Solution-processed Cu(In,Ga)Se_(2)(CIGS) solar cells suffer from serious carrier recombination and power conversion efficiency(PCE) loss because of the poor film properties and easy formation of defects.Herein, we pro...Solution-processed Cu(In,Ga)Se_(2)(CIGS) solar cells suffer from serious carrier recombination and power conversion efficiency(PCE) loss because of the poor film properties and easy formation of defects.Herein, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved opencircuit voltage(VOC) of 662 m V and fill factor(FF) of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.展开更多
The development of metal-free carbon catalysts has garnered significant attention as a promising approach to address the challenges of sustainable catalysis,particularly in the replacement of toxic and environmentally...The development of metal-free carbon catalysts has garnered significant attention as a promising approach to address the challenges of sustainable catalysis,particularly in the replacement of toxic and environmentally hazardous mercury-based systems for the coal-based PVC industry.Within a decade of development,the catalytic performance of carbon catalysts has been improved greatly and even shows superiorities over metal catalysts in some cases,which have demonstrated great potential as sustainable alternatives to mercury catalysts.This review provides a comprehensive summary of the recent advancements in carbon catalysts for acetylene hydrochlorination.It encompasses a wide range of aspects,including the identification of active sites from heteroatom doping to intrinsic carbon defects,the various synthetic strategies employed,the reaction and deactivation mechanisms of carbon catalysts,and the current insights into the key challenges that are encountered on the journey from laboratory research to scalable commercialization within the field of carbon catalysts.The review offers foundational insights and practical guidelines for designing green carbon catalysts systems,not only for acetylene hydrochlorination but also for other heterogeneous catalytic reactions.展开更多
Kirkendall voids(KVs)at the Cu/Sn interface are a typical failure in integrated circuits,leading to solder joint cracking and electrical disconnection.Although the formation of KVs has been attributed to the differenc...Kirkendall voids(KVs)at the Cu/Sn interface are a typical failure in integrated circuits,leading to solder joint cracking and electrical disconnection.Although the formation of KVs has been attributed to the difference in atomic diffusion rates at the Cu/Sn interface,the role of Cu intrinsic"quality"parameters(crystal defects)in this process remains unclear.This work systematically investigated the effects of Cu crystal defects on KVs:Cu substrates with different lattice defects and grain boundaries were prepared using proprietary electrodeposition additives,and the number of defects was quantitatively characterized by micro-strain,geometric dislocation density,and geometric phase analysis.The thermal aging experiments further showed that the formation of intermetallic compounds and KVs was related to crystal defect energy.When the grain boundary energy was higher than the lattice energy,the additional driving force resulted in short-circuit diffusion,causing local Cu depletion and voids.The lowcrystal-defect samples maintained the local Cu/Sn interdiffusion equilibrium,resulting in fewer voids after 1000 h.This study emphasizes that regulating the crystal defects can reduce KVs and provides a new insight for improving the integrated solder joint's reliability.展开更多
The development of single atom catalysts(SACs)with asymmetric active sites by defect regulation provides an encourage potential for oxygen reduction reaction(ORR)and hydrogen evolution reaction(HER),but highly challen...The development of single atom catalysts(SACs)with asymmetric active sites by defect regulation provides an encourage potential for oxygen reduction reaction(ORR)and hydrogen evolution reaction(HER),but highly challenging.Herein,N-doped carbon(N-C)anchored atomically dispersed Ni-N_(3)site with proximity defects(Ni-N_(3)D)induced by Te atoms doping is reported.Benefitting from the inductive effect of proximity defect,the Ni-N_(3)D/Te-N-C catalyst performs excellent ORR and HER performance in alkaline and acid condition.Both in situ characterization and theoretical calculation reveal that the existence of proximity defect effect is conducive to lower rate-determining-step energy barrier of ORR and HER,thus accelerating the multielectron reaction kinetics.This work paves a novel strategy for constructing highactivity bifunctional SACs by defect engineering for development of sustainable energy.展开更多
To enhance boron doping efficiency and reduce metal impurities in diamonds,selecting an appropriate metal solvent is essential for producing p-type diamonds using the high-pressure high-temperature(HPHT)method.This pa...To enhance boron doping efficiency and reduce metal impurities in diamonds,selecting an appropriate metal solvent is essential for producing p-type diamonds using the high-pressure high-temperature(HPHT)method.This paper presents a detailed study of the properties and characteristics of boron-doped diamond(BDD)single crystals grown using FeNi and FeCo solvents through the HPHT method.The results indicate that,with the same TiB_(2)addition ratio,BDD crystals grown using FeCo solvent have a higher concentration of uncompensated boron ions,resulting in improved boron doping efficiency.Additionally,by growing BDD in the same synthesis environment(FeCo-3 wt%TiB_(2))using(111)and(100)seed crystals as growth surfaces,it was found that the boron content in the crystal grown from the(100)seed crystal was higher than that in the crystal grown from the(111)seed crystal.Additionally,the crystals grown with the FeCo solvent contained fewer metal elements(Fe and Co)compared to those produced with the FeNi solvent(Fe and Ni),which supported the growth of high-quality BDD single crystals.This indicated that the choice of growth planes significantly influences the incorporation of boron in diamonds.Our findings hold significant research value for the development of high-quality p-type diamond semiconductors using the HPHT method.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
Electrochemical nitrogen reduction reaction(NRR)is a promising method for the synthesis of ammonia(NH3).However,the electrochemical NRR process remains a great challenge in achieving a high NH3 yield rate and a high F...Electrochemical nitrogen reduction reaction(NRR)is a promising method for the synthesis of ammonia(NH3).However,the electrochemical NRR process remains a great challenge in achieving a high NH3 yield rate and a high Faradaic efficiency(FE)due to the extremely strong N≡N bonds and the competing hydrogen evolution reaction(HER).Recently,bismuth telluride(Bi_(2)Te_(3))with two-dimensional layered structure has been reported as a promising catalyst for N_(2)fixation.Herein,to further enhance its NRR activity,a general doping strategy is developed to introduce and modulate the crystal defects of Bi_(2)Te_(3)nanosheets by adjusting the amount of Ce dopant(denoted as Ce_(x)-Bi_(2)Te_(3),where x represents the designed molar ratio of Ce/Bi).Meanwhile,the crystal defects can be designed and controlled by means of ion substitution and charge compensation.At−0.60 V versus the reversible hydrogen electrode(RHE),Ce_(0.3)-Bi_(2)Te_(3)exhibits a high NH_(3) yield(78.2μg·h^(−1)·mgcat^(−1)),a high FE(19.3%),excellent structural and electrochemical stability.Its outstanding catalytic activity is attributed to the tunable crystal defects by Ce doping.This work not only contributes to enhancing the NRR activity of Bi_(2)Te_(3)nanosheets,but also provides a reliable approach to prepare high-performance electrocatalysts by controlling the type and concentration of crystal defects for artificial N_(2)fixation.展开更多
Two kinds of commercial ammonium polyphosphate （APP） and three kinds of APP which were prepared in the laboratory were studied by X-ray diffraction （XRD）, Fourier transforms infrared spectroscopy （FTIR）, scannin...Two kinds of commercial ammonium polyphosphate （APP） and three kinds of APP which were prepared in the laboratory were studied by X-ray diffraction （XRD）, Fourier transforms infrared spectroscopy （FTIR）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. In identification of the form Ⅱ crystal APP by XRD and FTIR, some discrepancies were discussed. It is pointed out that the absorbance of the FTIR spectra at 682 cm^-1 can exist not only in the form Ⅰ APP, but also in the form Ⅱ APP with the crystal lattice defects. The SEM images indicate that the form Ⅱ APP is of multilayer crystal structure. XRD and TEM can reveal the crystal lattice defects.展开更多
Two types of electroformed nickel liners of shaped charges were prepared by electroforming technique. X-ray diffraction （XRD）, transmission electron microscopy （TEM）, electron backscattering diffraction （EBSD） t...Two types of electroformed nickel liners of shaped charges were prepared by electroforming technique. X-ray diffraction （XRD）, transmission electron microscopy （TEM）, electron backscattering diffraction （EBSD） technique and high resolution electron microscopy （HREM） have been employed to investigate the crystal defects formed in electroformed nickel liners of shaped charges. The result shows that （100） fiber texture which is parallel to the grown direction exists in the electroformed nickel prepared by using direct current electroforming without any additives, and （111） fiber texture exists in the electroformed nickel prepared by using direct current electroforming with additives. The deposits prepared by using direct current electroforming possess columnar grain with an average grain size of 30 μm in width and 170 μm in length. The deposits prepared with additives are composed of a colony structures with grain size of about 29 nm, and a lot of crystal defects such as twins, antiphase boundaries and stacking faults have been observed in the electroformed nickel.展开更多
Zinc oxide（ZnO） is a compound semiconductor with a direct band gap and high exciton binding energy.The unique property,i.e.,high efficient light emission at ultraviolet band,makes ZnO potentially applied to the shor...Zinc oxide（ZnO） is a compound semiconductor with a direct band gap and high exciton binding energy.The unique property,i.e.,high efficient light emission at ultraviolet band,makes ZnO potentially applied to the short-wavelength light emitting devices.However,efficient p-type doping is extremely hard for ZnO.Due to the wide band gap and low valence band energy,the self-compensation from donors and high ionization energy of acceptors are the two main problems hindering the enhancement of free hole concentration.Native defects in ZnO can be divided into donor-like and acceptorlike ones.The self-compensation has been found mainly to originate from zinc interstitial and oxygen vacancy related donors.While the acceptor-like defect,zinc vacancy,is thought to be linked to complex shallow acceptors in group-VA doped ZnO.Therefore,the understanding of the behaviors of the native defects is critical to the realization of high-efficient p-type conduction.Meanwhile,some novel ideas have been extensively proposed,like double-acceptor co-doping,acceptor doping in iso-valent element alloyed ZnO,etc.,and have opened new directions for p-type doping.Some of the approaches have been positively judged.In this article,we thus review the recent（2011-now） research progress of the native defects and p-type doping approaches globally.We hope to provide a comprehensive overview and describe a complete picture of the research status of the p-type doping in ZnO for the reference of the researchers in a similar area.展开更多
Inefficient charge separation and limited light absorption are two critical issues associated with high‐efficiency photocatalytic H2production using TiO2.Surface defects within a certain concentration range in photoc...Inefficient charge separation and limited light absorption are two critical issues associated with high‐efficiency photocatalytic H2production using TiO2.Surface defects within a certain concentration range in photocatalyst materials are beneficial for photocatalytic activity.In this study,surface defects(oxygen vacancies and metal cation replacement defects)were induced with a facile and effective approach by surface doping with low‐cost transition metals(Co,Ni,Cu,and Mn)on ultrafine TiO2.The obtained surface‐defective TiO2exhibited a3–4‐fold improved activity compared to that of the original ultrafine TiO2.In addition,a H2production rate of3.4μmol/h was obtained using visible light(λ>420nm)irradiation.The apparent quantum yield(AQY)at365nm reached36.9%over TiO2‐Cu,significantly more than the commercial P25TiO2.The enhancement of photocatalytic H2production activity can be attributed to improved rapid charge separation efficiency andexpanded light absorption window.This hydrothermal treatment with transition metal was proven to be a very facile and effective method for obtaining surface defects.展开更多
Perovskite BaTaO_(2) N(BTON) is one of the most promising photocatalysts for solar water splitting due to its wide visible-light absorption and suitable conduction/valence bands,but it still confronts the challenge of...Perovskite BaTaO_(2) N(BTON) is one of the most promising photocatalysts for solar water splitting due to its wide visible-light absorption and suitable conduction/valence bands,but it still confronts the challenge of high defect density causing decreased charge separation as well as photocatalytic activity.In this work,we develop a simple zinc doping strategy to greatly suppress its defect density and promote its water reduction performance.It is found that the defect formation on the nitrided Ba(Zn_(1/3-x)Ta_(2/3))O_(3-y)N_z(denoted as BZTON hereafter) will be greatly inhibited when the Zn-doped Ba(Zn_(1/3)Ta_(2/3))O_(3)(BZTO) oxide is used as the nitridation precursor.The structural characterizations and discussion demonstrate that the effective inhibition of Ta^(5+)into Ta^(4+)defects in BZTON mainly results from the easy reduction of zinc ions into metal and further the evaporation of zinc metal under the thermal ammonia flow.Interestingly,this simply doping methodology can be easily extended into the synthesis of SrTaO_(2) N(STON) with extremely low defect density,demonstrating its generality.Benefiting from the successful control to the defect density,the as-obtained BZTON photocatalyst exhibits remarkably promoted charge separation as well as water reduction activity to produce hydrogen with respect to the pristine BTON.Our work may provide an alternative avenue to prepare oxynitride semiconductors with reduced defect density for promoted solar energy conversion.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
Observation under high resolution electron microscope shows that the continuous bombing of high speed ions produces a great amount of vacant site defects.The assembly of vacancies forms vacant dish,and the collapase o...Observation under high resolution electron microscope shows that the continuous bombing of high speed ions produces a great amount of vacant site defects.The assembly of vacancies forms vacant dish,and the collapase of vacant dish forms stacking fault tetrahedrons and oth- er crystal defects.The interfaces between phase ε(Fe_(2-3)N)and phase γ'(Fe_4N)are smooth, straight and coherent,and they have the orientation relationships of(11)//(0001)and [110]/[110] .展开更多
The microstructure of plasma nitrided layer catalyzed by rare-earth elementshas been studied with TEM. The results show that the grains of gamma ft-Fe_4N phase are refined byrare-earth elements and the plane defects i...The microstructure of plasma nitrided layer catalyzed by rare-earth elementshas been studied with TEM. The results show that the grains of gamma ft-Fe_4N phase are refined byrare-earth elements and the plane defects in boundary are increased by rare-earth elements. Theaddition of rare-earth element increases the bombardment effect and the number of crystal defectssuch as vacancies, dislocation loops, twins and stacking faults in gamma ft -Fe_4N phase and canproduce the high-density dislocations in the ferrite of diffusion layer at a distance 0.08mm fromthe surface. The production of a number of crystal defects is one of important reasons whyrare-earth element accelerates the diffusion of nitrogen atoms during plasma-nitriding.展开更多
Doping in pristine 2 D materials brings about the advantage of modulating wide range of mechanical properties simultaneously.However,intrinsic defects(such as Stone-Wales and nanopore) in such hybrid materials are ine...Doping in pristine 2 D materials brings about the advantage of modulating wide range of mechanical properties simultaneously.However,intrinsic defects(such as Stone-Wales and nanopore) in such hybrid materials are inevitable due to complex manu facturing and synthesis processes.Besides that,de fects and irregularities can be intentionally induced in a pristine nanostructure for multi-synchronous modulation of various multi-functional properties.Whatever the case may be,in order to realistically analyse a doped graphene sheet,it is of utmost importance to investigate the compound effect of doping and defects in such 2 D monolayers.Here we present a molecular dynamics based investigation for probing mechanical properties(such as Young’s modulus,post-elastic behaviour,failure strength and strain)of doped graphene(C14 and Si) coupling the effect of inevitable defects.Spatial sensitivity of defect and doping are systematically analyzed considering different rational instances.The study reveals the effects of individual defects and doping along with their possible compounded influences on the failure stress,failure strain,Young’s modulus and constitutive relations beyond the elastic regime.Such detailed mechanical characterization under the practically relevant compound effects would allow us to access the viability of adopting doped graphene in various multifunctional nanoelectromechanical devices and systems in a realistic situation.展开更多
The complicated and diverse deep defects,voids,and grain boundary in the CZTSSe absorber are the main reasons for carrier recombination and efficiency degradation.The further improvement of the open-circuit voltage an...The complicated and diverse deep defects,voids,and grain boundary in the CZTSSe absorber are the main reasons for carrier recombination and efficiency degradation.The further improvement of the open-circuit voltage and fill factor so as to increase the efficiency of CZTSSe device is urgent.In this work,we obtained K-doped CZTSSe absorber by a simple solution method.The medium-sized K atoms,which combine the advantages of light and heavy alkali metals,are able to enter the grain interior as well as segregate at grain boundary.The K-Se liquid phase can improve the absorber crystallinity.We find that the accumulation of the wide bandgap compound K_(2)Sn_(2)S_(5)at grain boundary can increase the contact potential difference of grain boundary,form more effective hole barriers,and enhance the charge separation ability.At the same time,K doping passivates the interface as well as bulk defects and suppresses the non-radiative recombination.The improved crystallinity,enhanced charge transport capability and reduced defect density due to K doping result in a significant enhancement of the carrier lifetime,leading to 13.04%device efficiency.This study provides a new idea for simultaneous realization of grain boundary passivation and defect suppression in inorganic kesterite solar cells.展开更多
Polyanion-based materials are considered one of the most attractive and promising cathode materials for lithiumion batteries(LIBs)due to their good stability,safety,cost-effectiveness,suitable voltages,and minimal env...Polyanion-based materials are considered one of the most attractive and promising cathode materials for lithiumion batteries(LIBs)due to their good stability,safety,cost-effectiveness,suitable voltages,and minimal environmental impact.However,these materials suffer from poor rate capability and low-temperature performance owing to limited electronic and ionic conductivity,which restricts their practical applicability.Recent developments,such as coating material particles with carbon or a conductive polymer,crystal deformation through the doping of foreign metal ions,and the production of nanostructured materials,have significantly enhanced the electrochemical performances of these materials.The successful applications of polyanion-based materials,especially in lithium-ion batteries,have been extensively reported.This comprehensive review discusses the current progress in crystal deformation in polyanion-based cathode materials,including phosphates,fluorophosphates,pyrophosphates,borates,silicates,sulfates,fluorosilicates,and oxalates.Therefore,this review provides detailed discussions on their synthesis strategies,electrochemical performance,and the doping of various ions.展开更多
Photocatalytic synthesis of hydrogen peroxide has gradually become a promising method for in-situ pro-duction of hydrogen peroxide,which relies on sustainable solar energy.However,the commonly used photocatalyst,i.e.,...Photocatalytic synthesis of hydrogen peroxide has gradually become a promising method for in-situ pro-duction of hydrogen peroxide,which relies on sustainable solar energy.However,the commonly used photocatalyst,i.e.,carbon nitride(CN),still suffers from the drawbacks of narrow light absorption range and fast charge recombination.Here,we report a facile method to introduce nitrogen defects into carbon nitride together with sodium ion.By adjusting the ratio of sodium dicyandiamide,the band gap of carbon nitride can be controlled,while the carrier separation and transfer ability of carbon nitride is improved.The modified CN with sodium doping and nitrogen defect(SD-CN)demonstrates outstanding H_(2)O_(2)pro-duction performance(H_(2)O_(2)yield rate of 297.2μmol L^(−1)h^(−1))under visible light irradiation,which is approximately 9.8 times higher than that of pristine CN.This work deepens the understanding of the coordinated effect of structural defect and element doping of carbon nitride on the photocatalytic H_(2)O_(2)production performance,and provides new insight into the design of photocatalytic system for efficient production of H_(2)O_(2).展开更多
Single crystallization has proven to be effective in enhancing the capacity and stability of Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(SNCM)cathode materials,particularly at high cut-off voltages.Nevertheless,the synthesi...Single crystallization has proven to be effective in enhancing the capacity and stability of Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(SNCM)cathode materials,particularly at high cut-off voltages.Nevertheless,the synthesis of high-quality single-crystal particles remains challenging because of severe particle agglomeration and irregular morphologies.Moreover,the limited kinetics of solid-phase Li^(+)diffusion pose a significant concern because of the extended diffusion path in large single-crystal particles.To address these challenges,we developed a Tb-doped single-crystal LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)(SNCM-Tb)cathode material using a straightforward mixed molten salt sintering process.The Tb-doped Ni-rich single crystals presented a quasi-spherical morphology,which is markedly different from those reported in previous studies.Tb^(4+)oping significantly enhanced the dynamic transport of Li^(+)ions in the layered oxide phase by reducing the Ni valence state and creating Li vacancies.A SNCM-Tb material with 1 at%Tb doping shows a Li^(+)diffusion coefficient up to more than 9 times higher than pristine SNCM in the non-diluted state.In situ X-ray diffraction analysis demonstrated a significantly facilitated H1-H2-H3 phase transition in the SNCM-Tb materials,thereby enhancing their rate capacity and structural stability.SNCM-Tb exhibited a reversible capacity of 186.9 mA h g^(-1)at 5 C,retaining 94.6%capacity after 100 cycles at 0.5 C under a 4,5 V cut-off.Our study elucidates the Tb^(4+)doping mechanisms and proposes a scalable method for enhancing the performance of single-crystal Ni-rich NCM materials.展开更多
基金National Natural Science Foundation of China (62104061, 62074052, 61974173 and 52072327)。
文摘Solution-processed Cu(In,Ga)Se_(2)(CIGS) solar cells suffer from serious carrier recombination and power conversion efficiency(PCE) loss because of the poor film properties and easy formation of defects.Herein, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved opencircuit voltage(VOC) of 662 m V and fill factor(FF) of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.
文摘The development of metal-free carbon catalysts has garnered significant attention as a promising approach to address the challenges of sustainable catalysis,particularly in the replacement of toxic and environmentally hazardous mercury-based systems for the coal-based PVC industry.Within a decade of development,the catalytic performance of carbon catalysts has been improved greatly and even shows superiorities over metal catalysts in some cases,which have demonstrated great potential as sustainable alternatives to mercury catalysts.This review provides a comprehensive summary of the recent advancements in carbon catalysts for acetylene hydrochlorination.It encompasses a wide range of aspects,including the identification of active sites from heteroatom doping to intrinsic carbon defects,the various synthetic strategies employed,the reaction and deactivation mechanisms of carbon catalysts,and the current insights into the key challenges that are encountered on the journey from laboratory research to scalable commercialization within the field of carbon catalysts.The review offers foundational insights and practical guidelines for designing green carbon catalysts systems,not only for acetylene hydrochlorination but also for other heterogeneous catalytic reactions.
基金financially supported by the National Natural Science Foundation of China(Nos.62274172 and 62304143)High-level Talent Innovation and Entrepreneurship Plan of Shenzhen Key Technology Research and Development Team Funding Application(No.JSGGKQTD20221101115650008)+2 种基金Shenzhen-Hong Kong-Macao Science and Technology Plan Project(Category C)(No.SGDX20220530111004028)Macao Science and Technology Development Fund(FDCT)for funding(No.0013/2024/RIB1)the Multi-Year Research Grant(MYRG)from University of Macao(Nos.MYRG-GRG2023-00140-IAPME-UMDF and MYRG-GRG2024-00206-IAPME)
文摘Kirkendall voids(KVs)at the Cu/Sn interface are a typical failure in integrated circuits,leading to solder joint cracking and electrical disconnection.Although the formation of KVs has been attributed to the difference in atomic diffusion rates at the Cu/Sn interface,the role of Cu intrinsic"quality"parameters(crystal defects)in this process remains unclear.This work systematically investigated the effects of Cu crystal defects on KVs:Cu substrates with different lattice defects and grain boundaries were prepared using proprietary electrodeposition additives,and the number of defects was quantitatively characterized by micro-strain,geometric dislocation density,and geometric phase analysis.The thermal aging experiments further showed that the formation of intermetallic compounds and KVs was related to crystal defect energy.When the grain boundary energy was higher than the lattice energy,the additional driving force resulted in short-circuit diffusion,causing local Cu depletion and voids.The lowcrystal-defect samples maintained the local Cu/Sn interdiffusion equilibrium,resulting in fewer voids after 1000 h.This study emphasizes that regulating the crystal defects can reduce KVs and provides a new insight for improving the integrated solder joint's reliability.
基金financially supported by the National Natural Science Foundation of China(22478432,22108306,22178388)Taishan Scholars Program of Shandong Province(tsqn201909065)+2 种基金Shandong Provincial Natural Science Foundation(ZR2024JQ004)Innovation Fund Project for Graduate Student of China University of Petroleum(East China)the Fundamental Research Funds for the Central Universities(No.25CX04020A)。
文摘The development of single atom catalysts(SACs)with asymmetric active sites by defect regulation provides an encourage potential for oxygen reduction reaction(ORR)and hydrogen evolution reaction(HER),but highly challenging.Herein,N-doped carbon(N-C)anchored atomically dispersed Ni-N_(3)site with proximity defects(Ni-N_(3)D)induced by Te atoms doping is reported.Benefitting from the inductive effect of proximity defect,the Ni-N_(3)D/Te-N-C catalyst performs excellent ORR and HER performance in alkaline and acid condition.Both in situ characterization and theoretical calculation reveal that the existence of proximity defect effect is conducive to lower rate-determining-step energy barrier of ORR and HER,thus accelerating the multielectron reaction kinetics.This work paves a novel strategy for constructing highactivity bifunctional SACs by defect engineering for development of sustainable energy.
基金supported by the National Natural Science Foundation of China(Grant Nos.12274373 and 12274372)the Natural Science Foundation of Henan Province(Grant Nos.242300421155 and 252300421475)+2 种基金the Key Research Projects of Higher Education Institutions in Henan Province(Grant No.25A140008)the Natural Science Foundation of Chongqing,China(Grant Nos.CSTB2023NSCQ-LZX0100 and CSTB2023NSCQ-MSX0362)Central Plains Science and Technology Innovation Youth Top Notch Talents,and Independent Innovation Project for Graduate Students of Zhengzhou University(Grant No.20250450).
文摘To enhance boron doping efficiency and reduce metal impurities in diamonds,selecting an appropriate metal solvent is essential for producing p-type diamonds using the high-pressure high-temperature(HPHT)method.This paper presents a detailed study of the properties and characteristics of boron-doped diamond(BDD)single crystals grown using FeNi and FeCo solvents through the HPHT method.The results indicate that,with the same TiB_(2)addition ratio,BDD crystals grown using FeCo solvent have a higher concentration of uncompensated boron ions,resulting in improved boron doping efficiency.Additionally,by growing BDD in the same synthesis environment(FeCo-3 wt%TiB_(2))using(111)and(100)seed crystals as growth surfaces,it was found that the boron content in the crystal grown from the(100)seed crystal was higher than that in the crystal grown from the(111)seed crystal.Additionally,the crystals grown with the FeCo solvent contained fewer metal elements(Fe and Co)compared to those produced with the FeNi solvent(Fe and Ni),which supported the growth of high-quality BDD single crystals.This indicated that the choice of growth planes significantly influences the incorporation of boron in diamonds.Our findings hold significant research value for the development of high-quality p-type diamond semiconductors using the HPHT method.
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(Nos.22074137 and 21721003).
文摘Electrochemical nitrogen reduction reaction(NRR)is a promising method for the synthesis of ammonia(NH3).However,the electrochemical NRR process remains a great challenge in achieving a high NH3 yield rate and a high Faradaic efficiency(FE)due to the extremely strong N≡N bonds and the competing hydrogen evolution reaction(HER).Recently,bismuth telluride(Bi_(2)Te_(3))with two-dimensional layered structure has been reported as a promising catalyst for N_(2)fixation.Herein,to further enhance its NRR activity,a general doping strategy is developed to introduce and modulate the crystal defects of Bi_(2)Te_(3)nanosheets by adjusting the amount of Ce dopant(denoted as Ce_(x)-Bi_(2)Te_(3),where x represents the designed molar ratio of Ce/Bi).Meanwhile,the crystal defects can be designed and controlled by means of ion substitution and charge compensation.At−0.60 V versus the reversible hydrogen electrode(RHE),Ce_(0.3)-Bi_(2)Te_(3)exhibits a high NH_(3) yield(78.2μg·h^(−1)·mgcat^(−1)),a high FE(19.3%),excellent structural and electrochemical stability.Its outstanding catalytic activity is attributed to the tunable crystal defects by Ce doping.This work not only contributes to enhancing the NRR activity of Bi_(2)Te_(3)nanosheets,but also provides a reliable approach to prepare high-performance electrocatalysts by controlling the type and concentration of crystal defects for artificial N_(2)fixation.
基金Sponsored by the National Key Technology R&D Program(2006BAE03B05-2)
文摘Two kinds of commercial ammonium polyphosphate （APP） and three kinds of APP which were prepared in the laboratory were studied by X-ray diffraction （XRD）, Fourier transforms infrared spectroscopy （FTIR）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. In identification of the form Ⅱ crystal APP by XRD and FTIR, some discrepancies were discussed. It is pointed out that the absorbance of the FTIR spectra at 682 cm^-1 can exist not only in the form Ⅰ APP, but also in the form Ⅱ APP with the crystal lattice defects. The SEM images indicate that the form Ⅱ APP is of multilayer crystal structure. XRD and TEM can reveal the crystal lattice defects.
基金supported in part by National Natural Science Foundation of Chinaunder Grant No.50671012
文摘Two types of electroformed nickel liners of shaped charges were prepared by electroforming technique. X-ray diffraction （XRD）, transmission electron microscopy （TEM）, electron backscattering diffraction （EBSD） technique and high resolution electron microscopy （HREM） have been employed to investigate the crystal defects formed in electroformed nickel liners of shaped charges. The result shows that （100） fiber texture which is parallel to the grown direction exists in the electroformed nickel prepared by using direct current electroforming without any additives, and （111） fiber texture exists in the electroformed nickel prepared by using direct current electroforming with additives. The deposits prepared by using direct current electroforming possess columnar grain with an average grain size of 30 μm in width and 170 μm in length. The deposits prepared with additives are composed of a colony structures with grain size of about 29 nm, and a lot of crystal defects such as twins, antiphase boundaries and stacking faults have been observed in the electroformed nickel.
基金Project supported by the State Key Program for Basic Research of China(Grant No.2011CB302003)the National Natural Science Foundation of China(Grant Nos.61274058,61322403,61504057,and 61574075)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20130013 and BK20150585)the Six Talent Peaks Project in Jiangsu Province,China(Grant No.2014XXRJ001)
文摘Zinc oxide（ZnO） is a compound semiconductor with a direct band gap and high exciton binding energy.The unique property,i.e.,high efficient light emission at ultraviolet band,makes ZnO potentially applied to the short-wavelength light emitting devices.However,efficient p-type doping is extremely hard for ZnO.Due to the wide band gap and low valence band energy,the self-compensation from donors and high ionization energy of acceptors are the two main problems hindering the enhancement of free hole concentration.Native defects in ZnO can be divided into donor-like and acceptorlike ones.The self-compensation has been found mainly to originate from zinc interstitial and oxygen vacancy related donors.While the acceptor-like defect,zinc vacancy,is thought to be linked to complex shallow acceptors in group-VA doped ZnO.Therefore,the understanding of the behaviors of the native defects is critical to the realization of high-efficient p-type conduction.Meanwhile,some novel ideas have been extensively proposed,like double-acceptor co-doping,acceptor doping in iso-valent element alloyed ZnO,etc.,and have opened new directions for p-type doping.Some of the approaches have been positively judged.In this article,we thus review the recent（2011-now） research progress of the native defects and p-type doping approaches globally.We hope to provide a comprehensive overview and describe a complete picture of the research status of the p-type doping in ZnO for the reference of the researchers in a similar area.
基金supported by the Double First‐rate Subject‐Food Science and Engineering Program of Hebei Province (2018SPGCA18)Young Tip‐top Talents Plan of Universities and Colleges in Hebei Province of China (BJ2017026)the Specific Foundation for Doctor in Hebei Agriculture University of China (ZD201709)~~
文摘Inefficient charge separation and limited light absorption are two critical issues associated with high‐efficiency photocatalytic H2production using TiO2.Surface defects within a certain concentration range in photocatalyst materials are beneficial for photocatalytic activity.In this study,surface defects(oxygen vacancies and metal cation replacement defects)were induced with a facile and effective approach by surface doping with low‐cost transition metals(Co,Ni,Cu,and Mn)on ultrafine TiO2.The obtained surface‐defective TiO2exhibited a3–4‐fold improved activity compared to that of the original ultrafine TiO2.In addition,a H2production rate of3.4μmol/h was obtained using visible light(λ>420nm)irradiation.The apparent quantum yield(AQY)at365nm reached36.9%over TiO2‐Cu,significantly more than the commercial P25TiO2.The enhancement of photocatalytic H2production activity can be attributed to improved rapid charge separation efficiency andexpanded light absorption window.This hydrothermal treatment with transition metal was proven to be a very facile and effective method for obtaining surface defects.
基金supported by the National Natural Science Foundation of China (21633009, 21925206)the National Key R&D Program of China (2020YFA0406102)+2 种基金the Dalian National Laboratory for Clean Energy (DNL) Cooperation Fund,Chinese Academy of Sciences (DNL 201913)the International Partnership Program of Chinese Academy of Sciences (121421KYSB20190025)the DICP foundation of innovative research (DICP I201927)。
文摘Perovskite BaTaO_(2) N(BTON) is one of the most promising photocatalysts for solar water splitting due to its wide visible-light absorption and suitable conduction/valence bands,but it still confronts the challenge of high defect density causing decreased charge separation as well as photocatalytic activity.In this work,we develop a simple zinc doping strategy to greatly suppress its defect density and promote its water reduction performance.It is found that the defect formation on the nitrided Ba(Zn_(1/3-x)Ta_(2/3))O_(3-y)N_z(denoted as BZTON hereafter) will be greatly inhibited when the Zn-doped Ba(Zn_(1/3)Ta_(2/3))O_(3)(BZTO) oxide is used as the nitridation precursor.The structural characterizations and discussion demonstrate that the effective inhibition of Ta^(5+)into Ta^(4+)defects in BZTON mainly results from the easy reduction of zinc ions into metal and further the evaporation of zinc metal under the thermal ammonia flow.Interestingly,this simply doping methodology can be easily extended into the synthesis of SrTaO_(2) N(STON) with extremely low defect density,demonstrating its generality.Benefiting from the successful control to the defect density,the as-obtained BZTON photocatalyst exhibits remarkably promoted charge separation as well as water reduction activity to produce hydrogen with respect to the pristine BTON.Our work may provide an alternative avenue to prepare oxynitride semiconductors with reduced defect density for promoted solar energy conversion.
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.
文摘Observation under high resolution electron microscope shows that the continuous bombing of high speed ions produces a great amount of vacant site defects.The assembly of vacancies forms vacant dish,and the collapase of vacant dish forms stacking fault tetrahedrons and oth- er crystal defects.The interfaces between phase ε(Fe_(2-3)N)and phase γ'(Fe_4N)are smooth, straight and coherent,and they have the orientation relationships of(11)//(0001)and [110]/[110] .
文摘The microstructure of plasma nitrided layer catalyzed by rare-earth elementshas been studied with TEM. The results show that the grains of gamma ft-Fe_4N phase are refined byrare-earth elements and the plane defects in boundary are increased by rare-earth elements. Theaddition of rare-earth element increases the bombardment effect and the number of crystal defectssuch as vacancies, dislocation loops, twins and stacking faults in gamma ft -Fe_4N phase and canproduce the high-density dislocations in the ferrite of diffusion layer at a distance 0.08mm fromthe surface. The production of a number of crystal defects is one of important reasons whyrare-earth element accelerates the diffusion of nitrogen atoms during plasma-nitriding.
基金the financial support received from Ministry of Human Resource and Development (MHRD), Govt. of India during the period of this research workenhanced financial support from IIT Kanpur during this research。
文摘Doping in pristine 2 D materials brings about the advantage of modulating wide range of mechanical properties simultaneously.However,intrinsic defects(such as Stone-Wales and nanopore) in such hybrid materials are inevitable due to complex manu facturing and synthesis processes.Besides that,de fects and irregularities can be intentionally induced in a pristine nanostructure for multi-synchronous modulation of various multi-functional properties.Whatever the case may be,in order to realistically analyse a doped graphene sheet,it is of utmost importance to investigate the compound effect of doping and defects in such 2 D monolayers.Here we present a molecular dynamics based investigation for probing mechanical properties(such as Young’s modulus,post-elastic behaviour,failure strength and strain)of doped graphene(C14 and Si) coupling the effect of inevitable defects.Spatial sensitivity of defect and doping are systematically analyzed considering different rational instances.The study reveals the effects of individual defects and doping along with their possible compounded influences on the failure stress,failure strain,Young’s modulus and constitutive relations beyond the elastic regime.Such detailed mechanical characterization under the practically relevant compound effects would allow us to access the viability of adopting doped graphene in various multifunctional nanoelectromechanical devices and systems in a realistic situation.
基金supported by the National Natural Science Foundation of China(No.62074102)Science and Technology Plan Project of Shenzhen(No.20220808165025003)China+1 种基金Science and Technology Project of Guizhou Province(No.QKHJCZK[2023]YB130)The Growth Plan for Young Science and Technology Talents of Guizhou Education Department(No.QJH KY[2017]223)。
文摘The complicated and diverse deep defects,voids,and grain boundary in the CZTSSe absorber are the main reasons for carrier recombination and efficiency degradation.The further improvement of the open-circuit voltage and fill factor so as to increase the efficiency of CZTSSe device is urgent.In this work,we obtained K-doped CZTSSe absorber by a simple solution method.The medium-sized K atoms,which combine the advantages of light and heavy alkali metals,are able to enter the grain interior as well as segregate at grain boundary.The K-Se liquid phase can improve the absorber crystallinity.We find that the accumulation of the wide bandgap compound K_(2)Sn_(2)S_(5)at grain boundary can increase the contact potential difference of grain boundary,form more effective hole barriers,and enhance the charge separation ability.At the same time,K doping passivates the interface as well as bulk defects and suppresses the non-radiative recombination.The improved crystallinity,enhanced charge transport capability and reduced defect density due to K doping result in a significant enhancement of the carrier lifetime,leading to 13.04%device efficiency.This study provides a new idea for simultaneous realization of grain boundary passivation and defect suppression in inorganic kesterite solar cells.
文摘Polyanion-based materials are considered one of the most attractive and promising cathode materials for lithiumion batteries(LIBs)due to their good stability,safety,cost-effectiveness,suitable voltages,and minimal environmental impact.However,these materials suffer from poor rate capability and low-temperature performance owing to limited electronic and ionic conductivity,which restricts their practical applicability.Recent developments,such as coating material particles with carbon or a conductive polymer,crystal deformation through the doping of foreign metal ions,and the production of nanostructured materials,have significantly enhanced the electrochemical performances of these materials.The successful applications of polyanion-based materials,especially in lithium-ion batteries,have been extensively reported.This comprehensive review discusses the current progress in crystal deformation in polyanion-based cathode materials,including phosphates,fluorophosphates,pyrophosphates,borates,silicates,sulfates,fluorosilicates,and oxalates.Therefore,this review provides detailed discussions on their synthesis strategies,electrochemical performance,and the doping of various ions.
基金supported by the National Natural Science Foundation of China(No.22376159)the Fundamental Research Funds for the Central Universities(No.2022-4-ZD-08).
文摘Photocatalytic synthesis of hydrogen peroxide has gradually become a promising method for in-situ pro-duction of hydrogen peroxide,which relies on sustainable solar energy.However,the commonly used photocatalyst,i.e.,carbon nitride(CN),still suffers from the drawbacks of narrow light absorption range and fast charge recombination.Here,we report a facile method to introduce nitrogen defects into carbon nitride together with sodium ion.By adjusting the ratio of sodium dicyandiamide,the band gap of carbon nitride can be controlled,while the carrier separation and transfer ability of carbon nitride is improved.The modified CN with sodium doping and nitrogen defect(SD-CN)demonstrates outstanding H_(2)O_(2)pro-duction performance(H_(2)O_(2)yield rate of 297.2μmol L^(−1)h^(−1))under visible light irradiation,which is approximately 9.8 times higher than that of pristine CN.This work deepens the understanding of the coordinated effect of structural defect and element doping of carbon nitride on the photocatalytic H_(2)O_(2)production performance,and provides new insight into the design of photocatalytic system for efficient production of H_(2)O_(2).
基金financial support from the horizontal project“Research and Application of All-Solid-State Lithium-Ion Battery Technology” (MH20220255)from Zibo Torch Energy Co.,Ltdthe Heilongjiang Touyan Innovation Team Program (HITTY20190033)+1 种基金Zibo Torch Energy Co.,Ltd.China State Shipbuilding Corporation,Limited for their financial support。
文摘Single crystallization has proven to be effective in enhancing the capacity and stability of Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(SNCM)cathode materials,particularly at high cut-off voltages.Nevertheless,the synthesis of high-quality single-crystal particles remains challenging because of severe particle agglomeration and irregular morphologies.Moreover,the limited kinetics of solid-phase Li^(+)diffusion pose a significant concern because of the extended diffusion path in large single-crystal particles.To address these challenges,we developed a Tb-doped single-crystal LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)(SNCM-Tb)cathode material using a straightforward mixed molten salt sintering process.The Tb-doped Ni-rich single crystals presented a quasi-spherical morphology,which is markedly different from those reported in previous studies.Tb^(4+)oping significantly enhanced the dynamic transport of Li^(+)ions in the layered oxide phase by reducing the Ni valence state and creating Li vacancies.A SNCM-Tb material with 1 at%Tb doping shows a Li^(+)diffusion coefficient up to more than 9 times higher than pristine SNCM in the non-diluted state.In situ X-ray diffraction analysis demonstrated a significantly facilitated H1-H2-H3 phase transition in the SNCM-Tb materials,thereby enhancing their rate capacity and structural stability.SNCM-Tb exhibited a reversible capacity of 186.9 mA h g^(-1)at 5 C,retaining 94.6%capacity after 100 cycles at 0.5 C under a 4,5 V cut-off.Our study elucidates the Tb^(4+)doping mechanisms and proposes a scalable method for enhancing the performance of single-crystal Ni-rich NCM materials.
