Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modificat...Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modification methods.Constructing defects on the surface of catalytic materials can effectively modulate the coordination environment of the active sites,affecting and changing the electrons,geometry,and other important properties at the catalytic active sites,thus altering the catalytic activity of the catalysts.However,the conformational relationship between defects and catalytic activity remains to be clarified.This dissertation focuses on an overview of recent advances in defect engineering in environmental catalysis.Based on defining the classification of defects in catalytic materials,defect construction methods,and characterization techniques are summarized and discussed.Focusing on an overview of the characteristics of the role of defects in electrocatalytic,photocatalytic,and thermal catalytic reactions and the mechanism of catalytic reactions.An elaborate link is given between the reaction activity and the structure of catalyst defects.Finally,the existing challenges and possible future directions for the application of defect engineering in environmental catalysis are discussed,which are expected to guide the design and development of efficient environmental catalysts and mechanism studies.展开更多
High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,inclu...High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.展开更多
Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,th...Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.展开更多
Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the e...Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.展开更多
Hydrogen peroxide(H_(2)O_(2))photosynthesis represents an advanced on-site production method with significant potential for on-demand supply.However,various challenges hinder the efficiency of H_(2)O_(2) yield,includi...Hydrogen peroxide(H_(2)O_(2))photosynthesis represents an advanced on-site production method with significant potential for on-demand supply.However,various challenges hinder the efficiency of H_(2)O_(2) yield,including weak oxygen adsorption capacity,reliance on sacrificial agents,low charge separation and transfer efficiency.In this regard,doping design and defect engineering have emerged as robust and effective strategies for catalyst modification,particularly through their synergistic effects.Additionally,advanced in situ characterization techniques for investigating reaction mechanisms are gaining momentum.Herein,this review provides a comprehensive analysis of the fundamentals and challenges associated with photocatalytic H_(2)O_(2) production,and highlights the advantages of doping and defect engineering.Subsequently,it outlines preparation methods and applications of these strategies.More importantly,it emphasizes the advanced characterization techniques utilized to validate doping and defects,as well as to investigate underlying mechanisms.Finally,the potential prospects and challenges of this reaction are anticipated.This review aims to offer valuable insights for researchers from both experimental and theoretical perspectives.展开更多
Sustainable energy conversion and storage technologies are a vital prerequisite for neutral future carbon.To this end,carbon materials with attractive features,such as tunable pore architecture,good electrical conduct...Sustainable energy conversion and storage technologies are a vital prerequisite for neutral future carbon.To this end,carbon materials with attractive features,such as tunable pore architecture,good electrical conductivity,outstanding physicochemical stability,abundant resource,and low cost,have used as promising electrode materials for energy conversion and storage.Defect engineering could modulate the structures of carbon materials,thereby affecting their electronic properties.The presence of defects on carbons may lead to asymmetric charge distribution,change in geometrical configuration,and distortion of the electronic structure that may result in unexpected electrochemical performances.In this review,recent advances in defects of carbons used for energy conversion and storage were examined in terms of types,regulation strategies,and fine characterization means of defects.The applications of such carbons in supercapacitors,rechargeable batteries,and electrocatalysis were also discussed.The perspectives toward the development of defect engineering carbons were proposed.In all,novel insights related to improvement in high-performance carbon materials for future energy conversion and storage applications were provided.展开更多
Owing to adjustable microstructure and stable physiochemical properties,carbon-based materials are regarded as promising materials as anodes for potassium-ion batteries(PlBs).Building amorphous structure and introduci...Owing to adjustable microstructure and stable physiochemical properties,carbon-based materials are regarded as promising materials as anodes for potassium-ion batteries(PlBs).Building amorphous structure and introducing defects are favorable methods to generate active sites and improve the electrochemical performances of carbon-based materials.In this work,we develop a facile carbonization method to prepare sulfur-doped amorphous carbon microspheres with hierarchical structure and modulated defects concentration(S-CM-700) for potassium storage.Benefiting from the special microstructure,S-CM-700 exhibits the optimal performance and obtains high reversible capacity of 199.6 mAh·g^(-1) at 100 mA·g^(-1),excellent rate property and prominent durability(0.0055%capacity decay per cycle during 1800 cycles).Kinetics analysis and electrochemical characterization are carried out to reveal that the potassium storage could be boosted by regulating the defect level,layer spacing and the content of sulfur-doping.The work provides a general synthesis approach to prepare sustainable carbon anodes for advanced PlBs.展开更多
The diamond-like compound Cu_(3)PSe_(4)with low lattice thermal conductivity is deemed to be a promising thermoelectric material,which can directly convert waste heat into electricity or vice versa with no moving part...The diamond-like compound Cu_(3)PSe_(4)with low lattice thermal conductivity is deemed to be a promising thermoelectric material,which can directly convert waste heat into electricity or vice versa with no moving parts and greenhouse emissions.However,its performance is limited by its low electrical conductivity.In this study,we report an effective method to enhance thermoelectric performance of Cu_(3)PSe_(4)by defect engineering.It is found that the carrier concentrations of Cu_(3-x)PSe_(4)(x=0,0.03,0.06,0.09,0.12)compounds are increased by two orders of magnitude as x>0.03,from 1×10^(17)to 1×10^(19)cm^(-3).Combined with the intrinsically low lattice thermal conductivities and enhanced electrical transport performance,a maximum zT value of 0.62 is obtained at 727 K for x=0.12 sample,revealing that Cu defect regulation can be an effective method for enhancing thermoelectric performance of Cu_(3)PSe_(4).展开更多
BiTe is a potentially attractive candidate for thermoelectric applications because it is the structural analogue of the state-of-the-art thermoelectric material,bismuth telluride(Bi_(2)Te_(3)). However, BiTe has attra...BiTe is a potentially attractive candidate for thermoelectric applications because it is the structural analogue of the state-of-the-art thermoelectric material,bismuth telluride(Bi_(2)Te_(3)). However, BiTe has attracted little attention due to its small band gap and high electron concentration. In this study, remarkable increase in thermoelectric performance in the n-type Bi_(1-x)Sb_(x)Te compounds through tuning the carrier concentration with chemical doping is shown. The Seebeck coefficient of Bi_(1-x)Sb_(x)Te increases remarkably while the electronic thermal conductivity decreases gradually as Sb content is increased, leading to enhanced thermoelectric figure of merit(ZT). Moreover, the simultaneous optimization of the electrical and thermal transport properties leads the peak temperature of the figure of merit to shift toward lower temperature with Sb content increasing in Bi_(1-x)Sb_(x)Te, thus making Bi_(1-x)Sb_(x)Te a potential alternative to bismuth telluride for near-room-temperature thermoelectric applications. In addition, the presence of multiple low-frequency optical phonons and their coupling with the long-wavelength heat carrying acoustic phonons in all the Bi_(1-x)Sb_(x)Te investigated are revealed based on the combined Debye-Einstein model. The present results provide the underlying mechanism connecting thermoelectric performance and lattice dynamics in Bi_(1-x)Sb_(x)Te compounds.展开更多
The thermoelectric transport properties of Zr0.43Hf0.57 NiSn half-Heusler compounds were investigated for samples sintered with different spark plasma sintering(SPS)periods:8,32 and 72 min.By means of scanning transmi...The thermoelectric transport properties of Zr0.43Hf0.57 NiSn half-Heusler compounds were investigated for samples sintered with different spark plasma sintering(SPS)periods:8,32 and 72 min.By means of scanning transmission electron microscopy with a highangular annular dark-field detector(STEM-HAADF),it was found that sintering time affected the defect concentration,namely the amount of Ni interstitial atoms,and created locally ordered inclusions of full-Heusler phase.The structural information,phase composition and electrical transport properties could be consistently explained by the assumption that Ni interstitials give rise to an impurity band situated about 100 meV below the bottom of the conduction band via a self-doping behavior.The impurity band was found to merge with the conduction band for the sample with intermediate SPS time.The effect was ascribed to the gradual dissolution of full-Heusler phase inclusions and production of interstitial Ni defects,which eventually vanished for the sample with the longest sintering time.It was demonstrated that the modification of the density of states near the edge of the conduction band and enhanced overall charge carrier concentration provided by defect engineering led to overall 26%increase in the thermoelectric figure of merit(ZT)with respect to the other samples.展开更多
With the quick development of sustainable energy sources, aqueous zinc-ion batteries(AZIBs) have become a highly potential energy storage technology. It is a crucial step to construct desired electrode materials for i...With the quick development of sustainable energy sources, aqueous zinc-ion batteries(AZIBs) have become a highly potential energy storage technology. It is a crucial step to construct desired electrode materials for improving the total performance of AZIBs. In recent years, considerable efforts have focused on the modification of vanadium-based cathode materials. In this review, we summarized defect engineering strategies of vanadium-based cathodes, including oxygen defects, cation vacancies and heterogeneous doping. Then, we discussed the effect of various defects on the electrochemical performance of electrode materials. Finally, we proposed the future challenges and development directions of V-based cathode materials.展开更多
MoS_(2) is a promising anode material in sodium-ion battery technologies for possessing high theoretical capacity.However,the sluggish Na^(+) diffusion kinetics and low electronic conductivity hinder the promises.Here...MoS_(2) is a promising anode material in sodium-ion battery technologies for possessing high theoretical capacity.However,the sluggish Na^(+) diffusion kinetics and low electronic conductivity hinder the promises.Herein,a unique MoS_(2)/FeS_(2)/C heterojunction with abundant defects and hollow structure(MFCHHS)was constructed.The synergy of defect engineering in MoS_(2),FeS_(2),and the carbon layer of MFCHHS with a larger specific surface area provides multiple storage sites of Na^(+)corresponding to the surface-controlled process.The MoS_(2)/FeS_(2)/C heterostructure and rich defects in MoS_(2) and carbon layer lower the Na^(+) diffusion energy barrier.Additionally,the construction of MoS_(2)/FeS_(2) heterojunction promotes electron transfer at the interface,accompanying with excellent conductivity of the carbon layer to facilitate reversible electrochemical reactions.The abundant defects and mismatches at the interface of MoS_(2)/FeS_(2) and MoS_(2)/C heterojunctions could relieve lattice stress and volume change sequentially.As a result,the MFCHHS anode exhibits the high capacity of 613.1 mA h g^(-1)at 0.5 A g^(-1) and 306.1 mA h g^(-1) at 20 A g^(-1).The capacity retention of 85.0%after 1400 cycles at 5.0 A g^(-1) is achieved.The density functional theory(DFT)calculation and in situ transmission electron microscope(TEM),Raman,ex-situ X-ray photon spectroscopy(XPS)studies confirm the low volume change during intercalation/deintercalation process and the efficient Na^(+)storage in the layered structure of MoS_(2) and carbon layer,as well as the defects and heterostructures in MFCHHS.We believe this work could provide an inspiration for constructing heterojunction with abundant defects to foster fast electron and Na^(+) diffusion kinetics,resulting in excellent rate capability and cycling stability.展开更多
Electrocatalytic carbon dioxide(CO_(2))reduction is an important way to achieve carbon neutrality by converting CO_(2)in-to high-value-added chemicals using electric energy.Carbon-based materials are widely used in va...Electrocatalytic carbon dioxide(CO_(2))reduction is an important way to achieve carbon neutrality by converting CO_(2)in-to high-value-added chemicals using electric energy.Carbon-based materials are widely used in various electrochemical reactions,including electrocatalytic CO_(2)reduction,due to their low cost and high activity.In recent years,defect engineering has attracted wide attention by constructing asymmetric defect centers in the materials,which can optimize the physicochemical properties of the mater-ial and improve its electrocatalytic activity.This review summarizes the types,methods of formation and defect characterization tech-niques of defective carbon-based materials.The advantages of defect engineering and the advantages and disadvantages of various defect formation methods and characterization techniques are also evaluated.Finally,the challenges of using defective carbon-based materials in electrocatalytic CO_(2)reduction are investigated and opportunities for their use are discussed.It is believed that this re-view will provide suggestions and guidance for developing defective carbon-based materials for CO_(2)reduction.展开更多
Heavy-metal-free ternary Cu–In–Se quantum dots(CISe QDs)are promising for solar fuel production because of their low toxicity,tunable band gap,and high light absorption coefficient.Although defects significantly aff...Heavy-metal-free ternary Cu–In–Se quantum dots(CISe QDs)are promising for solar fuel production because of their low toxicity,tunable band gap,and high light absorption coefficient.Although defects significantly affect the photophysical properties of QDs,the influence on photoelectrochemical hydrogen production is not well understood.Herein,we present the defect engineering of CISe QDs for efficient solar-energy conversion.Lewis acid–base reactions between metal halide–oleylamine complexes and oleylammonium selenocarbamate are modulated to achieve CISe QDs with the controlled amount of Cu vacancies without changing their morphology.Among them,CISe QDs with In/Cu=1.55 show the most outstanding photoelectrochemical hydrogen generation with excellent photocurrent density of up to 10.7 mA cm-2(at 0.6 VRHE),attributed to the suitable electronic band structures and enhanced carrier concentrations/lifetimes of the QDs.The proposed method,which can effectively control the defects in heavy-metal-free ternary QDs,offers a deeper understanding of the effects of the defects and provides a practical approach to enhance photoelectrochemical hydrogen generation.展开更多
Vanadium redox flow batteries(VRFBs)are one of the most promising energy storage systems owing to their safety,efficiency,flexibility and scalability.However,the commercial viability of VRFBs is still hindered by the ...Vanadium redox flow batteries(VRFBs)are one of the most promising energy storage systems owing to their safety,efficiency,flexibility and scalability.However,the commercial viability of VRFBs is still hindered by the low electrochemical performance of the available carbon-based electrodes.Defect engineering is a powerful strategy to enhance the redox catalytic activity of carbon-based electrodes for VRFBs.In this paper,uniform carbon defects are introduced on the surfaces of carbon felt(CF)electrode by Ar plasma etching.Together with a higher specific surface area,the Ar plasma treated CF offers additional catalytic sites,allowing faster and more reversible oxidation/reduction reactions of vanadium ions.As a result,the VRFB using plasma treated electrode shows a power density of 1018.3 mW/cm^(2),an energy efficiency(EE)of 84.5%,and the EE remains stable over 1000 cycles.展开更多
Owing to the intrinsically sluggish kinetics of urea oxidation reaction(UOR)involving a six-electron transfer process,developing efficient UOR electrocatalyst is a great challenge remained to be overwhelmed.Herein,by ...Owing to the intrinsically sluggish kinetics of urea oxidation reaction(UOR)involving a six-electron transfer process,developing efficient UOR electrocatalyst is a great challenge remained to be overwhelmed.Herein,by taking advantage of 2-Methylimidazole,of which is a kind of alkali in water and owns strong coordination ability to Co^(2+)in methanol,trace Co(1.0 mol%)addition was found to induce defect engineering onα-Ni(OH)_(2)in a dual-solvent system of water and methanol.Physical characterization results revealed that the synthesized electrocatalyst(WM-Ni_(0.99)Co_(0.01)(OH)_(2))was a kind of defective nanosheet with thickness around 5-6 nm,attributing to the synergistic effect of Co doping and defect engineering,its electron structure was finely altered,and its specific surface a rea was tremendously enlarged from 68 to 172.3 m^(2)g^(-1).With all these merits,its overpotential to drive 10 mA cm^(-2)was reduced by 110 mV.Besides,the interfacial behavior of UOR was also well deciphered by operando electrochemical impedance spectroscopy.展开更多
Electrocatalytic water splitting seems to be an efficient strategy to deal with increasingly serious environmental problems and energy crises but still suffers from the lack of stable and efficient electrocatalysts.De...Electrocatalytic water splitting seems to be an efficient strategy to deal with increasingly serious environmental problems and energy crises but still suffers from the lack of stable and efficient electrocatalysts.Designing practical electrocatalysts by introducing defect engineering,such as hybrid structure,surface vacancies,functional modification,and structural distortions,is proven to be a dependable solution for fabricating electrocatalysts with high catalytic activities,robust stability,and good practicability.This review is an overview of some relevant reports about the effects of defect engineering on the electrocatalytic water splitting performance of electrocatalysts.In detail,the types of defects,the preparation and characterization methods,and catalytic performances of electrocatalysts are presented,emphasizing the effects of the introduced defects on the electronic structures of electrocatalysts and the optimization of the intermediates'adsorption energy throughout the review.Finally,the existing challenges and personal perspectives of possible strategies for enhancing the catalytic performances of electrocatalysts are proposed.An in-depth understanding of the effects of defect engineering on the catalytic performance of electrocatalysts will light the way to design high-efficiency electrocatalysts for water splitting and other possible applications.展开更多
The lithium polysulfide shuttle and sluggish sulfur reaction kinetics still pose significant challenges to lithium-sulfur(Li-S)batteries.The functional plane of Fe-MoSe_(2)@r GO nanohybrid with abundant defects has be...The lithium polysulfide shuttle and sluggish sulfur reaction kinetics still pose significant challenges to lithium-sulfur(Li-S)batteries.The functional plane of Fe-MoSe_(2)@r GO nanohybrid with abundant defects has been designed and applied in Li-S batteries to develop the functional separator and multi-layer sulfur cathode.The cell with a functional separator exhibits a retention capacity of 462 m Ah g^(-1)after the 1000th at 0.5 C and 516 m Ah g^(-1)after the 600th at 0.3 C.Even at low electrolyte conditions(7.0μL_(mgsulfur)^(-1)and 15μL_(mgsulfur)^(-1))under high sulfur loadings(3.46 mg cm^(-2)and 3.73 mg cm^(-2)),the cell still presents high reversible discharge capacities 679 and 762 m Ah g^(-1)after 70 cycles,respectively.Further,at sulfur loadings up to 8.26 and 5.2 mg cm^(-2),the cells assembled with the bi-layers sulfur cathode and the tri-layers sulfur cathode give reversible capacities of 3.3 m Ah cm^(-2)after the 100th cycle and 3.0 m Ah cm^(-2)after the 120th cycle,respectively.This research not only demonstrates that the FeMoSe_(2)@r GO functional plane is successfully designed and applied in Li-S batteries with superior electrochemical performances but also paves the novel way for developing a unique multi-layer cathode technique to enhance and advance the electrochemical behavior of Li-S cells at a high-sulfur-loading cathode under lean electrolyte/sulfur(E/S)ratio.展开更多
Crystal defect engineering is widely used as an effective approach to regulate the optical and optoelectronic properties of semiconductor nanostructures.However,photogenerated electron-hole pair recombination centers ...Crystal defect engineering is widely used as an effective approach to regulate the optical and optoelectronic properties of semiconductor nanostructures.However,photogenerated electron-hole pair recombination centers caused by structural defects usually lead to the reduction of optoelectronic performance.In this work,a high-performance photodetector based on(GaN)_(1-x)(ZnO)_(x)solid solution nanowire with bicrystal structure is fabricated and it shows excellent photoresponse to ultraviolet and visible light.The highest responsivity of the photodetector is as high as 60,86 and 43 A/W under the irradiation of365 nm,532 nm and 650 nm,respectively.The corresponding response time is as fast as 170,320 and 160 ms.Such wide spectral responses can be attributed to various intermediate energy levels induced by the introduction of various structural defects and dopants in the solid solution nanowire.Moreover,the peculiar bicrystal boundary along the axial direction of the nanowire provides two parallel and fast transmission channels for photo-generated carriers,reducing the recombination of photo-generated carriers.Our findings provide a valued example using crystal defect engineering to broaden the photoresponse range and improve the photodetector performance and thus can be extended to other material systems for various optoelectronic applications.展开更多
Although defect engineering opens up new opportunities in the field of gas sensors,the introduction of defects to enhance the gas sensing properties of metal oxide semiconductors(MOSs)has long been neglected.In this r...Although defect engineering opens up new opportunities in the field of gas sensors,the introduction of defects to enhance the gas sensing properties of metal oxide semiconductors(MOSs)has long been neglected.In this review,defect engineering strategies have been systematically introduced,with a focus on employing them for improved gas sensing performances.To keep the subject focused,we take SnO_(2) nanomaterials as an example.Various synthesis methods for defective SnO_(2),including ion/electron/ray/laser-beam irradiation,plasma treatment,heating protocol,chemical reduction,tailoring specially exposed crystal facets and atoms doping,are emphasized.Different roles of defects on the gas sensing process of SnO_(2) are discussed.Finally,critical issues and future directions of defect engineering are presented.This paper provides a platform for better understanding the relationships between synthesis,defect types and gas sensing performances of MOSs.It is also expected to unpack an important research direction for controlled synthesis of defective nanomaterials with other applications,including advanced energy conversion and storage.展开更多
基金supported by The National Key R&D Program of China(No.2021YFB3500700)National Natural Science Foundation of China(Nos.21677010 and 51808037)Special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04)。
文摘Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modification methods.Constructing defects on the surface of catalytic materials can effectively modulate the coordination environment of the active sites,affecting and changing the electrons,geometry,and other important properties at the catalytic active sites,thus altering the catalytic activity of the catalysts.However,the conformational relationship between defects and catalytic activity remains to be clarified.This dissertation focuses on an overview of recent advances in defect engineering in environmental catalysis.Based on defining the classification of defects in catalytic materials,defect construction methods,and characterization techniques are summarized and discussed.Focusing on an overview of the characteristics of the role of defects in electrocatalytic,photocatalytic,and thermal catalytic reactions and the mechanism of catalytic reactions.An elaborate link is given between the reaction activity and the structure of catalyst defects.Finally,the existing challenges and possible future directions for the application of defect engineering in environmental catalysis are discussed,which are expected to guide the design and development of efficient environmental catalysts and mechanism studies.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272103 and 52072010)Beijing Natural Science Foundation(Grant Nos.2242029 and JL23004).
文摘High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.
基金support of the National Natural Science Foundation of China(Grant No.22225801,22178217 and 22308216)supported by the Fundamental Research Funds for the Central Universities,conducted at Tongji University.
文摘Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.
基金supported by the National Natural Science Foundation of China(U21A20281)the Special Fund for Young Teachers from Zhengzhou University(JC23557030,JC23257011)+1 种基金the Key Research Projects of Higher Education Institutions of Henan Province(24A530009)the Project of Zhongyuan Critical Metals Laboratory(GJJSGFYQ202336).
文摘Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20231342,BK20210867)National Natural Science Foundation of China(22008163)+1 种基金Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment(SKLPEE–KF202309)Natural Science Research Project of Higher Education Institutions in Jiangsu Province(21KJB150038).
文摘Hydrogen peroxide(H_(2)O_(2))photosynthesis represents an advanced on-site production method with significant potential for on-demand supply.However,various challenges hinder the efficiency of H_(2)O_(2) yield,including weak oxygen adsorption capacity,reliance on sacrificial agents,low charge separation and transfer efficiency.In this regard,doping design and defect engineering have emerged as robust and effective strategies for catalyst modification,particularly through their synergistic effects.Additionally,advanced in situ characterization techniques for investigating reaction mechanisms are gaining momentum.Herein,this review provides a comprehensive analysis of the fundamentals and challenges associated with photocatalytic H_(2)O_(2) production,and highlights the advantages of doping and defect engineering.Subsequently,it outlines preparation methods and applications of these strategies.More importantly,it emphasizes the advanced characterization techniques utilized to validate doping and defects,as well as to investigate underlying mechanisms.Finally,the potential prospects and challenges of this reaction are anticipated.This review aims to offer valuable insights for researchers from both experimental and theoretical perspectives.
基金the National Natural Science Foundation of China(52062012)Key Science&Technology Project of Hainan Province(ZDYF2020028)+2 种基金Key-Area Research and Development Program of Guangdong Province(2019B1102109003)the Innovation Team of Universities of Guangdong Province(2020KCXTD011)Guangdong Province Key Discipline Construction Project(2021ZDJS102).
文摘Sustainable energy conversion and storage technologies are a vital prerequisite for neutral future carbon.To this end,carbon materials with attractive features,such as tunable pore architecture,good electrical conductivity,outstanding physicochemical stability,abundant resource,and low cost,have used as promising electrode materials for energy conversion and storage.Defect engineering could modulate the structures of carbon materials,thereby affecting their electronic properties.The presence of defects on carbons may lead to asymmetric charge distribution,change in geometrical configuration,and distortion of the electronic structure that may result in unexpected electrochemical performances.In this review,recent advances in defects of carbons used for energy conversion and storage were examined in terms of types,regulation strategies,and fine characterization means of defects.The applications of such carbons in supercapacitors,rechargeable batteries,and electrocatalysis were also discussed.The perspectives toward the development of defect engineering carbons were proposed.In all,novel insights related to improvement in high-performance carbon materials for future energy conversion and storage applications were provided.
基金financially supported by the National Natural Science Foundation of China (No.51904216)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing (No.WUT:2022-KF-4)the National Innovation Training Program for College Students (No. 312040000254)。
文摘Owing to adjustable microstructure and stable physiochemical properties,carbon-based materials are regarded as promising materials as anodes for potassium-ion batteries(PlBs).Building amorphous structure and introducing defects are favorable methods to generate active sites and improve the electrochemical performances of carbon-based materials.In this work,we develop a facile carbonization method to prepare sulfur-doped amorphous carbon microspheres with hierarchical structure and modulated defects concentration(S-CM-700) for potassium storage.Benefiting from the special microstructure,S-CM-700 exhibits the optimal performance and obtains high reversible capacity of 199.6 mAh·g^(-1) at 100 mA·g^(-1),excellent rate property and prominent durability(0.0055%capacity decay per cycle during 1800 cycles).Kinetics analysis and electrochemical characterization are carried out to reveal that the potassium storage could be boosted by regulating the defect level,layer spacing and the content of sulfur-doping.The work provides a general synthesis approach to prepare sustainable carbon anodes for advanced PlBs.
基金the Graduate Scientific Research and Innovation Foundation of Chongqing,China(No.CYB 19064)the Project for Fundamental and Frontier Research in Chongqing(No.CSTC2017JCYJAX0388)+2 种基金Shenzhen Science and Technology Innovation Committee(No.JCYJ20170818155752559)the National Natural Science Foundation of China(Nos.51772035,11674040 and 51472036)the Fundamental Research Funds for the Central Universities(No.106112017CDJQJ308821)。
文摘The diamond-like compound Cu_(3)PSe_(4)with low lattice thermal conductivity is deemed to be a promising thermoelectric material,which can directly convert waste heat into electricity or vice versa with no moving parts and greenhouse emissions.However,its performance is limited by its low electrical conductivity.In this study,we report an effective method to enhance thermoelectric performance of Cu_(3)PSe_(4)by defect engineering.It is found that the carrier concentrations of Cu_(3-x)PSe_(4)(x=0,0.03,0.06,0.09,0.12)compounds are increased by two orders of magnitude as x>0.03,from 1×10^(17)to 1×10^(19)cm^(-3).Combined with the intrinsically low lattice thermal conductivities and enhanced electrical transport performance,a maximum zT value of 0.62 is obtained at 727 K for x=0.12 sample,revealing that Cu defect regulation can be an effective method for enhancing thermoelectric performance of Cu_(3)PSe_(4).
基金financially supported by the National Key R&D Program of China(Nos.2018YFB0703602 and 2017YFA0303500)the National Natural Science Foundation of China(Nos.21622107 and U1832142)+2 种基金the Youth Innovation Promotion Association CAS(No.2016392)the Fundamental Research Funds for the Central University(No.WK2340000094)the Key Research Program of Frontier Sciences(No.QYZDY-SSW-SLH011)。
文摘BiTe is a potentially attractive candidate for thermoelectric applications because it is the structural analogue of the state-of-the-art thermoelectric material,bismuth telluride(Bi_(2)Te_(3)). However, BiTe has attracted little attention due to its small band gap and high electron concentration. In this study, remarkable increase in thermoelectric performance in the n-type Bi_(1-x)Sb_(x)Te compounds through tuning the carrier concentration with chemical doping is shown. The Seebeck coefficient of Bi_(1-x)Sb_(x)Te increases remarkably while the electronic thermal conductivity decreases gradually as Sb content is increased, leading to enhanced thermoelectric figure of merit(ZT). Moreover, the simultaneous optimization of the electrical and thermal transport properties leads the peak temperature of the figure of merit to shift toward lower temperature with Sb content increasing in Bi_(1-x)Sb_(x)Te, thus making Bi_(1-x)Sb_(x)Te a potential alternative to bismuth telluride for near-room-temperature thermoelectric applications. In addition, the presence of multiple low-frequency optical phonons and their coupling with the long-wavelength heat carrying acoustic phonons in all the Bi_(1-x)Sb_(x)Te investigated are revealed based on the combined Debye-Einstein model. The present results provide the underlying mechanism connecting thermoelectric performance and lattice dynamics in Bi_(1-x)Sb_(x)Te compounds.
基金financially supported by German Research Foundation Priority Programme 1386(No.WE 2803/2-2)the European Union under Marie Sklodowska-Curie Program(W.J.X.)。
文摘The thermoelectric transport properties of Zr0.43Hf0.57 NiSn half-Heusler compounds were investigated for samples sintered with different spark plasma sintering(SPS)periods:8,32 and 72 min.By means of scanning transmission electron microscopy with a highangular annular dark-field detector(STEM-HAADF),it was found that sintering time affected the defect concentration,namely the amount of Ni interstitial atoms,and created locally ordered inclusions of full-Heusler phase.The structural information,phase composition and electrical transport properties could be consistently explained by the assumption that Ni interstitials give rise to an impurity band situated about 100 meV below the bottom of the conduction band via a self-doping behavior.The impurity band was found to merge with the conduction band for the sample with intermediate SPS time.The effect was ascribed to the gradual dissolution of full-Heusler phase inclusions and production of interstitial Ni defects,which eventually vanished for the sample with the longest sintering time.It was demonstrated that the modification of the density of states near the edge of the conduction band and enhanced overall charge carrier concentration provided by defect engineering led to overall 26%increase in the thermoelectric figure of merit(ZT)with respect to the other samples.
基金supported by National Natural Science Foundation of China (No. 52172218)。
文摘With the quick development of sustainable energy sources, aqueous zinc-ion batteries(AZIBs) have become a highly potential energy storage technology. It is a crucial step to construct desired electrode materials for improving the total performance of AZIBs. In recent years, considerable efforts have focused on the modification of vanadium-based cathode materials. In this review, we summarized defect engineering strategies of vanadium-based cathodes, including oxygen defects, cation vacancies and heterogeneous doping. Then, we discussed the effect of various defects on the electrochemical performance of electrode materials. Finally, we proposed the future challenges and development directions of V-based cathode materials.
基金the National Natural Science Foundation of China(NSFC)(22105059,22279112)the Talent Introduction Program of Hebei Agricultural University(YJ201810)+5 种基金the Youth Topnotch Talent Foundation of Hebei Provincial Universities(BJK2022023)the Natural Science Foundation of Hebei Province(B2022203018)the Fok Ying-Tong Education Foundation of China(171064)the Natural Science Foundation of Shandong Province,China(ZR2021QE192)the China Postdoctoral Science Foundation(2018M630747)the 333 Talent Program of Hebei Province(C20221018)for their support。
文摘MoS_(2) is a promising anode material in sodium-ion battery technologies for possessing high theoretical capacity.However,the sluggish Na^(+) diffusion kinetics and low electronic conductivity hinder the promises.Herein,a unique MoS_(2)/FeS_(2)/C heterojunction with abundant defects and hollow structure(MFCHHS)was constructed.The synergy of defect engineering in MoS_(2),FeS_(2),and the carbon layer of MFCHHS with a larger specific surface area provides multiple storage sites of Na^(+)corresponding to the surface-controlled process.The MoS_(2)/FeS_(2)/C heterostructure and rich defects in MoS_(2) and carbon layer lower the Na^(+) diffusion energy barrier.Additionally,the construction of MoS_(2)/FeS_(2) heterojunction promotes electron transfer at the interface,accompanying with excellent conductivity of the carbon layer to facilitate reversible electrochemical reactions.The abundant defects and mismatches at the interface of MoS_(2)/FeS_(2) and MoS_(2)/C heterojunctions could relieve lattice stress and volume change sequentially.As a result,the MFCHHS anode exhibits the high capacity of 613.1 mA h g^(-1)at 0.5 A g^(-1) and 306.1 mA h g^(-1) at 20 A g^(-1).The capacity retention of 85.0%after 1400 cycles at 5.0 A g^(-1) is achieved.The density functional theory(DFT)calculation and in situ transmission electron microscope(TEM),Raman,ex-situ X-ray photon spectroscopy(XPS)studies confirm the low volume change during intercalation/deintercalation process and the efficient Na^(+)storage in the layered structure of MoS_(2) and carbon layer,as well as the defects and heterostructures in MFCHHS.We believe this work could provide an inspiration for constructing heterojunction with abundant defects to foster fast electron and Na^(+) diffusion kinetics,resulting in excellent rate capability and cycling stability.
文摘Electrocatalytic carbon dioxide(CO_(2))reduction is an important way to achieve carbon neutrality by converting CO_(2)in-to high-value-added chemicals using electric energy.Carbon-based materials are widely used in various electrochemical reactions,including electrocatalytic CO_(2)reduction,due to their low cost and high activity.In recent years,defect engineering has attracted wide attention by constructing asymmetric defect centers in the materials,which can optimize the physicochemical properties of the mater-ial and improve its electrocatalytic activity.This review summarizes the types,methods of formation and defect characterization tech-niques of defective carbon-based materials.The advantages of defect engineering and the advantages and disadvantages of various defect formation methods and characterization techniques are also evaluated.Finally,the challenges of using defective carbon-based materials in electrocatalytic CO_(2)reduction are investigated and opportunities for their use are discussed.It is believed that this re-view will provide suggestions and guidance for developing defective carbon-based materials for CO_(2)reduction.
基金the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(grant nos.2021R1C1C1007844,2021M3I3A1085039,2020R1F1A1061505,and 2020R1C1C1012014).
文摘Heavy-metal-free ternary Cu–In–Se quantum dots(CISe QDs)are promising for solar fuel production because of their low toxicity,tunable band gap,and high light absorption coefficient.Although defects significantly affect the photophysical properties of QDs,the influence on photoelectrochemical hydrogen production is not well understood.Herein,we present the defect engineering of CISe QDs for efficient solar-energy conversion.Lewis acid–base reactions between metal halide–oleylamine complexes and oleylammonium selenocarbamate are modulated to achieve CISe QDs with the controlled amount of Cu vacancies without changing their morphology.Among them,CISe QDs with In/Cu=1.55 show the most outstanding photoelectrochemical hydrogen generation with excellent photocurrent density of up to 10.7 mA cm-2(at 0.6 VRHE),attributed to the suitable electronic band structures and enhanced carrier concentrations/lifetimes of the QDs.The proposed method,which can effectively control the defects in heavy-metal-free ternary QDs,offers a deeper understanding of the effects of the defects and provides a practical approach to enhance photoelectrochemical hydrogen generation.
基金Project(Xiang Zu [2016] 91) supported by the “100 Talented Teams” of Hunan Province,ChinaProject(2018RS3077) supported by the Huxiang High-level Talents Program,China+2 种基金Project(22002009) supported by the National Natural Science Foundation of ChinaProject(2021JJ40565) supported by the Natural Science Foundation of Hunan Province,ChinaProject(19C0054) supported by the Scientific Research Foundation of Hunan Provincial Education Department,China。
文摘Vanadium redox flow batteries(VRFBs)are one of the most promising energy storage systems owing to their safety,efficiency,flexibility and scalability.However,the commercial viability of VRFBs is still hindered by the low electrochemical performance of the available carbon-based electrodes.Defect engineering is a powerful strategy to enhance the redox catalytic activity of carbon-based electrodes for VRFBs.In this paper,uniform carbon defects are introduced on the surfaces of carbon felt(CF)electrode by Ar plasma etching.Together with a higher specific surface area,the Ar plasma treated CF offers additional catalytic sites,allowing faster and more reversible oxidation/reduction reactions of vanadium ions.As a result,the VRFB using plasma treated electrode shows a power density of 1018.3 mW/cm^(2),an energy efficiency(EE)of 84.5%,and the EE remains stable over 1000 cycles.
基金supported by the Central South University Scientific Research Foundation for Post-doctor(Grant No.:140050052)the National Natural Science Foundation of China(Grant No.:52204325)
文摘Owing to the intrinsically sluggish kinetics of urea oxidation reaction(UOR)involving a six-electron transfer process,developing efficient UOR electrocatalyst is a great challenge remained to be overwhelmed.Herein,by taking advantage of 2-Methylimidazole,of which is a kind of alkali in water and owns strong coordination ability to Co^(2+)in methanol,trace Co(1.0 mol%)addition was found to induce defect engineering onα-Ni(OH)_(2)in a dual-solvent system of water and methanol.Physical characterization results revealed that the synthesized electrocatalyst(WM-Ni_(0.99)Co_(0.01)(OH)_(2))was a kind of defective nanosheet with thickness around 5-6 nm,attributing to the synergistic effect of Co doping and defect engineering,its electron structure was finely altered,and its specific surface a rea was tremendously enlarged from 68 to 172.3 m^(2)g^(-1).With all these merits,its overpotential to drive 10 mA cm^(-2)was reduced by 110 mV.Besides,the interfacial behavior of UOR was also well deciphered by operando electrochemical impedance spectroscopy.
基金National Natural Science Foundation of China,Grant/Award Number:52271200Scientific and Technological Innovation Foundation of Foshan,Grant/Award Number:BK20BE009+1 种基金the Fundamental Research Funds for the Central Universities,Grant/Award Number:FRF-TP-18-079A1Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2020A1515110460,ORCID:http://orcid.org/0000-0002-0870-2248。
文摘Electrocatalytic water splitting seems to be an efficient strategy to deal with increasingly serious environmental problems and energy crises but still suffers from the lack of stable and efficient electrocatalysts.Designing practical electrocatalysts by introducing defect engineering,such as hybrid structure,surface vacancies,functional modification,and structural distortions,is proven to be a dependable solution for fabricating electrocatalysts with high catalytic activities,robust stability,and good practicability.This review is an overview of some relevant reports about the effects of defect engineering on the electrocatalytic water splitting performance of electrocatalysts.In detail,the types of defects,the preparation and characterization methods,and catalytic performances of electrocatalysts are presented,emphasizing the effects of the introduced defects on the electronic structures of electrocatalysts and the optimization of the intermediates'adsorption energy throughout the review.Finally,the existing challenges and personal perspectives of possible strategies for enhancing the catalytic performances of electrocatalysts are proposed.An in-depth understanding of the effects of defect engineering on the catalytic performance of electrocatalysts will light the way to design high-efficiency electrocatalysts for water splitting and other possible applications.
基金the support from the National Natural Science Foundation of China(No.21373189)the Science and Technology Department of Henan Province(No.212102210586)the Top-Notch Talents Program of Henan Agricultural University(No.30501035)。
文摘The lithium polysulfide shuttle and sluggish sulfur reaction kinetics still pose significant challenges to lithium-sulfur(Li-S)batteries.The functional plane of Fe-MoSe_(2)@r GO nanohybrid with abundant defects has been designed and applied in Li-S batteries to develop the functional separator and multi-layer sulfur cathode.The cell with a functional separator exhibits a retention capacity of 462 m Ah g^(-1)after the 1000th at 0.5 C and 516 m Ah g^(-1)after the 600th at 0.3 C.Even at low electrolyte conditions(7.0μL_(mgsulfur)^(-1)and 15μL_(mgsulfur)^(-1))under high sulfur loadings(3.46 mg cm^(-2)and 3.73 mg cm^(-2)),the cell still presents high reversible discharge capacities 679 and 762 m Ah g^(-1)after 70 cycles,respectively.Further,at sulfur loadings up to 8.26 and 5.2 mg cm^(-2),the cells assembled with the bi-layers sulfur cathode and the tri-layers sulfur cathode give reversible capacities of 3.3 m Ah cm^(-2)after the 100th cycle and 3.0 m Ah cm^(-2)after the 120th cycle,respectively.This research not only demonstrates that the FeMoSe_(2)@r GO functional plane is successfully designed and applied in Li-S batteries with superior electrochemical performances but also paves the novel way for developing a unique multi-layer cathode technique to enhance and advance the electrochemical behavior of Li-S cells at a high-sulfur-loading cathode under lean electrolyte/sulfur(E/S)ratio.
基金partially supported by the National Natural Science Foundation of China(Nos.51702326 and 51872296)the Liaoning Province Natural Science Foundation(No.2019-MS333)+3 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2019197)the Shenyang National Laboratory for Materials Science(No.L2019F36)the Shenyang Planning Project of Science and Technology(No.18-013-0-52)Tomsk Polytechnic University Competitiveness Enhancement Program grant with project number TPU CEP NOC N.M.Kizhnera188/2020。
文摘Crystal defect engineering is widely used as an effective approach to regulate the optical and optoelectronic properties of semiconductor nanostructures.However,photogenerated electron-hole pair recombination centers caused by structural defects usually lead to the reduction of optoelectronic performance.In this work,a high-performance photodetector based on(GaN)_(1-x)(ZnO)_(x)solid solution nanowire with bicrystal structure is fabricated and it shows excellent photoresponse to ultraviolet and visible light.The highest responsivity of the photodetector is as high as 60,86 and 43 A/W under the irradiation of365 nm,532 nm and 650 nm,respectively.The corresponding response time is as fast as 170,320 and 160 ms.Such wide spectral responses can be attributed to various intermediate energy levels induced by the introduction of various structural defects and dopants in the solid solution nanowire.Moreover,the peculiar bicrystal boundary along the axial direction of the nanowire provides two parallel and fast transmission channels for photo-generated carriers,reducing the recombination of photo-generated carriers.Our findings provide a valued example using crystal defect engineering to broaden the photoresponse range and improve the photodetector performance and thus can be extended to other material systems for various optoelectronic applications.
基金supported by the National Natural Science Foundation of China(No.51872173)the Taishan Scholars Program of Shandong Province,China(No.tsqn201812068)+3 种基金the Opening Fund of State Key Laboratory of Heavy Oil Processing,China(No.SKLOP202002006)the Higher School Youth Innovation Team of Shandong Province,China(No.2019KJA013)the Science and Technology Special Project of Qingdao City,Shandong Province,China(No.20-3-4-3-nsh)financial support provided by the Natural Science Foundation of Shandong Province,China(No.ZR2021QE092).
文摘Although defect engineering opens up new opportunities in the field of gas sensors,the introduction of defects to enhance the gas sensing properties of metal oxide semiconductors(MOSs)has long been neglected.In this review,defect engineering strategies have been systematically introduced,with a focus on employing them for improved gas sensing performances.To keep the subject focused,we take SnO_(2) nanomaterials as an example.Various synthesis methods for defective SnO_(2),including ion/electron/ray/laser-beam irradiation,plasma treatment,heating protocol,chemical reduction,tailoring specially exposed crystal facets and atoms doping,are emphasized.Different roles of defects on the gas sensing process of SnO_(2) are discussed.Finally,critical issues and future directions of defect engineering are presented.This paper provides a platform for better understanding the relationships between synthesis,defect types and gas sensing performances of MOSs.It is also expected to unpack an important research direction for controlled synthesis of defective nanomaterials with other applications,including advanced energy conversion and storage.
