The high-energy-density and low-cost features endow lithium-sulfur batteries with broad application prospects.However,many drawbacks,especially the detrimental shuttle effect,have hindered the further development of L...The high-energy-density and low-cost features endow lithium-sulfur batteries with broad application prospects.However,many drawbacks,especially the detrimental shuttle effect,have hindered the further development of LSBs.In response,a lot of new structures have been applied to suppress the shuttle effect and promote the development of LSBs.Recently,vacancy engineering has gained the attention of researchers due to its unique electronic structure.This review aims to analyze the application of vacancy engineering in LSBs.Firstly,the electrochemistry of LSBs has been systematically discussed and the existing challenges as well as improvement tactics of LSBs have also been presented.Subsequently,the preparation methods and characterization technologies of various vacancies are summarized,including oxygen vacancies,sulfur vacancies,selenium vacancies,other anion vacancies,cation vacancies,etc.The latest applications of vacancy engineering in LSBs are also summarized in this review.Finally,some prospects and insights for further investigation and practical application of vacancy engineering in LSBs are put forward.展开更多
Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme hetero...Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme heterojunction with O and Zn vacancies(VO,Zn-ZnO/ZnS)is rationally constructed via ion-exchange and calcination treatments.In such a photocatalytic system,the hollow structure combined with the introduction of dual vacancies endows the adequate light absorption.Moreover,the O and Zn vacancies serve as the trapping sites for photo-induced electrons and holes,respectively,which are beneficial for promoting the photo-induced carrier separation.Meanwhile,the S-scheme charge transfer mechanism can not only improve the separation and transfer efficiencies of photo-induced carrier but also retain the strong redox capacity.As expected,the optimized VO,Zn-ZnO/ZnS heterojunction exhibits a superior photocatalytic H_(2) production rate of 160.91 mmol g^(-1)h^(-1),approximately 643.6 times and 214.5 times with respect to that obtained on pure ZnO and ZnS,respectively.Simultaneously,the experimental results and density functional theory calculations disclose that the photo-induced carrier transfer pathway follows the S-scheme heterojunction mechanism and the introduction of O and Zn vacancies reduces the surface reaction barrier.This work provides an innovative strategy of vacancy engineering in S-scheme heterojunction for solar-to-fuel energy conversion.展开更多
The artificial nitrogen(N_(2)) reduction reaction(NRR) via electrocatalysis is a newly developed methodology to produce ammonia(NH3) at ambient conditions,but faces the challenges in N_(2)activation and poor reaction ...The artificial nitrogen(N_(2)) reduction reaction(NRR) via electrocatalysis is a newly developed methodology to produce ammonia(NH3) at ambient conditions,but faces the challenges in N_(2)activation and poor reaction selectivity.Herein,Nb-based MXenes are developed to remarkably enhance the NRR activity through the engineering of the stretched 3D structure and oxygen vacancies(VO).The theoretical studies indicate that N_(2)could be initially adsorbed on VOwith an end-on configuration,and the potential determining step might be the first hydrogenation step.The catalysts achieve an NH3production rate of 29.1 μg h^(-1)mg_(cat)^(-1)and excellent Faradic efficiency of 11.5%,surpassing other Nbbased catalysts.The selectivity of NRR is assigned to the unique structure of the catalysts,including(1) the layered graphitic structure for fast electron transfer and active site distribution,(2) the reactive VOfor N_(2)adsorption and activation,and(3) the expanded interlayer space for mass transfer.展开更多
Electrocatalysis plays an increasingly important role in converting atmospheric molecules(e.g.,N_(2),CO_(2) and H_(2)O)to value-added products(e.g.,NH_(3),C_(2)H_(4)and H_(2)).However,developing a simple strategy for ...Electrocatalysis plays an increasingly important role in converting atmospheric molecules(e.g.,N_(2),CO_(2) and H_(2)O)to value-added products(e.g.,NH_(3),C_(2)H_(4)and H_(2)).However,developing a simple strategy for preparing catalysts with high performance for the effective conversion of clean energy is still full of chal-lenges.Herein,we describe a straightforward,one-step reduction method to achieve the formation of Pt nanoparticles(NPs)and the vacancy engineering of TiO_(2-x)nanofibers(NFs)simultaneously,which can be accomplished in 5 min.Furthermore,a Pt/TiO_(2-x)nanofibrous aerogel(NA)with an ordered cellular archi-tecture is prepared through a directional freezing technology.The Pt/TiO_(2-x)NA with excellent mechanical properties can be made into a self-supporting electrode for electrocatalytic N_(2)reduction reaction(NRR),showing high NH_(3) yield rate(4.81×10^(-10)mol/s cm^(-2))and Faraday efficiency(14.9%)at-0.35 V vs.RHE.展开更多
Electron transport layer(ETL)is pivotal to charge carrier transport for PSCs to reach the Shockley-Queisser limit.This study provides a fundamental understanding of heterojunction electron transport layers(ETLs)at the...Electron transport layer(ETL)is pivotal to charge carrier transport for PSCs to reach the Shockley-Queisser limit.This study provides a fundamental understanding of heterojunction electron transport layers(ETLs)at the atomic level for stable and efficient perovskite solar cells(PSCs).The bilayer structure of an ETL composed of SnO_(2) on TiO_(2) was examined,revealing a critical factor limiting its potential to obtain efficient performance.Alteration of oxygen vacancies in the TiO_(2) underlayer via an annealing process is found to induce manipulated band offsets at the interface between the TiO_(2) and SnO_(2) layers.In-depth electronic investigations of the bilayer structure elucidate the importance of the electronic properties at the interface between the TiO_(2) and SnO_(2) layers.The apparent correlation in hysteresis phenomena,including current density-voltage(J-V)curves,appears as a function of the type of band alignment.Density functional theory calculations reveal the intimate relationship between oxygen vacancies,deep trap states,and charge transport efficiency at the interface between the TiO_(2) and SnO_(2) layers.The formation of cascade band alignment via control over the TiO_(2) underlayer enhances device performance and suppresses hysteresis.Optimal performance exhibits a power conversion efficiency(PCE)of 23.45%with an open-circuit voltage(V_(oc))of 1.184 V,showing better device stability under maximum power point tracking compared with a staggered bilayer under one-sun continuous illumination.展开更多
Among the many strategies for CO_(2)resource utilization,the synthetic technology of cyclic carbonates with 100%atom economy through CO_(2)and epoxide is one of the most industrially viable routes,but its efficiency h...Among the many strategies for CO_(2)resource utilization,the synthetic technology of cyclic carbonates with 100%atom economy through CO_(2)and epoxide is one of the most industrially viable routes,but its efficiency has been severely hampered by the lack of highly active catalytic sites.Moreover,due to the intrinsic thermodynamic stability and kinetic inertia of CO_(2)and the higher energy barrier of the ring-opening reaction of epoxides,the heterogeneous catalytic conversion of CO_(2)highly depends on harsh operating conditions,high temperatures and pressures,and the incorporation of cocatalysts.The devel-opment of efficient heterogeneous catalysts for CO_(2)conversion under cocatalyst-free and mild conditions has always been a challenge.Herein,we have proposed a synergetic strategy of facet and vacancy engi-neering for the construction of highly efficient heterogeneous catalyst BiO1-x Br1-y-(010)for CO_(2)cycload-dition,where introducing the OVs-BrVs pairs into typical(010)facets BiOBr with simultaneous surface Lewis acid sites Bi^(3+)and nucleophilic sites Br^(−).By combining theoretical calculations and a series of systematic experiments,such as CO_(2)temperature-programmed desorption,electron paramagnetic res-onance and fluorescence probe analysis experiments,the introduced OVs-BrVs pair can not only form Bi^(3+)-Bi^(3-x)+dual active sites on the surface,which activate PO and CO_(2)respectively to reduce the energy barrier of CO_(2)insertion,but also activate Br^(−)near BrVs to enhance their nucleophilic attacking ability and reduce the energy barrier of epoxides ring-opening.As a result,the BiO1-x Br1-y-(010)with abundant surface OVs-BrVs pairs showed a high cyclic carbonates conversion of 99%with 100%selectivity un-der cocatalyst-free and mild conditions,far surpassing most heterogeneous catalytic systems.This work provides a completely new strategy to construct high-performance heterogeneous CO_(2)cycloaddition cata-lysts through a simple facet and vacancy engineering strategy to overcome the harsh operating conditions limitation and the use of cocatalysts.展开更多
In contrast to alkaline water electrolysis,acidic water electrolysis remains an elusive goal due to the lack of earth-abundant,efficient,and acid-stable water oxidation electrocatalysts.Here,we show that materials wit...In contrast to alkaline water electrolysis,acidic water electrolysis remains an elusive goal due to the lack of earth-abundant,efficient,and acid-stable water oxidation electrocatalysts.Here,we show that materials with intrinsically poor electrocatalytic activity can be turned into active electrocatalysts that drive the acidic oxygen evolution reaction(OER)effectively.This development is achieved through ultrafast plasma sputtering,which introduces abundant oxygen vacancies that reconstruct the surface electronic structures,and thus,regulated the surface interactions of electrocatalysts and the OER intermediates.Using tungsten oxide(WO_(3))as an example,we present a broad spectrum of theoretical and experimental characterizations that show an improved energetics of OER originating from surface oxygen vacancies and resulting in a significantly boosted OER performance,compared with pristine WO_(3).Our result suggests the efficacy of using defect chemistry to modify electronic properties and hence to improve the OER performance of known materials with poor activity,providing a new direction for the discovery of acid-stable OER catalysts.展开更多
Developing efficient pH-universal hydrogen evolution reaction(HER)catalysts is critical in the field of water electrolysis,however,which is severely hampered by the sluggish kinetics in alkaline media.Herein,a rutheni...Developing efficient pH-universal hydrogen evolution reaction(HER)catalysts is critical in the field of water electrolysis,however,which is severely hampered by the sluggish kinetics in alkaline media.Herein,a ruthenium(Ru)incorporation induced vacancy engineering strategy is firstly proposed to precisely construct oxygen vacancy(V_(O))-riched cobalt-ruthenium metaphosphate(CRPO)for high-efficiency pH-universal HER.The V_(O) modifies the electronic structure,improves the superficial hydrophilic and gas spillover capacity,it also reduces the coordination number of Ru atoms and regulates the coordination environment.Theoretical calculations indicate that Ru tends to adsorb H_(2)O and H^(*),whereas V_(O) tends to adsorb OH^(-),which greatly promotes the H_(2)O adsorption and the dissociation of HO-H bond.Ultimately,CRPO-2 exhibits remarkable HER performance,the mass activity is about 18.34,21.73,and 38.07 times higher than that of Pt/C in acidic,neutral,and alkaline media,respectively,at the same time maintain excellent stability.Our findings may pave a new avenue for the rational design of electrocatalysts toward pH-universal water electrolysis.展开更多
materials,despite its intensive application in Li/Na-ion batteries.The existing mechanisms of AVE's effects mainly focus on charge transfer but fail to clarify other critical issues.Here,we propose a new insight i...materials,despite its intensive application in Li/Na-ion batteries.The existing mechanisms of AVE's effects mainly focus on charge transfer but fail to clarify other critical issues.Here,we propose a new insight into AVE's effect on K-ion storage by introducing Te vacancies into a representative conversion-type NiTe.In addition to existing mechanisms,we demonstrate Te vacancies play three other unprecedented roles.(1)Te vacancies minimize the intrinsic volume strain from 15%to 6%,significantly suppressing anode pulverization and element dissolution.(2)Te vacancies induce the in-situ formation of a thin yet robust KF-based inorganic-rich solid electrolyte interphase,further accommodating volume strain and element dissolution.(3)Te vacancies reduce Ni-Te bond lengths and promote K-ion diffusion by modulating local atomic structure.Therefore,NiTe_(1-x)delivers an outstanding cycling performance(229.5 mAh g1 at 3.0 A g^(-1)for 1350 cycles)and rate capability(171.7 mAh g^(-1)at 5.0 A g^(-1)1).Furthermore,NiTe_(1-x)-based full cells showcase a remarkable energy density of 200.4 Wh kg^(-1).This work comprehensively elucidates the AVE's effects on alkali-ion storage,promoting the development of advanced conversion-type anode materials for practical applications.展开更多
Photocatalytic oxidation of toluene to valuable benzaldehyde offers a promising pathway for sustainable production of fine chemicals and pharmaceuticals.In this process,photogenerated holes play a crucial role in C(sp...Photocatalytic oxidation of toluene to valuable benzaldehyde offers a promising pathway for sustainable production of fine chemicals and pharmaceuticals.In this process,photogenerated holes play a crucial role in C(sp^(3))-H bond dissociation.However,the photocatalytic performance of current photocatalysts is often hindered by the low separation and transfer efficiency of photogenerated charges.In this work,we presented a perovskite-based heterostructure via in situ growth of defective WO_(3-x)nanosheets on Cs_(2)AgBiBr_(6)nanoparticles for photocatalytic toluene transformation.In situ Fourier transform infrared spectroscopy tests proved the introduction of oxygen-deficient WO_(3)-xcomponent enhanced the chemisorption of molecular oxygen.The in situ electron paramagnetic resonance and 4-chloro-7-nitro-1,2,3-benzoxadiazole fluorescence measurements further confirmed the presence of oxygen vacancies,and the formation of heterostructure synergistically accelerated the formation of the superoxide radicals and the transfer of photogenerated charge carriers.Under visible light irradiation,Cs_(2)AgBiBr_(6)/WO_(3-x)photocatalyst could effectively oxidize toluene toward benzaldehyde with a conversion rate of 9020μmol g^(-1)h^(-1),which was a 3.5-fold increase over that of the unmodified Cs_(2)AgBiBr_(6).展开更多
Energy band structure and interfacial compatibility of heterojunctions are crucial for photocatalysts in promoting photogene rated charge separation and transfer.Here,a combined strategy of vacancy engineering and qua...Energy band structure and interfacial compatibility of heterojunctions are crucial for photocatalysts in promoting photogene rated charge separation and transfer.Here,a combined strategy of vacancy engineering and quantum effect via a facile phosphating process is reported,for the first time,to modulate the energy band structure and the interface of Zn_(x)Cd_(1-x)S/CoP quantum dots(ZCS_(v)/CoP QDs)heterojunction.The combined experimental and theoretical investigation revealed that phosphating process transformed CoO_(x) QDs to CoP QDs,and more importantly,generated considerable amount of sulfur vacancies in ZCS_(v).As a result,a TypeⅡZCS_(v)/CoP QDs heterojunction with compatible interfaces was constructed via in-situ generated P-Zn,P-Cd and S-Co bonds,which facilitated the separation and transfer of the photogenerated charge and thus resulted in a high ability towards hydrogen evolution under visible light(17.53 mmol g^(-1) h^(-1)).This work provides an effective and adaptable strategy to modulate band structure and interfacial compatibility of heterojunctions via vacancy engineering and quantum effect.展开更多
Single-atom catalysts(SACs)have attracted considerable attention for electrochemical reactions due to their high atomic efficiency and tunable catalytic properties.Here,we systematically investigate the hydrogen evolu...Single-atom catalysts(SACs)have attracted considerable attention for electrochemical reactions due to their high atomic efficiency and tunable catalytic properties.Here,we systematically investigate the hydrogen evolution reaction(HER)activity of transition metal(TM)atoms embedded in hexagonal boron nitride(h-BN)with engineered vacancy defects,leveraging density functional theory(DFT)to examine 28 different TM@BN configurations at both single-and double-vacancy sites.Our calculations show that the TM atoms are strongly bound to the defect sites,ensuring robust structural integrity and resistance to aggregation and leaching under electrochemical conditions.The hydrogen adsorption free energies(ΔG_(H))indicate that Ir@SV-BN,Mo@SV-BN,and Pt@SV-BN exhibit near-optimal adsorption strengths,which was further supported by climbing-image nudged elastic band(CI-NEB)analyses revealing low activation barriers dominated by the Volmer-Heyrovsky mechanism.To expedite the discovery of high-performance catalysts,we employed machine learning(ML)models trained on the high-throughput DFT database,achieving an accuracy of R^(2)=0.96 in predicting overpotentials and identifying key structural and electronic descriptors governing HER activity.Ab initio molecular dynamics(AIMD)simulations confirm the thermal and electrochemical stability of selected TM@BN systems under realistic operational conditions.Taken together,these findings highlight the potential of BN-supported SACs as next-generation electrocatalysts for sustainable hydrogen production and underscore the effectiveness of integrating computational screening,ML-driven optimization,and mechanistic insight to guide the rational design of acid-resistant,high-performance HER catalysts.展开更多
Oxygen vacancies in metal oxides play a pivotal role in determining their electronic structure and interfacial redox dynamics.However,their sluggish kinetics and imbalanced adsorption/desorption hinder their performan...Oxygen vacancies in metal oxides play a pivotal role in determining their electronic structure and interfacial redox dynamics.However,their sluggish kinetics and imbalanced adsorption/desorption hinder their performance.Here,we report oxygen vacancy(OV)-rich molybdenum trioxide(MoO_(3))microbelts for roomtemperature(RT)volatile organic compound(VOC)sensors,effectively overcoming these limitations.Owing to the synergistic effects of a large specific surface area,surface oxygen vacancies,and an optimized electronic structure,exceptional trimethylamine(TMA)sensing performance richs oxygen vacancy-MoO_(3)(MoO_(3−x)-R),including notably high response,rapid response/recovery,high selectivity,a low limit of detection(400 ppb),and reliable operational stability,was achieved.Experimental and density functional theory studies revealed that controlled oxygen vacancies contribute to tuning the surface redox activity of one-dimensional(1D)MoO_(3)and regulating the interfacial electron transfer efficiency.Molecular dynamics(MD)simulations revealed that abundant oxygen vacancies in MoO_(3−x)-R enhance its affinity for TMA while weakening its interaction with nitrogen,carbon dioxide,or water vapor.Furthermore,a portable device was developed for quantitative TMA monitoring,enabling rapid and nondestructive detection of fish freshness.This research provides novel perspectives for designing highperformance gas sensors by optimizing the interfacial redox kinetics.展开更多
Escalating electromagnetic(EM)pollution and advanced stealth technologies require next-generation microwave absorbers that combine broadband response,strong attenuation,and lightweight characteristics with high-temper...Escalating electromagnetic(EM)pollution and advanced stealth technologies require next-generation microwave absorbers that combine broadband response,strong attenuation,and lightweight characteristics with high-temperature stability.In this work,a vacancy-mediated strategy is proposed to tailor EM losses in Cr-doped lanthanum manganite perovskites(LaMn_(1-x)Cr_(x)O_(3))synthesized via a sol–gel method.The cooperative modulation between Mn-site cation vacancies and oxygen vacancies enables a well-balanced contribution of polarization loss and conduction loss,resulting in excellent absorption performance.Specifically,LaMn_(0.85)Cr_(0.15)O_(3) achieves a remarkable minimum reflection loss(RL_(min))of-75.37 dB and an effective absorption bandwidth(EAB)of 6.0 GHz at a thickness of only 2.8 mm.Structural and spectroscopic analyses reveal that Cr^(3+)substitution induces Mn vacancies and modulates oxygen vacancy concentrations,thereby generating defect dipoles and facilitating carrier migration.Density functional theory(DFT)calculations further elucidate the role of Cr-induced defect states in enhancing conduction and polarization losses.This vacancy-engineered approach not only establishes a new paradigm for designing high-efficiency perovskite-based microwave absorbers but also offers significant potential for high-temperature EM compatibility applications.展开更多
The light absorption properties of semiconductor-based photocatalysts to a large extent determine the relevant catalytic performance.Traditional strategies in broadening the light absorption range are usually accompan...The light absorption properties of semiconductor-based photocatalysts to a large extent determine the relevant catalytic performance.Traditional strategies in broadening the light absorption range are usually accompanied with unfavorable changes in redox ability and dynamics of photoinduced species that would confuse the comprehensive optimization.In this work,we propose a nontrivial excitonic transition regulation strategy for gaining sub-bandgap light absorption in low-dimensional semiconductor-based photocatalysts.Using bismuth oxybromide(BiOBr)as a model system,we highlight that the light absorption cut-off edge could be effectively extended up to 500 nm by introducing Bi vacancies.On the basis of theoretical simulations and spectroscopic analyses,we attributed the broadening of light absorption to the promotion of excitonic transition that is generally forbidden in pristine BiOBr system,associated with Bi-vacancy-induced excited-state symmetry breaking.In addition,Bi vacancy was demonstrated to implement negligible effects on other photoexcitation properties like excited-state energy-level profiles and kinetics.Benefiting from these features,the defective sample exhibits a notable advantage in gaining visible-light-driven photocatalytic reactions.展开更多
Spinel LiMn_(2)O_(4)(LMO)is deemed to be a promising cathode material for commercial lithium-ion batteries(LIBs)in prospect of its cost-effectiveness,nontoxicity,fabulous rate capability,and high energy density.Nevert...Spinel LiMn_(2)O_(4)(LMO)is deemed to be a promising cathode material for commercial lithium-ion batteries(LIBs)in prospect of its cost-effectiveness,nontoxicity,fabulous rate capability,and high energy density.Nevertheless,the LMO is inevitably confronted with sluggish diffusion kinetics and drastic capacity degradation triggered by multiple issues,including Jahn-Teller distortion,Mn dissolution,and structural attenuation.Thereinto,a metal-organic framework(MOF)chemistry engineering for hierarchical micro-/nano-structural F,O-dual-doped carbon embedded oxygen vacancy enriched LiMn_(2)O_(4)cathode(OV-LMO@FOC)is proposed for longevous LIBs.Bestowed by experimental and theoretical implementations,systematic investigations of OV-LMO@FOC endow that the meticulous integration of F,O-dual-doped carbon and oxygen vacancy in LMO-based cathode reconfigures the electronic structure,boosts electronic conductivity,expedites diffusion capability,facilitates energetically preferable Li^(+) adsorption,and suppresses Mn dissolution in the electrolyte,consequently achieving fabulous long-term cycling stability.As expected,the OV-LMO@FOC behaves with compelling electrochemical performance with prosperous reversible capacity(130.2 mAh g^(−1)at 0.2 C upon 200 cycles),exceptional rate capacity(93.7 mAh g^(−1) even at 20 C),and pronounced long-term cyclability(112.5 mAh g^(−1)after 1200 cycles with 77.6%capacity retention at 1 C).Even at the ultrahigh current density of 5 C,the OV-LMO@FOC bears a brilliant capacity of 96.9 mAh g^(−1)upon 1000 cycles with an extraordinary capacity retention of 90.7%,and maintains a discharge capacity of 70.9 mAh g^(−1)upon 4000 cycles.This work envisions the MOF-chemistry in surface modification and electronic modulation engineering of high-performance cathode materials towards industrialization in automotive market.展开更多
The introduction of vacancy defects in semiconductors has been proven to be a highly effective approach to improve their photocatalytic activity owing to their advantages of promoting light absorption,facilitating pho...The introduction of vacancy defects in semiconductors has been proven to be a highly effective approach to improve their photocatalytic activity owing to their advantages of promoting light absorption,facilitating photogenerated carrier separation,optimizing electronic structure,and enabling the production of reactive radicals.Herein,we outline the state-of-the-art vacancy-engineered photocatalysts in various applications and reveal how the vacancies influence photocatalytic performance.Specifically,the types of vacancy defects,the methods for tailoring vacancies,the advanced characteri-zation techniques,the categories of photocatalysts with vacancy defects,and the corresponding photocatalytic behaviors are presented.Meanwhile,the methods of vacancies creation and the related photocatalytic performance are correlated,which can be very useful to guide the readers to quickly obtain in-depth knowledge and to have a good idea about the selection of defect engineering methods.The precise characterization of vacancy defects is highly challenging.This review describes the accurate use of a series of characterization techniques with detailed comments and suggestions.This represents the uniqueness of this comprehensive review.The challenges and development prospects in engineering photocatalysts with vacancy defects for practical applications are discussed to provide a promising research direction in this field.展开更多
The rate-determining process for sodium storage in TiO2 is greatly depending on charge transfer happening in the electrode materials owing to its inferior diffusion coefficient and electronic conductivity.Apart from r...The rate-determining process for sodium storage in TiO2 is greatly depending on charge transfer happening in the electrode materials owing to its inferior diffusion coefficient and electronic conductivity.Apart from reducing the diffusion distance of ion/electron,the increasement of ionic/electronic mobility in the crystal lattice is also very important for charge transport.Here,an oxygen vacancy(OV)engineering assisted in high-content anion(S/Se/P)doping strategy to enhance charge transfer kinetics for ultrafast sodium-storage performance is proposed.Theoretical calculations indicate that OV-engineering evokes spontaneous S doping into the TiO2 phase and achieves high dopant concentration to bring about impurity state electron donor and electronic delocalization over S occupied sites,which can largely reduce the migration barrier of Na+.To realize the speculation,high-content anion doped anatase TiO2/C composites(9.82 at%for S in A-TiO2–x-S/C)are elaborately designed.The optimized A-TiO2–x-S/C anode exhibits extraordinarily high-rate capability with 209.6 mAh g-1at 5000 mA g-1.The assembled sodium ion capacitors deliver an ultrahigh energy density of 150.1 Wh kg-1at a power density of 150 W kg-1when applied as anode materials.This work provides a new strategy to realize high content anion doping concentration,and enhances the charge transfer kinetics for TiO2,which delivers an efficient approach for the design of electrode materials with fast kinetic.展开更多
Activating basal plane inert sites will endow MoTe_(2) with prominent hydrogen evolution reaction(HER)catalytic capability and arouse a new family of HER catalysts.Herein,we fabricated single MoTe_(2) sheet electrocat...Activating basal plane inert sites will endow MoTe_(2) with prominent hydrogen evolution reaction(HER)catalytic capability and arouse a new family of HER catalysts.Herein,we fabricated single MoTe_(2) sheet electrocatalytic microdevice for in situ revealing the activated basal plane sites by vacancies introducing.Through the extraction of electrical parameters of single MoTe_(2) sheet,the in-plane and interlayer conductivities were optimized effectively by Te vacancies due to the defect levels.More deeply,Te vacancies can induce the delocalization of electrons around Mo atoms and shift the d-band center,as a consequence,facilitate the adsorption of H from the catalyst surface for HER catalysis.Benefiting by the coordinated regulation of band structure and local charge density,the overpotential at−10 mA·cm^(−2)was reduced to 0.32 V after Te vacancies compared to 0.41 V for the basal plane sites of same MoTe_(2) nanosheet.Meanwhile,the insights gained from single nanosheet electrocatalytic microdevice can be applied to the improved HER of the commercial MoTe_(2) power.That the in situ testing of the atomic structure-electrical behavior-electrochemical properties of a single nanosheet before/after vacancies introducing provides reliable insight to structure-activity relationships.展开更多
Regulated cell death(RCD)is considered a vital process in cancer therapy,determining treatment outcomes and facilitating the eradication of cancer cells.As an emerging type of RCD,PANoptosis features excellent antineo...Regulated cell death(RCD)is considered a vital process in cancer therapy,determining treatment outcomes and facilitating the eradication of cancer cells.As an emerging type of RCD,PANoptosis features excellent antineoplastic effects due to its combination of death modes,including pyroptosis,apoptosis,and necroptosis.In this work,anion‐cation vacancies(oxygen/titanium‐vacancy‐rich)ultrathin HTiO nanosheets with outstanding sonocatalytic performance and peroxidase‐mimicking activity are rationally engineered for the disruption of mitochondrial function in tumor cells and the destabilization of redox homeostasis,ultimately inducing tumor PANoptosis.The utilization of external ultrasound energy amplifies the production of toxic reactive oxygen species(ROS).Density functional theory calculations indicate that the oxygen and titanium vacancies generated in HTiO nanosheets enhance the ROS generation efficiency by promoting carrier separation and increasing the adsorption capacity of H_(2)O_(2).The advantages of triggering PANoptosis are substantially evidenced by exceptional antineoplastic efficacy both at the cellular level and on two in vivo separate tumor xenografts(4T1 and MDA‐MB‐231 breast tumors).This work highlights a distinct type of titanium‐based nanostructure with a multimodal synergistic integration of sonocatalytic and enzymatic therapies,offering an alternative but highly efficient strategy for fabricating vacancy‐engineered sonocatalytic biomaterials with optimized therapeutic performance in tumor treatment.展开更多
基金financially supported by Qing dao Post-doctoral Applied Research Project(No.QDBS H20220202040)the Natural Science Foundation of Shand ong Province,China(No ZR2021QE192)the Postdoctoral Science Foundation of China(No2018M63074)。
文摘The high-energy-density and low-cost features endow lithium-sulfur batteries with broad application prospects.However,many drawbacks,especially the detrimental shuttle effect,have hindered the further development of LSBs.In response,a lot of new structures have been applied to suppress the shuttle effect and promote the development of LSBs.Recently,vacancy engineering has gained the attention of researchers due to its unique electronic structure.This review aims to analyze the application of vacancy engineering in LSBs.Firstly,the electrochemistry of LSBs has been systematically discussed and the existing challenges as well as improvement tactics of LSBs have also been presented.Subsequently,the preparation methods and characterization technologies of various vacancies are summarized,including oxygen vacancies,sulfur vacancies,selenium vacancies,other anion vacancies,cation vacancies,etc.The latest applications of vacancy engineering in LSBs are also summarized in this review.Finally,some prospects and insights for further investigation and practical application of vacancy engineering in LSBs are put forward.
文摘Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme heterojunction with O and Zn vacancies(VO,Zn-ZnO/ZnS)is rationally constructed via ion-exchange and calcination treatments.In such a photocatalytic system,the hollow structure combined with the introduction of dual vacancies endows the adequate light absorption.Moreover,the O and Zn vacancies serve as the trapping sites for photo-induced electrons and holes,respectively,which are beneficial for promoting the photo-induced carrier separation.Meanwhile,the S-scheme charge transfer mechanism can not only improve the separation and transfer efficiencies of photo-induced carrier but also retain the strong redox capacity.As expected,the optimized VO,Zn-ZnO/ZnS heterojunction exhibits a superior photocatalytic H_(2) production rate of 160.91 mmol g^(-1)h^(-1),approximately 643.6 times and 214.5 times with respect to that obtained on pure ZnO and ZnS,respectively.Simultaneously,the experimental results and density functional theory calculations disclose that the photo-induced carrier transfer pathway follows the S-scheme heterojunction mechanism and the introduction of O and Zn vacancies reduces the surface reaction barrier.This work provides an innovative strategy of vacancy engineering in S-scheme heterojunction for solar-to-fuel energy conversion.
基金financially supported by China Postdoctoral Science Foundation (2019M652305)Qingdao Postdoctoral Application Research Project。
文摘The artificial nitrogen(N_(2)) reduction reaction(NRR) via electrocatalysis is a newly developed methodology to produce ammonia(NH3) at ambient conditions,but faces the challenges in N_(2)activation and poor reaction selectivity.Herein,Nb-based MXenes are developed to remarkably enhance the NRR activity through the engineering of the stretched 3D structure and oxygen vacancies(VO).The theoretical studies indicate that N_(2)could be initially adsorbed on VOwith an end-on configuration,and the potential determining step might be the first hydrogenation step.The catalysts achieve an NH3production rate of 29.1 μg h^(-1)mg_(cat)^(-1)and excellent Faradic efficiency of 11.5%,surpassing other Nbbased catalysts.The selectivity of NRR is assigned to the unique structure of the catalysts,including(1) the layered graphitic structure for fast electron transfer and active site distribution,(2) the reactive VOfor N_(2)adsorption and activation,and(3) the expanded interlayer space for mass transfer.
基金financially supported by the National Natural Science Foundation of China (Nos.52173055,21961132024 and 51925302)the Natural Science Foundation of Shanghai (No.19ZR1401100)+3 种基金the Innovation Program of Shanghai Municipal Education Commission (No.2017-01-07-00-03-E00024)the Fundamental Research Funds for the Central Universities (No.CUSF-DH-D-2019028)the DHU Distinguished Young Professor Program (No.LZA2020001)financial support from DFG (No.431073172)。
文摘Electrocatalysis plays an increasingly important role in converting atmospheric molecules(e.g.,N_(2),CO_(2) and H_(2)O)to value-added products(e.g.,NH_(3),C_(2)H_(4)and H_(2)).However,developing a simple strategy for preparing catalysts with high performance for the effective conversion of clean energy is still full of chal-lenges.Herein,we describe a straightforward,one-step reduction method to achieve the formation of Pt nanoparticles(NPs)and the vacancy engineering of TiO_(2-x)nanofibers(NFs)simultaneously,which can be accomplished in 5 min.Furthermore,a Pt/TiO_(2-x)nanofibrous aerogel(NA)with an ordered cellular archi-tecture is prepared through a directional freezing technology.The Pt/TiO_(2-x)NA with excellent mechanical properties can be made into a self-supporting electrode for electrocatalytic N_(2)reduction reaction(NRR),showing high NH_(3) yield rate(4.81×10^(-10)mol/s cm^(-2))and Faraday efficiency(14.9%)at-0.35 V vs.RHE.
基金supported by the New&Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resource from the Ministry of Trade,Industry&Energy(MOTIE),Republic of Korea(No.20213091010020)National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(2020R1A2C1101085)+2 种基金the Korea Institute of Planning and Evaluation for Technology in Food,Agriculture and Forestry(IPET)and Korea Smart Farm R&D Foundation(KosFarm)through Smart Farm Innovation Technology Development Programfunded by the Ministry of Agriculture,Food and Rural Affairs(MAFRA)the Ministry of Science and ICT(MSIT),Rural Development Administration(RDA)(421036-03).
文摘Electron transport layer(ETL)is pivotal to charge carrier transport for PSCs to reach the Shockley-Queisser limit.This study provides a fundamental understanding of heterojunction electron transport layers(ETLs)at the atomic level for stable and efficient perovskite solar cells(PSCs).The bilayer structure of an ETL composed of SnO_(2) on TiO_(2) was examined,revealing a critical factor limiting its potential to obtain efficient performance.Alteration of oxygen vacancies in the TiO_(2) underlayer via an annealing process is found to induce manipulated band offsets at the interface between the TiO_(2) and SnO_(2) layers.In-depth electronic investigations of the bilayer structure elucidate the importance of the electronic properties at the interface between the TiO_(2) and SnO_(2) layers.The apparent correlation in hysteresis phenomena,including current density-voltage(J-V)curves,appears as a function of the type of band alignment.Density functional theory calculations reveal the intimate relationship between oxygen vacancies,deep trap states,and charge transport efficiency at the interface between the TiO_(2) and SnO_(2) layers.The formation of cascade band alignment via control over the TiO_(2) underlayer enhances device performance and suppresses hysteresis.Optimal performance exhibits a power conversion efficiency(PCE)of 23.45%with an open-circuit voltage(V_(oc))of 1.184 V,showing better device stability under maximum power point tracking compared with a staggered bilayer under one-sun continuous illumination.
基金supported by the National Science Basic Research Program of Shaanxi(Nos.2024JC-YBQN-0103,2024JC-YBMS-127,2022JQ-102)the National Natural Science Foundation of China(No.52073228)the Xi’an Shiyou University Postgraduate Innovation and Practical Ability Training Project(No.YCS23213089).
文摘Among the many strategies for CO_(2)resource utilization,the synthetic technology of cyclic carbonates with 100%atom economy through CO_(2)and epoxide is one of the most industrially viable routes,but its efficiency has been severely hampered by the lack of highly active catalytic sites.Moreover,due to the intrinsic thermodynamic stability and kinetic inertia of CO_(2)and the higher energy barrier of the ring-opening reaction of epoxides,the heterogeneous catalytic conversion of CO_(2)highly depends on harsh operating conditions,high temperatures and pressures,and the incorporation of cocatalysts.The devel-opment of efficient heterogeneous catalysts for CO_(2)conversion under cocatalyst-free and mild conditions has always been a challenge.Herein,we have proposed a synergetic strategy of facet and vacancy engi-neering for the construction of highly efficient heterogeneous catalyst BiO1-x Br1-y-(010)for CO_(2)cycload-dition,where introducing the OVs-BrVs pairs into typical(010)facets BiOBr with simultaneous surface Lewis acid sites Bi^(3+)and nucleophilic sites Br^(−).By combining theoretical calculations and a series of systematic experiments,such as CO_(2)temperature-programmed desorption,electron paramagnetic res-onance and fluorescence probe analysis experiments,the introduced OVs-BrVs pair can not only form Bi^(3+)-Bi^(3-x)+dual active sites on the surface,which activate PO and CO_(2)respectively to reduce the energy barrier of CO_(2)insertion,but also activate Br^(−)near BrVs to enhance their nucleophilic attacking ability and reduce the energy barrier of epoxides ring-opening.As a result,the BiO1-x Br1-y-(010)with abundant surface OVs-BrVs pairs showed a high cyclic carbonates conversion of 99%with 100%selectivity un-der cocatalyst-free and mild conditions,far surpassing most heterogeneous catalytic systems.This work provides a completely new strategy to construct high-performance heterogeneous CO_(2)cycloaddition cata-lysts through a simple facet and vacancy engineering strategy to overcome the harsh operating conditions limitation and the use of cocatalysts.
基金supported by the King Abdullah University of Science and Technology(KAUST)。
文摘In contrast to alkaline water electrolysis,acidic water electrolysis remains an elusive goal due to the lack of earth-abundant,efficient,and acid-stable water oxidation electrocatalysts.Here,we show that materials with intrinsically poor electrocatalytic activity can be turned into active electrocatalysts that drive the acidic oxygen evolution reaction(OER)effectively.This development is achieved through ultrafast plasma sputtering,which introduces abundant oxygen vacancies that reconstruct the surface electronic structures,and thus,regulated the surface interactions of electrocatalysts and the OER intermediates.Using tungsten oxide(WO_(3))as an example,we present a broad spectrum of theoretical and experimental characterizations that show an improved energetics of OER originating from surface oxygen vacancies and resulting in a significantly boosted OER performance,compared with pristine WO_(3).Our result suggests the efficacy of using defect chemistry to modify electronic properties and hence to improve the OER performance of known materials with poor activity,providing a new direction for the discovery of acid-stable OER catalysts.
基金supported by National Natural Science Foundation of China(Nos.21721003,22202080,22034006).
文摘Developing efficient pH-universal hydrogen evolution reaction(HER)catalysts is critical in the field of water electrolysis,however,which is severely hampered by the sluggish kinetics in alkaline media.Herein,a ruthenium(Ru)incorporation induced vacancy engineering strategy is firstly proposed to precisely construct oxygen vacancy(V_(O))-riched cobalt-ruthenium metaphosphate(CRPO)for high-efficiency pH-universal HER.The V_(O) modifies the electronic structure,improves the superficial hydrophilic and gas spillover capacity,it also reduces the coordination number of Ru atoms and regulates the coordination environment.Theoretical calculations indicate that Ru tends to adsorb H_(2)O and H^(*),whereas V_(O) tends to adsorb OH^(-),which greatly promotes the H_(2)O adsorption and the dissociation of HO-H bond.Ultimately,CRPO-2 exhibits remarkable HER performance,the mass activity is about 18.34,21.73,and 38.07 times higher than that of Pt/C in acidic,neutral,and alkaline media,respectively,at the same time maintain excellent stability.Our findings may pave a new avenue for the rational design of electrocatalysts toward pH-universal water electrolysis.
基金support from the National Natural Science Foundation of China(No.U23A20574,52201242)the Natural Science Foundation of Jiangsu Province(No.BK20240179).
文摘materials,despite its intensive application in Li/Na-ion batteries.The existing mechanisms of AVE's effects mainly focus on charge transfer but fail to clarify other critical issues.Here,we propose a new insight into AVE's effect on K-ion storage by introducing Te vacancies into a representative conversion-type NiTe.In addition to existing mechanisms,we demonstrate Te vacancies play three other unprecedented roles.(1)Te vacancies minimize the intrinsic volume strain from 15%to 6%,significantly suppressing anode pulverization and element dissolution.(2)Te vacancies induce the in-situ formation of a thin yet robust KF-based inorganic-rich solid electrolyte interphase,further accommodating volume strain and element dissolution.(3)Te vacancies reduce Ni-Te bond lengths and promote K-ion diffusion by modulating local atomic structure.Therefore,NiTe_(1-x)delivers an outstanding cycling performance(229.5 mAh g1 at 3.0 A g^(-1)for 1350 cycles)and rate capability(171.7 mAh g^(-1)at 5.0 A g^(-1)1).Furthermore,NiTe_(1-x)-based full cells showcase a remarkable energy density of 200.4 Wh kg^(-1).This work comprehensively elucidates the AVE's effects on alkali-ion storage,promoting the development of advanced conversion-type anode materials for practical applications.
基金supported by the National Key Research and Development Program of China(No.2021YFA1600800)the National Natural Science Foundation of China(Nos.22102102,22372102,22101185 and 22402122)+8 种基金Shenzhen Science and Technology Program(No.20231122120657001)the City University of Hong Kong Start-Up Fund(No.9020003)ITFRTH-Global STEM Professorship(No.9446006)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010982)Research Team Cultivation Program of Shenzhen University(No.2023QNT013)Scientific Foundation for Youth Scholars of Shenzhen University(868-000001032185)Shenzhen Peacock Plan(Nos.20210308299C,RCJC20200714114434086 and 20231121175024001)Shenzhen Key Laboratory of 2D Metamaterials for Information Technology(No.ZDSYS201707271014468)China Postdoctoral Science Foundation(No.2023M742395)
文摘Photocatalytic oxidation of toluene to valuable benzaldehyde offers a promising pathway for sustainable production of fine chemicals and pharmaceuticals.In this process,photogenerated holes play a crucial role in C(sp^(3))-H bond dissociation.However,the photocatalytic performance of current photocatalysts is often hindered by the low separation and transfer efficiency of photogenerated charges.In this work,we presented a perovskite-based heterostructure via in situ growth of defective WO_(3-x)nanosheets on Cs_(2)AgBiBr_(6)nanoparticles for photocatalytic toluene transformation.In situ Fourier transform infrared spectroscopy tests proved the introduction of oxygen-deficient WO_(3)-xcomponent enhanced the chemisorption of molecular oxygen.The in situ electron paramagnetic resonance and 4-chloro-7-nitro-1,2,3-benzoxadiazole fluorescence measurements further confirmed the presence of oxygen vacancies,and the formation of heterostructure synergistically accelerated the formation of the superoxide radicals and the transfer of photogenerated charge carriers.Under visible light irradiation,Cs_(2)AgBiBr_(6)/WO_(3-x)photocatalyst could effectively oxidize toluene toward benzaldehyde with a conversion rate of 9020μmol g^(-1)h^(-1),which was a 3.5-fold increase over that of the unmodified Cs_(2)AgBiBr_(6).
基金financially supported by the Taishan Scholar Program of Shandong Province(ts201712046)the Key Research and Development Programme of Shandong Province(2019JZZY010905)+2 种基金the Natural Science Foundation of Shandong Province(ZR2020QB132)the Liaoning BaiQianWan Talents Programthe Royal Society and the Newton Fund(NAF\R1\191294)。
文摘Energy band structure and interfacial compatibility of heterojunctions are crucial for photocatalysts in promoting photogene rated charge separation and transfer.Here,a combined strategy of vacancy engineering and quantum effect via a facile phosphating process is reported,for the first time,to modulate the energy band structure and the interface of Zn_(x)Cd_(1-x)S/CoP quantum dots(ZCS_(v)/CoP QDs)heterojunction.The combined experimental and theoretical investigation revealed that phosphating process transformed CoO_(x) QDs to CoP QDs,and more importantly,generated considerable amount of sulfur vacancies in ZCS_(v).As a result,a TypeⅡZCS_(v)/CoP QDs heterojunction with compatible interfaces was constructed via in-situ generated P-Zn,P-Cd and S-Co bonds,which facilitated the separation and transfer of the photogenerated charge and thus resulted in a high ability towards hydrogen evolution under visible light(17.53 mmol g^(-1) h^(-1)).This work provides an effective and adaptable strategy to modulate band structure and interfacial compatibility of heterojunctions via vacancy engineering and quantum effect.
基金supported by the Soonchunhyang University Research Fundthe Supercomputing Center/Korea Institute of Science and Technology Information with supercomputing resources(TS-2024-RE-0041)+3 种基金Following are the results of a study on the“Leaders in INdustry-university Cooperation 3.0”Project,supported by the Ministry of Education and National Research Foundation of Koreasupported by the Technology Innovation Program(20023140,Development of an integrated low-power,high-performance,cryogenic high-vacuum exhaust system for analyzing impurity concentrations in the process in real time)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)supported by the Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(RS-2024-00409639,HRD Program for Industrial Innovation)supported by the BK21 Four Program funded by the Ministry of Education(MOE,Korea)and the National Research Foundation of Korea(NRF),and in part by INHA university research grant.
文摘Single-atom catalysts(SACs)have attracted considerable attention for electrochemical reactions due to their high atomic efficiency and tunable catalytic properties.Here,we systematically investigate the hydrogen evolution reaction(HER)activity of transition metal(TM)atoms embedded in hexagonal boron nitride(h-BN)with engineered vacancy defects,leveraging density functional theory(DFT)to examine 28 different TM@BN configurations at both single-and double-vacancy sites.Our calculations show that the TM atoms are strongly bound to the defect sites,ensuring robust structural integrity and resistance to aggregation and leaching under electrochemical conditions.The hydrogen adsorption free energies(ΔG_(H))indicate that Ir@SV-BN,Mo@SV-BN,and Pt@SV-BN exhibit near-optimal adsorption strengths,which was further supported by climbing-image nudged elastic band(CI-NEB)analyses revealing low activation barriers dominated by the Volmer-Heyrovsky mechanism.To expedite the discovery of high-performance catalysts,we employed machine learning(ML)models trained on the high-throughput DFT database,achieving an accuracy of R^(2)=0.96 in predicting overpotentials and identifying key structural and electronic descriptors governing HER activity.Ab initio molecular dynamics(AIMD)simulations confirm the thermal and electrochemical stability of selected TM@BN systems under realistic operational conditions.Taken together,these findings highlight the potential of BN-supported SACs as next-generation electrocatalysts for sustainable hydrogen production and underscore the effectiveness of integrating computational screening,ML-driven optimization,and mechanistic insight to guide the rational design of acid-resistant,high-performance HER catalysts.
基金supported by the National Natural Science Foundation of China(No.52402202)the Natural Science Youth Foundation of Jiangsu Province of China(No.BK20240933)+2 种基金the Outstanding Youth Foundation of Jiangsu Province of China(No.BK20211548)the Yangzhou Science and Technology Plan Project(No.YZ2023246)Qinglan Project of Yangzhou University.
文摘Oxygen vacancies in metal oxides play a pivotal role in determining their electronic structure and interfacial redox dynamics.However,their sluggish kinetics and imbalanced adsorption/desorption hinder their performance.Here,we report oxygen vacancy(OV)-rich molybdenum trioxide(MoO_(3))microbelts for roomtemperature(RT)volatile organic compound(VOC)sensors,effectively overcoming these limitations.Owing to the synergistic effects of a large specific surface area,surface oxygen vacancies,and an optimized electronic structure,exceptional trimethylamine(TMA)sensing performance richs oxygen vacancy-MoO_(3)(MoO_(3−x)-R),including notably high response,rapid response/recovery,high selectivity,a low limit of detection(400 ppb),and reliable operational stability,was achieved.Experimental and density functional theory studies revealed that controlled oxygen vacancies contribute to tuning the surface redox activity of one-dimensional(1D)MoO_(3)and regulating the interfacial electron transfer efficiency.Molecular dynamics(MD)simulations revealed that abundant oxygen vacancies in MoO_(3−x)-R enhance its affinity for TMA while weakening its interaction with nitrogen,carbon dioxide,or water vapor.Furthermore,a portable device was developed for quantitative TMA monitoring,enabling rapid and nondestructive detection of fish freshness.This research provides novel perspectives for designing highperformance gas sensors by optimizing the interfacial redox kinetics.
基金financial support from the Defense Industrial Technology Development Program(JCKY2023603C016).
文摘Escalating electromagnetic(EM)pollution and advanced stealth technologies require next-generation microwave absorbers that combine broadband response,strong attenuation,and lightweight characteristics with high-temperature stability.In this work,a vacancy-mediated strategy is proposed to tailor EM losses in Cr-doped lanthanum manganite perovskites(LaMn_(1-x)Cr_(x)O_(3))synthesized via a sol–gel method.The cooperative modulation between Mn-site cation vacancies and oxygen vacancies enables a well-balanced contribution of polarization loss and conduction loss,resulting in excellent absorption performance.Specifically,LaMn_(0.85)Cr_(0.15)O_(3) achieves a remarkable minimum reflection loss(RL_(min))of-75.37 dB and an effective absorption bandwidth(EAB)of 6.0 GHz at a thickness of only 2.8 mm.Structural and spectroscopic analyses reveal that Cr^(3+)substitution induces Mn vacancies and modulates oxygen vacancy concentrations,thereby generating defect dipoles and facilitating carrier migration.Density functional theory(DFT)calculations further elucidate the role of Cr-induced defect states in enhancing conduction and polarization losses.This vacancy-engineered approach not only establishes a new paradigm for designing high-efficiency perovskite-based microwave absorbers but also offers significant potential for high-temperature EM compatibility applications.
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1502903 and 2021YFA1501502)the Strategic Priority Research Program of Chinese Academy of Sciences(Nos.XDB36000000 and XDB0450102)+3 种基金the National Natural Science Foundation of China(22275179)the Anhui Provincial Key Research and Development Program(No.2022a05020054)the Youth Innovation Promotion Association of CAS(No.Y2021123)the Fundamental Research Funds for the Central Universities(No.WK2060000039)。
文摘The light absorption properties of semiconductor-based photocatalysts to a large extent determine the relevant catalytic performance.Traditional strategies in broadening the light absorption range are usually accompanied with unfavorable changes in redox ability and dynamics of photoinduced species that would confuse the comprehensive optimization.In this work,we propose a nontrivial excitonic transition regulation strategy for gaining sub-bandgap light absorption in low-dimensional semiconductor-based photocatalysts.Using bismuth oxybromide(BiOBr)as a model system,we highlight that the light absorption cut-off edge could be effectively extended up to 500 nm by introducing Bi vacancies.On the basis of theoretical simulations and spectroscopic analyses,we attributed the broadening of light absorption to the promotion of excitonic transition that is generally forbidden in pristine BiOBr system,associated with Bi-vacancy-induced excited-state symmetry breaking.In addition,Bi vacancy was demonstrated to implement negligible effects on other photoexcitation properties like excited-state energy-level profiles and kinetics.Benefiting from these features,the defective sample exhibits a notable advantage in gaining visible-light-driven photocatalytic reactions.
基金the financial support from the Open Fund of Energy and Materials Chemistry Joint Laboratory of SCNU and TINCI,China(SCNU-TINCI-202207)supported by the Natural Science Foundation of China(No.52302283).
文摘Spinel LiMn_(2)O_(4)(LMO)is deemed to be a promising cathode material for commercial lithium-ion batteries(LIBs)in prospect of its cost-effectiveness,nontoxicity,fabulous rate capability,and high energy density.Nevertheless,the LMO is inevitably confronted with sluggish diffusion kinetics and drastic capacity degradation triggered by multiple issues,including Jahn-Teller distortion,Mn dissolution,and structural attenuation.Thereinto,a metal-organic framework(MOF)chemistry engineering for hierarchical micro-/nano-structural F,O-dual-doped carbon embedded oxygen vacancy enriched LiMn_(2)O_(4)cathode(OV-LMO@FOC)is proposed for longevous LIBs.Bestowed by experimental and theoretical implementations,systematic investigations of OV-LMO@FOC endow that the meticulous integration of F,O-dual-doped carbon and oxygen vacancy in LMO-based cathode reconfigures the electronic structure,boosts electronic conductivity,expedites diffusion capability,facilitates energetically preferable Li^(+) adsorption,and suppresses Mn dissolution in the electrolyte,consequently achieving fabulous long-term cycling stability.As expected,the OV-LMO@FOC behaves with compelling electrochemical performance with prosperous reversible capacity(130.2 mAh g^(−1)at 0.2 C upon 200 cycles),exceptional rate capacity(93.7 mAh g^(−1) even at 20 C),and pronounced long-term cyclability(112.5 mAh g^(−1)after 1200 cycles with 77.6%capacity retention at 1 C).Even at the ultrahigh current density of 5 C,the OV-LMO@FOC bears a brilliant capacity of 96.9 mAh g^(−1)upon 1000 cycles with an extraordinary capacity retention of 90.7%,and maintains a discharge capacity of 70.9 mAh g^(−1)upon 4000 cycles.This work envisions the MOF-chemistry in surface modification and electronic modulation engineering of high-performance cathode materials towards industrialization in automotive market.
基金This study was also supported by the European Commission Interreg V France-Wallonie-Vlaanderen project“DepollutAir.”Yang Ding is grateful for the financial support of the China Scholarship Council(201808310127)This study was financially supported by the National Natural Science Foundation of China(U20A20122)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R52)of the Chinese Ministry of Education,the Program of Introducing Talents of Discipline to Universities-Plan 111(Grant No.B20002)the Ministry of Science and Technology and the Ministry of Education of China,and the National Key R&D Program of China(2016YFA0202602).
文摘The introduction of vacancy defects in semiconductors has been proven to be a highly effective approach to improve their photocatalytic activity owing to their advantages of promoting light absorption,facilitating photogenerated carrier separation,optimizing electronic structure,and enabling the production of reactive radicals.Herein,we outline the state-of-the-art vacancy-engineered photocatalysts in various applications and reveal how the vacancies influence photocatalytic performance.Specifically,the types of vacancy defects,the methods for tailoring vacancies,the advanced characteri-zation techniques,the categories of photocatalysts with vacancy defects,and the corresponding photocatalytic behaviors are presented.Meanwhile,the methods of vacancies creation and the related photocatalytic performance are correlated,which can be very useful to guide the readers to quickly obtain in-depth knowledge and to have a good idea about the selection of defect engineering methods.The precise characterization of vacancy defects is highly challenging.This review describes the accurate use of a series of characterization techniques with detailed comments and suggestions.This represents the uniqueness of this comprehensive review.The challenges and development prospects in engineering photocatalysts with vacancy defects for practical applications are discussed to provide a promising research direction in this field.
基金supported by the National Key Research and Development Program of China(2019YFC1907805)the National Natural Science Foundation of China(52004338)+1 种基金Hunan Provincial Natural Science Foundation(2020JJ5696)Guangdong Provincial Department of Natural Resources(2020-011)。
文摘The rate-determining process for sodium storage in TiO2 is greatly depending on charge transfer happening in the electrode materials owing to its inferior diffusion coefficient and electronic conductivity.Apart from reducing the diffusion distance of ion/electron,the increasement of ionic/electronic mobility in the crystal lattice is also very important for charge transport.Here,an oxygen vacancy(OV)engineering assisted in high-content anion(S/Se/P)doping strategy to enhance charge transfer kinetics for ultrafast sodium-storage performance is proposed.Theoretical calculations indicate that OV-engineering evokes spontaneous S doping into the TiO2 phase and achieves high dopant concentration to bring about impurity state electron donor and electronic delocalization over S occupied sites,which can largely reduce the migration barrier of Na+.To realize the speculation,high-content anion doped anatase TiO2/C composites(9.82 at%for S in A-TiO2–x-S/C)are elaborately designed.The optimized A-TiO2–x-S/C anode exhibits extraordinarily high-rate capability with 209.6 mAh g-1at 5000 mA g-1.The assembled sodium ion capacitors deliver an ultrahigh energy density of 150.1 Wh kg-1at a power density of 150 W kg-1when applied as anode materials.This work provides a new strategy to realize high content anion doping concentration,and enhances the charge transfer kinetics for TiO2,which delivers an efficient approach for the design of electrode materials with fast kinetic.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21805102,22071069,and 21825103)the Hubei Provincial Natural Science Foundation of China(No.2019CFA002)the Foundation of Basic and Applied Basic Research of Guangdong Province(No.2019B1515120087)。
文摘Activating basal plane inert sites will endow MoTe_(2) with prominent hydrogen evolution reaction(HER)catalytic capability and arouse a new family of HER catalysts.Herein,we fabricated single MoTe_(2) sheet electrocatalytic microdevice for in situ revealing the activated basal plane sites by vacancies introducing.Through the extraction of electrical parameters of single MoTe_(2) sheet,the in-plane and interlayer conductivities were optimized effectively by Te vacancies due to the defect levels.More deeply,Te vacancies can induce the delocalization of electrons around Mo atoms and shift the d-band center,as a consequence,facilitate the adsorption of H from the catalyst surface for HER catalysis.Benefiting by the coordinated regulation of band structure and local charge density,the overpotential at−10 mA·cm^(−2)was reduced to 0.32 V after Te vacancies compared to 0.41 V for the basal plane sites of same MoTe_(2) nanosheet.Meanwhile,the insights gained from single nanosheet electrocatalytic microdevice can be applied to the improved HER of the commercial MoTe_(2) power.That the in situ testing of the atomic structure-electrical behavior-electrochemical properties of a single nanosheet before/after vacancies introducing provides reliable insight to structure-activity relationships.
基金support from the Shanghai Science and Technology Program(Grant 22ZR1476600)Shanghai Shuguang Program(Grant 21SG39)+1 种基金National Natural Science Foundation of China(Grant 82102085)Basic Research Program of Shanghai Municipal Government(Grant 21JC1406002).
文摘Regulated cell death(RCD)is considered a vital process in cancer therapy,determining treatment outcomes and facilitating the eradication of cancer cells.As an emerging type of RCD,PANoptosis features excellent antineoplastic effects due to its combination of death modes,including pyroptosis,apoptosis,and necroptosis.In this work,anion‐cation vacancies(oxygen/titanium‐vacancy‐rich)ultrathin HTiO nanosheets with outstanding sonocatalytic performance and peroxidase‐mimicking activity are rationally engineered for the disruption of mitochondrial function in tumor cells and the destabilization of redox homeostasis,ultimately inducing tumor PANoptosis.The utilization of external ultrasound energy amplifies the production of toxic reactive oxygen species(ROS).Density functional theory calculations indicate that the oxygen and titanium vacancies generated in HTiO nanosheets enhance the ROS generation efficiency by promoting carrier separation and increasing the adsorption capacity of H_(2)O_(2).The advantages of triggering PANoptosis are substantially evidenced by exceptional antineoplastic efficacy both at the cellular level and on two in vivo separate tumor xenografts(4T1 and MDA‐MB‐231 breast tumors).This work highlights a distinct type of titanium‐based nanostructure with a multimodal synergistic integration of sonocatalytic and enzymatic therapies,offering an alternative but highly efficient strategy for fabricating vacancy‐engineered sonocatalytic biomaterials with optimized therapeutic performance in tumor treatment.
