1 at the current of 100 mA g^−1 after 90 cycles,which is equivalent to around 90.6% of the second-cycle capacity(746.4 mAh g^−1).This work provides an original protocol for constructing 2D/2D material and demonstrates the FePS3@MXene composite as a potential anode material with excellent property for sodium-ion batteries.
文摘Due to the growing demand for clean and renewable hydrogen fuel,there has been a surge of interest in electrocatalytic water-splitting devices driven by renewable energy sources.However,the feasibility of self-driven water splitting is limited by inefficient connections between functional modules,lack of highly active and stable electrocatalysts,and intermittent and unpredictable renewable energy supply.Herein,we construct a dualmodulated three-dimensional(3D)NiCo_(2)O_(4)@NiCo_(2)S_(4)(denoted as NCONCS)heterostructure deposited on nickel foam as a multifunctional electrode for electrocatalytic water splitting driven by photovoltaic-powered supercapacitors.Due to a stable 3D architecture configuration,abundant active sites,efficient charge transfer,and tuned interface properties,the NCONCS delivers a high specific capacity and rate performance for supercapacitors.A twoelectrode electrolyzer assembled with the NCONCS as both the anode and the cathode only requires a low cell voltage of 1.47 V to achieve a current density of 10 mA cm^(−2) in alkaline electrolyte,which outperforms the state-of-the-art bifunctional electrocatalysts.Theoretical calculations suggest that the generated heterointerfaces in NCONCS improve the surface binding capability of reaction intermediates while regulating the local electronic structures,which thus accelerates the reaction kinetics of water electrolysis.As a proof of concept,an integrated configuration comprising a two-electrode electrolyzer driven by two series-connected supercapacitors charged by a solar cell delivers a high product yield with superior durability.
基金flnancial support from Australian Research Council through its Discovery,Future Fellowship ProgramsImam Mohammad Ibn Saud Islamic University (IMSIU) in Riyadh,Saudi Arabia,for flnancial support of this work.
文摘Zinc–bromine rechargeable batteries(ZBRBs)are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost,deep discharge capability,non-flammable electrolytes,relatively long lifetime and good reversibility.However,many opportunities remain to improve the efficiency and stability of these batteries for long-life operation.Here,we discuss the device configurations,working mechanisms and performance evaluation of ZBRBs.Both non-flow(static)and flow-type cells are highlighted in detail in this review.The fundamental electrochemical aspects,including the key challenges and promising solutions,are discussed,with particular attention paid to zinc and bromine half-cells,as their performance plays a critical role in determining the electrochemical performance of the battery system.The following sections examine the key performance metrics of ZBRBs and assessment methods using various ex situ and in situ/operando techniques.The review concludes with insights into future developments and prospects for high-performance ZBRBs.
基金financially supported by the National Natural Science Foundation of China(Nos.22109091 and 91963113)。
文摘Advanced cathode materials have been considered as the key to significantly improve the energy density of lithium-ion batteries(LIBs).High-Ni layer-structured cathodes,especially with Ni atomic content above 0.9(LiN1_(x)M_(1-x)O_(2),x≥0.9),exhibit high capacity to be commercially available in electric vehicles(EVs).However,the intrinsic structure instability of high-Ni materials and the negative impacts severely restrict their further applic ation.In addition,Co has various effective efforts to stabilize the layered structure.Nevertheless,due to the high cost of Co,it is required to be replaced.Therefore,modification methods on increasing the stability of high-Ni cathode with the reduction of Co content have been widely investigated.In this review,we summarized various effective research progresses and several potential modification strategies of Cofree/Co-poor layered c athodes with Ni content over 0.9.The challenges and development opportunities of high-Ni,Cofree/Co-poor cathodes are further overviewed to meet the future commercial energy demands.
基金Open access funding provided by Shanghai Jiao Tong University
文摘Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,their antibacterial efficacy is limited due to limited control in content and structure.Herein,we report a“dual active templating”strategy in the design of nanostructured silica composites with intrinsic antibacterial performance.This strategy uses cationic and anionic structural directing agents as dual templates,both with active antibacterial property.The cationic-anionic dual active templating strategy further contributes to antibacterial nanocomposites with a spiky surface.With controllable release of dual active antibacterial agents,the spiky nanocomposite displays enhanced anti-microbial and anti-biofilm properties toward Staphylococcus epidermidis.These findings pave a new avenue toward the designed synthesis of novel antibacterial nanocomposites with improved performance for diverse antibacterial applications.
文摘We have studied the redox potentials and electronic properties of C60 and C59N using density functional theory method. It is found that doping C60 with one nitrogen atom results in a slight increase in redox potential. Next, we have also studied C59N functionalized with various redox-active oxygen containing functional groups and strongly electron withdrawing functional groups. It is found that the intrinsic electronic structure of the molecule is the major determinant of the redox potential. Our DFT calculations show that the electron affinity to redox potential of functionalized C59N is correlated with the LUMO of the systems very well. This is the first systematic study on the redox properties and electronic structures of N-doped C60 systems.
基金supported by the National Natural Science Foundation of China (51832004 and 51521001)the National Key Research and Development Program of China (2016YFA0202603)+2 种基金the Natural Science Foundation of Hubei Province (2019CFA001)the Programme of Introducing Talents of Discipline to Universities (B17034)the Yellow Crane Talent (Science & Technology) Program of Wuhan City。
文摘Nitrogen-doped carbon materials as promising oxygen reduction reaction(ORR) electrocatalysts attract great interest in fuel cells and metal-air batteries because of their relatively high activity, high surface area, high conductivity and low cost. To maximize their catalytic efficiency, rational design of efficient electrocatalysts with rich exposed active sites is highly desired. Besides, due to the complexity of nitrogen species, the identification of active nitrogen sites for ORR remains challenging. Herein, we develop a facile and scalable template method to construct high-concentration nitrogen-doped carbon hollow frameworks(NC), and reveal the effect of different nitrogen species on theirORRactivity on basis of experimental analysis and theoretical calculations. The formation mechanism is clearly revealed, including low-pressure vapor superassembly of thin zeolitic imidazolate framework(ZIF-8) shell on ZnO templates,in situ carbonization and template removal. The obtained NC-800 displays better ORR activity compared with other NC-700 and NC-900 samples. Our results indicate that the superior ORR activity of NC-800 is mainly attributed to its content balance of three nitrogen species. The graphitic N and pyrrolic N sites are responsible for lowering the working function, while the pyridinic N and pyrrolic N sites as possible active sites are beneficial for increasing the density of states.
