Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electroc...Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electrocatalysts with high SSA and optimized structure is of great significance but remains a tremendous challenge.Herein,we propose a general strategy for fabrication of mesoporous perovskite oxide nanosheets(MPONs)with controllable atomic doping via self-sacrificial template-induced nanostructure modulation.A variety of MPONs including LaFeO_(3),A-site-doped LaFeO_(3)(A-LaFeO_(3),where A is Pr,Nd,Sm,Eu,or Gd)and B-site-doped LaFeO_(3)(B-LaFeO_(3),where B is Mn,Co,Ni,Cu,or Zn)have been achieved.Interestingly,it is discovered that the catalytic activities of A-LaFeO_(3) MPONs as OER catalysts are overall higher than those of B-LaFeO_(3) ones.Especially,the screened Eu-LaFeO_(3) MPONs only require a low overpotential of 267 mV at 10 mA cm^(−2),outperforming most reported perovskite oxides.The superior catalytic activity of Eu-LaFeO_(3) MPONs is attributed to their favorable porous structure,which increases the density of active sites,and enhanced lattice oxygen participation,which improves the intrinsic activity.This study provides guidance for the design and controlled synthesis of advanced rare-earth-doped MPONs with ultrahigh SSA for enhanced electrocatalysis.展开更多
Additive engineering significantly enhances the photovoltaic performance of perovskite solar cells(PSCs).The atomistic and mechanistic origins of these jfurther investigation to fully understand the physicochemical in...Additive engineering significantly enhances the photovoltaic performance of perovskite solar cells(PSCs).The atomistic and mechanistic origins of these jfurther investigation to fully understand the physicochemical interactions of additives with the perovskite lattice,band structure,and charge carriers.Herein,how additives of cellulose triacetate(CTA)improve the photovoltaic performance and stability of perovskite solar cells(PSCs)is shown.These improvements are found to stem from the formation of hydrogen bonds between CTA molecules and organic cations.The Kelvin probe force microscopy results show that contact potential difference variation under dark and light conditions increases from 79.68 to 141.24 mV by doping CTA,indicating enhanced separation of electron-hole pairs in perovskite.The piezoresponse force microscopy(PFM)tests indicate that CTA additives reduce the PFM amplitude by approximately 50 pm under dark and light conditions and inhibit flipping from antiferroelectric domains to ferroelectric domains.Moreover,the CTA additives regulate the charge distribution within the PbI6 octahedron and bind organic ions through hydrogen bonding,forming a compact film structure.These findings not only improve the long-term stability of organic-inorganic hybrid perovskites(OIHPs),but also pave the way for developing novel strategies for large-scale PSCs.展开更多
Photocatalysis has attracted much attention in recent years due to its potential in solving energy and environmental issues. Even though numerous achievements have been made, the photocatalytic systems developed to da...Photocatalysis has attracted much attention in recent years due to its potential in solving energy and environmental issues. Even though numerous achievements have been made, the photocatalytic systems developed to date are still far from practical applications due to the low efficiency and poor durability. Efficient light absorption and charge separation are two of the key factors for the exploration of high performance photocatalytic systems, which is generally difficult to be obtained in a single photocata- lyst. The combination of various materials to form heterojunctions provides an effective way to better harvest solar energy and to facilitate charge separation and transfer, thus enhancing the photocatalytic activity and stability. This review concisely summarizes the recent development of visible light respon- sive heterojunctions, including the preparation and performances of semiconductor/semiconductor junctions, semiconductor/cocatalyst junctions, semiconductor/metal junctions, semiconductor/non- metal junctions, and surface heterojunctions, and their mechanism for enhanced light harvesting and charge separation/transfer.展开更多
As a kind of valuable chemicals,hydrogen peroxide(H2O2)has aroused growing attention in many fields.However,H2O2 production via traditional anthraquinone process suffers from challenges of large energy consumption and...As a kind of valuable chemicals,hydrogen peroxide(H2O2)has aroused growing attention in many fields.However,H2O2 production via traditional anthraquinone process suffers from challenges of large energy consumption and heavy carbon footprint.Alternatively,photoelectrocatalytic(PEC)production of H2O2 has shown great promises to make H2O2 a renewable fuel to store solar energy.Transition‐metal‐oxide(TMO)semiconductor based photoelectrocatalysts are among the most promising candidates for PEC H2O2 production.In this work,the fundamentals of H2O2 synthesis through PEC process are briefly introduced,followed by the state‐of‐the‐art of TMO semiconductor based photoelectrocatalysts for PEC production H2O2.Then,the progress on H2O2 fuel cells from on‐site PEC production is presented.Furthermore,the challenges and future perspectives of PEC H2O2 production are discussed.This review aims to provide inspiration for the PEC production of H2O2 as a renewable solar fuel.展开更多
Photoelectrochemical(PEC)water splitting process is regarded as a promising route to generate hydrogen by solar energy and at the heart of PEC is efficient electrode design.Great progress has been achieved in the aspe...Photoelectrochemical(PEC)water splitting process is regarded as a promising route to generate hydrogen by solar energy and at the heart of PEC is efficient electrode design.Great progress has been achieved in the aspects of material design,cocatalyst study,and electrode fabrication over the past decades.However,some key challenges remain unsolved,including the most demanded conversion efficiency issue.As three critical steps,i.e.light harvesting,charge transfer and surface reaction of the PEC process,occur in a huge range of time scale(from10-12s to100s),how to manage these subsequent steps to facilitate the seamless cooperation between each step to realize efficient PEC process is essentially important.This review focuses on an integral consideration of the three key criteria based on the recent progress on high efficient and stable photoelectrode design in PEC.The basic principles and potential strategies are summarized.Moreover,the challenge and perspective are also discussed.展开更多
The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulati...The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulating their catalytic sites are a significant challenge in this field. Here,we propose an electrochemical surface restructuring strategy to design synergistically interactive phosphorus-doped carbon@MoP electrocatalysts for the HER. A simple electrochemical cycling method is developed to tune the thickness of the carbon layers that cover on MoP core,which significantly influences HER performance. Experimental investigations and theoretical calculations indicate that the inactive surface carbon layers can be removed through electrochemical cycling,leading to a close bond between the MoP and a few layers of coated graphene. The electronsdonated by the MoP core enhance the adhesion and electronegativity of the carbon layers;the negatively charged carbon layers act as an active surface. The electrochemically induced optimization of the surface/interface electronic structures in the electrocatalysts significantly promotes the HER. Using this strategy endows the catalyst with excellent activity in terms of the HER in both acidic and alkaline environments(current density of 10 mA cm^(-2) at low overpotentials,of 68 mV in 0.5 M H_(2)SO_(4) and 67 mV in 1.0 M KOH).展开更多
Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this...Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this work,two-dimensional(2D)ultrathin FePS3 nanosheets,a typical ternary metal phosphosulfide,are first prepared by ultrasonic exfoliation.The novel 2D/2D heterojunction of FePS3 nanosheets@MXene composite is then successfully synthesized by in situ mixing ultrathin MXene nanosheets with FePS3 nanosheets.The resultant FePS3 nanosheets@MXene hybrids can increase the electronic conductivity and specific surface area,assuring excellent surface and interfacial charge transfer abilities.Furthermore,the unique heterojunction endows FePS3 nanosheets@MXene composite to promote the diffusion of Na^+ and alleviate the drastic change in volume in the cyclic process,enhancing the sodium storage capability.Consequently,the few-layered FePS3 nanosheets uniformly coated by ultrathin MXene provide an exceptional reversible capacity of 676.1 mAh g^−1 at the current of 100 mA g^−1 after 90 cycles,which is equivalent to around 90.6% of the second-cycle capacity(746.4 mAh g^−1).This work provides an original protocol for constructing 2D/2D material and demonstrates the FePS3@MXene composite as a potential anode material with excellent property for sodium-ion batteries.展开更多
Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5...Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5×10^-30S cm^-1),associated lithium polysulfides(PSs),and their migration from the cathode to the anode.In this study,a separator coated with a Ketjen black(KB)/Nafion composite was used in an LSB with a sulfur loading up to 7.88 mg cm^-2to mitigate the PS migration.A minimum specific capacity(Cs)loss of 0.06%was obtained at 0.2 C-rate at a high sulfur loading of 4.39 mg cm^-2.Furthermore,an initial areal capacity up to 6.70 mAh cm^-2 was obtained at a sulfur loading of 7.88 mg cm^-2.The low Cs loss and high areal capacity associated with the high sulfur loading are attributed to the large surface area of the KB and sulfonate group(SO3^-)of Nafion,respectively,which could physically and chemically trap the PSs.展开更多
Li-rich materials,due to their high capacity(>250 mAh·g^(-1)),have recently been considered as an alternative to the current generation of cathode materials for Li-ion batteries(LIBs).However,their inferior cy...Li-rich materials,due to their high capacity(>250 mAh·g^(-1)),have recently been considered as an alternative to the current generation of cathode materials for Li-ion batteries(LIBs).However,their inferior cycling stability limits their practical applicability.Doping is a common technique to solve this problem.However,anion doping remains relatively underexplored.Fluorine(F)is one of the most effective anion dopants owning to the improved capacity,cycling stability,and rate performance in batteries.The explanations and experimental results,however,vary significantly from study to study.Herein,we find that bulk F-doping significantly improves both rate performance and cycling stability,likely driven by charge compensation and greater electronegativity.Additionally,bulk F-doping occasionally improves capacity via enhanced activation and occasionally decreases capacity by preventing activation from occurring.Surface F-doping has similar effects to bulk F-doping on capacity and stability,while significantly hindering the rate performance.Furthermore,the improvements in surface-doped materials do not appear to be a result of specific surface modification,and instead can be ascribed to the effect of fluorine on the near-surface bulk material.Greater understanding of fluo-rine's influence on activation,in particular,is required to unlock the full potential of synergistic cation/anion co-doping.展开更多
The lithium sulfur batteries(LSBs) are considered as one of the promising next generation energy storage devices due to the high theoretical specific capacity of sulfur(1675 m Ah g-1), naturally available, low cost.Ho...The lithium sulfur batteries(LSBs) are considered as one of the promising next generation energy storage devices due to the high theoretical specific capacity of sulfur(1675 m Ah g-1), naturally available, low cost.However, the practical LSBs are impeded by the well-known "shuttle effect" combined with other technical drawbacks. The "shuttle effect" causes rapid capacity decay, severe self-discharging and low active material utilization. The polysulfide(PS) which has lone pair electrons in each sulfur atom is considered as Lewis base and shows strong affinity to various polar, Lewis acid and catenation interactive materials but very weakly interacts with the non-polar conductive carbons. The "shuttle effect" occurs due to the diffusion of high order PS from the cathode to the anode and then low-order PS back to the cathode. The PS is polar and, due to a lone pair of electrons associated with the sulfur atom, is considered a Lewis base. As such, the PS shows a strong affinity with various polar and Lewis acid materials. In addition, a more novel trapping can be performance through a catenation reaction. For LSBs to compete with the state-of-the-art lithium ion batteries(LIBs), the LSB areal capacity need to be ~6 m Ah cm-2(which is proportional to sulfur loading). To achieve this target the PS shuttling needs to mitigate, which can be achieved through using functional materials. This review addresses the aforementioned phenomena by considering the PS phase interacts with the various functional materials and how this impacts areal capacity and cycling stability of LSBs.展开更多
Here we report a new one-step thermal polycondensation process to form crinkly graphitic carbon nitride nanosheets(CGCNNs)via supramolecular preorganization,using a mixture of urea and melamine as the starting materia...Here we report a new one-step thermal polycondensation process to form crinkly graphitic carbon nitride nanosheets(CGCNNs)via supramolecular preorganization,using a mixture of urea and melamine as the starting material.Systematical studies reveal that the newly developed CGCNNs significantly strengthen the optical absorption,widen the bandgap,and increase the Hall mobility and carrier density compared to that of its bulk counterpart,regardless of the similar chemical composition and structure.As a result,the photocatalytic hydrogen production rate is improved by 7 times.Moreover,Na doping of CGCNNs can further promote its photocatalytic activity,leading to an excellent photocatalytic hydrogen production rate of 250.9μmol h^(–1),which is approximately 10.5 times higher than its bulk counterpart.Moreover,an impressive apparent quantum efficiency of 19.12%is achieved at 420 nm.This study provides a facile strategy for the design of efficient low-cost carbon-nitride-based photocatalysts for solar fuel production.展开更多
Photoelectrochemical water splitting is a sustainable path to generate valuable hydrogen using sunlight and water as the only inputs.Despite significant efforts to date,it is still a challenge to achieve photoelectrod...Photoelectrochemical water splitting is a sustainable path to generate valuable hydrogen using sunlight and water as the only inputs.Despite significant efforts to date,it is still a challenge to achieve photoelectrode with superior performance and long-term stability.Many bismuth-based semiconductor materials have demonstrated excellent visible light harvesting capability and suitable band edge for water splitting.Herein,we summarized the latest studies conducted on bismuth-based photoelectrodes for photoelectrochemical water splitting.Specifically,photoelectrochemical properties of copper bismuth oxide(CuBi_(2)O_(4)),bismuth ferrites(BiFeO_(3),Bi_(2)Fe_(4)O_(9)),bismuth vanadate(BiVO_(4)),bismuth tungstate(Bi_(2)WO_(6)),bismuth molybdate(Bi_(2)MoO_(6))and bismuth oxyhalids(BiOX,X=I,Cl,Br)are presented.Strategies to achieve high stability and photolectrochemical performance were discussed in the aspects of nanostructure formation,heterostructure assembly,practical defect engineering,preferential facet growth and oxygen evolution catalyst incorporation.展开更多
Nitrogen-doped carbon materials as promising oxygen reduction reaction(ORR) electrocatalysts attract great interest in fuel cells and metal-air batteries because of their relatively high activity, high surface area, h...Nitrogen-doped carbon materials as promising oxygen reduction reaction(ORR) electrocatalysts attract great interest in fuel cells and metal-air batteries because of their relatively high activity, high surface area, high conductivity and low cost. To maximize their catalytic efficiency, rational design of efficient electrocatalysts with rich exposed active sites is highly desired. Besides, due to the complexity of nitrogen species, the identification of active nitrogen sites for ORR remains challenging. Herein, we develop a facile and scalable template method to construct high-concentration nitrogen-doped carbon hollow frameworks(NC), and reveal the effect of different nitrogen species on theirORRactivity on basis of experimental analysis and theoretical calculations. The formation mechanism is clearly revealed, including low-pressure vapor superassembly of thin zeolitic imidazolate framework(ZIF-8) shell on ZnO templates,in situ carbonization and template removal. The obtained NC-800 displays better ORR activity compared with other NC-700 and NC-900 samples. Our results indicate that the superior ORR activity of NC-800 is mainly attributed to its content balance of three nitrogen species. The graphitic N and pyrrolic N sites are responsible for lowering the working function, while the pyridinic N and pyrrolic N sites as possible active sites are beneficial for increasing the density of states.展开更多
Aluminum-ion batteries(AIBs)are promising next-generation batteries systems because of their features of low cost and abundant aluminum resource.However,the inferior rate capacity and poor all-climate performance,espe...Aluminum-ion batteries(AIBs)are promising next-generation batteries systems because of their features of low cost and abundant aluminum resource.However,the inferior rate capacity and poor all-climate performance,especially the decayed capacity under low temperature,are still critical challenges toward high-specific-capacity AIBs.Herein,we report a binder-free and freestanding metal-organic framework-derived FeS_(2)@C/carbon nanotube(FeS_(2)@C/CNT)as a novel all-climate cathode in AIBs working under a wide temperature window between−25 and 50℃ with exceptional flexibility.The resultant cathode not only drastically suppresses the side reaction and volu-metric expansion with high capacity and long-term stability but also greatly enhances the kinetic process in AIBs with remarkable rate capacity(above 151 mAh g^(−1) at 2 A g^(−1))at room temperature.More importantly,to break the bottleneck of the inherently low capacity in graphitic material-based all-climate AIBs,the new hierarchical conductive composite FeS_(2)@C/CNT highly promotes the all-climate performance and delivers as high as 117 mAh g^(−1) capacity even under−25°C.The well-designed metal sulfide electrode with remarkable performance paves a new way toward all-climate and flexible AIBs.展开更多
The rapidly increasing demand for wearable electronic devices has motivated research in low-cost and flexible printed batteries with diverse form factors and architectures.In the past,technological achieve-ments in th...The rapidly increasing demand for wearable electronic devices has motivated research in low-cost and flexible printed batteries with diverse form factors and architectures.In the past,technological achieve-ments in the field have been emphasized,overlooking the industrial and market requirements.However,different applications require different battery chemistries and formats,that greatly impacts the manu-facturing process and competition landscape.These chemistries and formats should therefore be selected carefully to maximize the chances for commercial success.As some of these technologies are starting to be marketed for portable electronics,there is a pressing need to evaluate different printing technologies and compare them in terms of the processing constraints and product requirements of specific electronic devices.By evaluating the intrinsic strengths and current limitations of printed battery technologies,development pathways can be prioritized,and potential bottlenecks can be overcome to accelerate the path to market.展开更多
A renewable energy supply is an integral part of a sustainable society.The most abundant and widespread renewable energy source available on the earth,i.e.,sunlight,is intermittent and has a low energy density.This ma...A renewable energy supply is an integral part of a sustainable society.The most abundant and widespread renewable energy source available on the earth,i.e.,sunlight,is intermittent and has a low energy density.This makes an economical and efficient technology to convert and store the solar energy necessary in order to utilise it on our path towards a low carbon economy.Photocatalysis and photo‐electrocatalysis can in principle store renewable solar energy into chemical bonds by diverse chemical processes,including water splitting to H_(2),nitrogen reduction to ammonia,CO_(2) reduction to chemicals and others.These chemical processes physically involve charge generation,charge separation and transfer,chemically include two half reactions and generally share the very sluggish water oxidation half reaction.The persistent kinetic challenges of these complex photophysical and photochemical processes have kept solar to fuel conversion efficiency as very moderate.展开更多
Development of low-cost and efficient photocatalytic materials with visible-light response is of urgent need for solving energy and environmental problems.Here,a metal-free two-dimensional(2D)π-conjugated hybrid g-C_...Development of low-cost and efficient photocatalytic materials with visible-light response is of urgent need for solving energy and environmental problems.Here,a metal-free two-dimensional(2D)π-conjugated hybrid g-C_(3)N_(4)photocatalyst with tunable band structure was prepared by a novel one-pot bottom-up method based on a supersaturated precipitation process of urea and triethanolamine(TEOA)solution.The microstructure of the hybrid g-C_(3)N_(4)is revealed to be a compound of periodic tri-s-triazine units grafted with N-doped graphene(GR)fragments.From experimental evidence and theoretical calculations,the two differentπ-conjugated fragments in the hybrid g-C_(3)N_(4)material are proved to construct a 2D in-plane junction structure,thereby expanding the light absorption range and accelerating the interface charge transfer.Theπ-conjugated electron coupling in the 2D photocatalyst eliminates the grain boundary effect,and the coupled highest occupied molecular orbital(HOMO)effectively promotes the separation of photo-induced charge carriers.Compared with the g-C_(3)N_(4)prepared by the conventional method,the visible-light H2 production activity of the optimized sample is enhanced by 253%.This work provides a new strategy of constructing metal-free g-C_(3)N_(4)hybrids for efficient photocatalytic water splitting.展开更多
Graphitic carbon nitride(g-C3N4,CN)exhibits inefficient charge separation,deficient CO2 adsorption and activation sites,and sluggish surface reaction kinetics,which have been recognized as the main barriers to its app...Graphitic carbon nitride(g-C3N4,CN)exhibits inefficient charge separation,deficient CO2 adsorption and activation sites,and sluggish surface reaction kinetics,which have been recognized as the main barriers to its application in CO2 photocatalytic reduction.In this work,carbon quantum dot(CQD)decoration and oxygen atom doping were applied to CN by a facile one-step hydrothermal method.The incorporated CQDs not only facilitate charge transfer and separation,but also provide alternative CO2 adsorption and activation sites.Further,the oxygen-atom-doped CN(OCN),in which oxygen doping is accompanied by the formation of nitrogen defects,proves to be a sustainable H^+ provider by facilitating the water dissociation and oxidation half-reactions.Because of the synergistic effect of the hybridized binary CQDs/OCN addressing the three challenging issues of the CN based materials,the performance of CO2 photocatalytic conversion to CH4 over CQDs/OCN-x(x represents the volume ratio of laboratory-used H2O2(30 wt.%)in the mixed solution)is dramatically improved by 11 times at least.The hybrid photocatalyst design and mechanism proposed in this work could inspire more rational design and fabrication of effective photocatalysts for CO2 photocatalytic conversion with a high CH4 selectivity.展开更多
基金financially supported by the National Key Research and Development Program(Nos.2022YFB2502104 and 2022YFA1602700)the Key Research and Development Program of Jiangsu Provincial Department of Science and Technology of China(No.BE2022332)+4 种基金the Jiangsu Carbon Peak Carbon Neutralization Science and Technology Innovation Special Fund(No.BE2022605)the National Natural Science Foundation of China(Nos.22109073,22379071)the DECRA program of Australian Research Council(No.DE230100357)the JSPS KAKENHI(No.JP23K13703)the Center for Computational Materials Science,Institute for Materials Research,Tohoku University for the use of MASAMUNE-IMR(202312-SCKXX-0203)。
文摘Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electrocatalysts with high SSA and optimized structure is of great significance but remains a tremendous challenge.Herein,we propose a general strategy for fabrication of mesoporous perovskite oxide nanosheets(MPONs)with controllable atomic doping via self-sacrificial template-induced nanostructure modulation.A variety of MPONs including LaFeO_(3),A-site-doped LaFeO_(3)(A-LaFeO_(3),where A is Pr,Nd,Sm,Eu,or Gd)and B-site-doped LaFeO_(3)(B-LaFeO_(3),where B is Mn,Co,Ni,Cu,or Zn)have been achieved.Interestingly,it is discovered that the catalytic activities of A-LaFeO_(3) MPONs as OER catalysts are overall higher than those of B-LaFeO_(3) ones.Especially,the screened Eu-LaFeO_(3) MPONs only require a low overpotential of 267 mV at 10 mA cm^(−2),outperforming most reported perovskite oxides.The superior catalytic activity of Eu-LaFeO_(3) MPONs is attributed to their favorable porous structure,which increases the density of active sites,and enhanced lattice oxygen participation,which improves the intrinsic activity.This study provides guidance for the design and controlled synthesis of advanced rare-earth-doped MPONs with ultrahigh SSA for enhanced electrocatalysis.
基金supported by the National Natural Science Foundation of China(No.U2130128)Yanzhao Young Scientist Project from Natural Science Foundation of Hebei Province(Nos.B2023205040)+4 种基金Basic Research Cooperation Special Foundation of Beijing-Tianjin-Hebei Region(Nos.H2022205047,22JCZXJC00060 and E3B33911DF)Hebei Administration for Market Supervision Science and Technology Project List(No.2023ZC03)the Innovation Capability Improvement Plan Project of Hebei Province(No.22567604H)Ph.D.Scientific Research Start-up Fund of Hebei Normal University(No.L2023B18)College Student’s Innovation and Entrepreneurship Training Plan Program(No.S202410094046).
文摘Additive engineering significantly enhances the photovoltaic performance of perovskite solar cells(PSCs).The atomistic and mechanistic origins of these jfurther investigation to fully understand the physicochemical interactions of additives with the perovskite lattice,band structure,and charge carriers.Herein,how additives of cellulose triacetate(CTA)improve the photovoltaic performance and stability of perovskite solar cells(PSCs)is shown.These improvements are found to stem from the formation of hydrogen bonds between CTA molecules and organic cations.The Kelvin probe force microscopy results show that contact potential difference variation under dark and light conditions increases from 79.68 to 141.24 mV by doping CTA,indicating enhanced separation of electron-hole pairs in perovskite.The piezoresponse force microscopy(PFM)tests indicate that CTA additives reduce the PFM amplitude by approximately 50 pm under dark and light conditions and inhibit flipping from antiferroelectric domains to ferroelectric domains.Moreover,the CTA additives regulate the charge distribution within the PbI6 octahedron and bind organic ions through hydrogen bonding,forming a compact film structure.These findings not only improve the long-term stability of organic-inorganic hybrid perovskites(OIHPs),but also pave the way for developing novel strategies for large-scale PSCs.
基金the financial support from Australian Research Council through its DP and FF programsthe support from IPRS and UQ Centennial Scholarships
文摘Photocatalysis has attracted much attention in recent years due to its potential in solving energy and environmental issues. Even though numerous achievements have been made, the photocatalytic systems developed to date are still far from practical applications due to the low efficiency and poor durability. Efficient light absorption and charge separation are two of the key factors for the exploration of high performance photocatalytic systems, which is generally difficult to be obtained in a single photocata- lyst. The combination of various materials to form heterojunctions provides an effective way to better harvest solar energy and to facilitate charge separation and transfer, thus enhancing the photocatalytic activity and stability. This review concisely summarizes the recent development of visible light respon- sive heterojunctions, including the preparation and performances of semiconductor/semiconductor junctions, semiconductor/cocatalyst junctions, semiconductor/metal junctions, semiconductor/non- metal junctions, and surface heterojunctions, and their mechanism for enhanced light harvesting and charge separation/transfer.
基金support from the Australian Research Council through its DECRA(DE210100930)Discovery Project (DP200101900)+2 种基金Lau-reate Fellowship (FL190100139) schemesfinancial support from Research Donation Generic(2020003431) from the Faculty of EngineeringArchitecture and Information Technology,The University of Queensland
文摘As a kind of valuable chemicals,hydrogen peroxide(H2O2)has aroused growing attention in many fields.However,H2O2 production via traditional anthraquinone process suffers from challenges of large energy consumption and heavy carbon footprint.Alternatively,photoelectrocatalytic(PEC)production of H2O2 has shown great promises to make H2O2 a renewable fuel to store solar energy.Transition‐metal‐oxide(TMO)semiconductor based photoelectrocatalysts are among the most promising candidates for PEC H2O2 production.In this work,the fundamentals of H2O2 synthesis through PEC process are briefly introduced,followed by the state‐of‐the‐art of TMO semiconductor based photoelectrocatalysts for PEC production H2O2.Then,the progress on H2O2 fuel cells from on‐site PEC production is presented.Furthermore,the challenges and future perspectives of PEC H2O2 production are discussed.This review aims to provide inspiration for the PEC production of H2O2 as a renewable solar fuel.
文摘Photoelectrochemical(PEC)water splitting process is regarded as a promising route to generate hydrogen by solar energy and at the heart of PEC is efficient electrode design.Great progress has been achieved in the aspects of material design,cocatalyst study,and electrode fabrication over the past decades.However,some key challenges remain unsolved,including the most demanded conversion efficiency issue.As three critical steps,i.e.light harvesting,charge transfer and surface reaction of the PEC process,occur in a huge range of time scale(from10-12s to100s),how to manage these subsequent steps to facilitate the seamless cooperation between each step to realize efficient PEC process is essentially important.This review focuses on an integral consideration of the three key criteria based on the recent progress on high efficient and stable photoelectrode design in PEC.The basic principles and potential strategies are summarized.Moreover,the challenge and perspective are also discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 21975286 and 21473254)the Special Project Fund of “Taishan Scholar” of Shandong Province (Grant No. ts201511017)+2 种基金the QLUT Special Funding for Distinguished Scholars (Grant No. 2419010420)the project ZR2020QE058 supported by Shandong Provincial Natural Science Foundationthe Fundamental Research Funds for the Central Universities (Grant Nos. YCX2020050,18CX06030A,and 17CX02039A)。
文摘The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulating their catalytic sites are a significant challenge in this field. Here,we propose an electrochemical surface restructuring strategy to design synergistically interactive phosphorus-doped carbon@MoP electrocatalysts for the HER. A simple electrochemical cycling method is developed to tune the thickness of the carbon layers that cover on MoP core,which significantly influences HER performance. Experimental investigations and theoretical calculations indicate that the inactive surface carbon layers can be removed through electrochemical cycling,leading to a close bond between the MoP and a few layers of coated graphene. The electronsdonated by the MoP core enhance the adhesion and electronegativity of the carbon layers;the negatively charged carbon layers act as an active surface. The electrochemically induced optimization of the surface/interface electronic structures in the electrocatalysts significantly promotes the HER. Using this strategy endows the catalyst with excellent activity in terms of the HER in both acidic and alkaline environments(current density of 10 mA cm^(-2) at low overpotentials,of 68 mV in 0.5 M H_(2)SO_(4) and 67 mV in 1.0 M KOH).
基金support funding is from the National Natural Science Foundation of China(51871119 and 51901100)China Jiangsu Specially Appointed Professor,Jiangsu Provincial Founds for Natural Science Foundation(BK20170793 and BK20180015)+2 种基金China Postdoctoral Science Foundation(2018M640481 and 2019T120426)Jiangsu Postdoctoral Research Fund(2019K003 and 2019K201)Jiangsu-Innovate UK Business Competition(BZ2017061)
文摘Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this work,two-dimensional(2D)ultrathin FePS3 nanosheets,a typical ternary metal phosphosulfide,are first prepared by ultrasonic exfoliation.The novel 2D/2D heterojunction of FePS3 nanosheets@MXene composite is then successfully synthesized by in situ mixing ultrathin MXene nanosheets with FePS3 nanosheets.The resultant FePS3 nanosheets@MXene hybrids can increase the electronic conductivity and specific surface area,assuring excellent surface and interfacial charge transfer abilities.Furthermore,the unique heterojunction endows FePS3 nanosheets@MXene composite to promote the diffusion of Na^+ and alleviate the drastic change in volume in the cyclic process,enhancing the sodium storage capability.Consequently,the few-layered FePS3 nanosheets uniformly coated by ultrathin MXene provide an exceptional reversible capacity of 676.1 mAh g^−1 at the current of 100 mA g^−1 after 90 cycles,which is equivalent to around 90.6% of the second-cycle capacity(746.4 mAh g^−1).This work provides an original protocol for constructing 2D/2D material and demonstrates the FePS3@MXene composite as a potential anode material with excellent property for sodium-ion batteries.
基金the Australian Government and University of Queensland for the research training program scholarship and research facilities used in this study.
文摘Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5×10^-30S cm^-1),associated lithium polysulfides(PSs),and their migration from the cathode to the anode.In this study,a separator coated with a Ketjen black(KB)/Nafion composite was used in an LSB with a sulfur loading up to 7.88 mg cm^-2to mitigate the PS migration.A minimum specific capacity(Cs)loss of 0.06%was obtained at 0.2 C-rate at a high sulfur loading of 4.39 mg cm^-2.Furthermore,an initial areal capacity up to 6.70 mAh cm^-2 was obtained at a sulfur loading of 7.88 mg cm^-2.The low Cs loss and high areal capacity associated with the high sulfur loading are attributed to the large surface area of the KB and sulfonate group(SO3^-)of Nafion,respectively,which could physically and chemically trap the PSs.
基金financially supported by Australian Research Council through its Discovery and Linkage Programs
文摘Li-rich materials,due to their high capacity(>250 mAh·g^(-1)),have recently been considered as an alternative to the current generation of cathode materials for Li-ion batteries(LIBs).However,their inferior cycling stability limits their practical applicability.Doping is a common technique to solve this problem.However,anion doping remains relatively underexplored.Fluorine(F)is one of the most effective anion dopants owning to the improved capacity,cycling stability,and rate performance in batteries.The explanations and experimental results,however,vary significantly from study to study.Herein,we find that bulk F-doping significantly improves both rate performance and cycling stability,likely driven by charge compensation and greater electronegativity.Additionally,bulk F-doping occasionally improves capacity via enhanced activation and occasionally decreases capacity by preventing activation from occurring.Surface F-doping has similar effects to bulk F-doping on capacity and stability,while significantly hindering the rate performance.Furthermore,the improvements in surface-doped materials do not appear to be a result of specific surface modification,and instead can be ascribed to the effect of fluorine on the near-surface bulk material.Greater understanding of fluo-rine's influence on activation,in particular,is required to unlock the full potential of synergistic cation/anion co-doping.
文摘The lithium sulfur batteries(LSBs) are considered as one of the promising next generation energy storage devices due to the high theoretical specific capacity of sulfur(1675 m Ah g-1), naturally available, low cost.However, the practical LSBs are impeded by the well-known "shuttle effect" combined with other technical drawbacks. The "shuttle effect" causes rapid capacity decay, severe self-discharging and low active material utilization. The polysulfide(PS) which has lone pair electrons in each sulfur atom is considered as Lewis base and shows strong affinity to various polar, Lewis acid and catenation interactive materials but very weakly interacts with the non-polar conductive carbons. The "shuttle effect" occurs due to the diffusion of high order PS from the cathode to the anode and then low-order PS back to the cathode. The PS is polar and, due to a lone pair of electrons associated with the sulfur atom, is considered a Lewis base. As such, the PS shows a strong affinity with various polar and Lewis acid materials. In addition, a more novel trapping can be performance through a catenation reaction. For LSBs to compete with the state-of-the-art lithium ion batteries(LIBs), the LSB areal capacity need to be ~6 m Ah cm-2(which is proportional to sulfur loading). To achieve this target the PS shuttling needs to mitigate, which can be achieved through using functional materials. This review addresses the aforementioned phenomena by considering the PS phase interacts with the various functional materials and how this impacts areal capacity and cycling stability of LSBs.
基金financial support from the National Natural Science Foundation of China(No.52002328)the Fundamental Research Funds for the Central Universities+1 种基金the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z018)the Australian Research Council through its Discovery Projects(DPs)and Laureate Fellowship。
文摘Here we report a new one-step thermal polycondensation process to form crinkly graphitic carbon nitride nanosheets(CGCNNs)via supramolecular preorganization,using a mixture of urea and melamine as the starting material.Systematical studies reveal that the newly developed CGCNNs significantly strengthen the optical absorption,widen the bandgap,and increase the Hall mobility and carrier density compared to that of its bulk counterpart,regardless of the similar chemical composition and structure.As a result,the photocatalytic hydrogen production rate is improved by 7 times.Moreover,Na doping of CGCNNs can further promote its photocatalytic activity,leading to an excellent photocatalytic hydrogen production rate of 250.9μmol h^(–1),which is approximately 10.5 times higher than its bulk counterpart.Moreover,an impressive apparent quantum efficiency of 19.12%is achieved at 420 nm.This study provides a facile strategy for the design of efficient low-cost carbon-nitride-based photocatalysts for solar fuel production.
基金the support by Australian Research Council through its DP and DECRA programsthe support from Research Training Program(RTP),University of Queensland for providing financial support through University of Queensland Research Training Tuition Fee Offset and University of Queensland Research Training Stipend。
文摘Photoelectrochemical water splitting is a sustainable path to generate valuable hydrogen using sunlight and water as the only inputs.Despite significant efforts to date,it is still a challenge to achieve photoelectrode with superior performance and long-term stability.Many bismuth-based semiconductor materials have demonstrated excellent visible light harvesting capability and suitable band edge for water splitting.Herein,we summarized the latest studies conducted on bismuth-based photoelectrodes for photoelectrochemical water splitting.Specifically,photoelectrochemical properties of copper bismuth oxide(CuBi_(2)O_(4)),bismuth ferrites(BiFeO_(3),Bi_(2)Fe_(4)O_(9)),bismuth vanadate(BiVO_(4)),bismuth tungstate(Bi_(2)WO_(6)),bismuth molybdate(Bi_(2)MoO_(6))and bismuth oxyhalids(BiOX,X=I,Cl,Br)are presented.Strategies to achieve high stability and photolectrochemical performance were discussed in the aspects of nanostructure formation,heterostructure assembly,practical defect engineering,preferential facet growth and oxygen evolution catalyst incorporation.
基金supported by the National Natural Science Foundation of China (51832004 and 51521001)the National Key Research and Development Program of China (2016YFA0202603)+2 种基金the Natural Science Foundation of Hubei Province (2019CFA001)the Programme of Introducing Talents of Discipline to Universities (B17034)the Yellow Crane Talent (Science & Technology) Program of Wuhan City。
文摘Nitrogen-doped carbon materials as promising oxygen reduction reaction(ORR) electrocatalysts attract great interest in fuel cells and metal-air batteries because of their relatively high activity, high surface area, high conductivity and low cost. To maximize their catalytic efficiency, rational design of efficient electrocatalysts with rich exposed active sites is highly desired. Besides, due to the complexity of nitrogen species, the identification of active nitrogen sites for ORR remains challenging. Herein, we develop a facile and scalable template method to construct high-concentration nitrogen-doped carbon hollow frameworks(NC), and reveal the effect of different nitrogen species on theirORRactivity on basis of experimental analysis and theoretical calculations. The formation mechanism is clearly revealed, including low-pressure vapor superassembly of thin zeolitic imidazolate framework(ZIF-8) shell on ZnO templates,in situ carbonization and template removal. The obtained NC-800 displays better ORR activity compared with other NC-700 and NC-900 samples. Our results indicate that the superior ORR activity of NC-800 is mainly attributed to its content balance of three nitrogen species. The graphitic N and pyrrolic N sites are responsible for lowering the working function, while the pyridinic N and pyrrolic N sites as possible active sites are beneficial for increasing the density of states.
基金financial support for Australian Research Council through its Discovery and Linkage Programsperformed in part at Australian Microscopy&Microanalysis Research Facility at the Centre for Microscopy and Microanalysis,the University of Queensland(UQ)+3 种基金The authors also acknowledge National Natural Science Foundation of China(51901100 and 51871119)Jiangsu Provincial Founds for Natural Science Foundation(BK20180015)China Postdoctoral Science Foundation(2018M640481 and 2019T120426)Jiangsu Postdoctoral Research Fund(2019K003)。
文摘Aluminum-ion batteries(AIBs)are promising next-generation batteries systems because of their features of low cost and abundant aluminum resource.However,the inferior rate capacity and poor all-climate performance,especially the decayed capacity under low temperature,are still critical challenges toward high-specific-capacity AIBs.Herein,we report a binder-free and freestanding metal-organic framework-derived FeS_(2)@C/carbon nanotube(FeS_(2)@C/CNT)as a novel all-climate cathode in AIBs working under a wide temperature window between−25 and 50℃ with exceptional flexibility.The resultant cathode not only drastically suppresses the side reaction and volu-metric expansion with high capacity and long-term stability but also greatly enhances the kinetic process in AIBs with remarkable rate capacity(above 151 mAh g^(−1) at 2 A g^(−1))at room temperature.More importantly,to break the bottleneck of the inherently low capacity in graphitic material-based all-climate AIBs,the new hierarchical conductive composite FeS_(2)@C/CNT highly promotes the all-climate performance and delivers as high as 117 mAh g^(−1) capacity even under−25°C.The well-designed metal sulfide electrode with remarkable performance paves a new way toward all-climate and flexible AIBs.
基金Financial support from the Cooperative Research Centres Projects (CRC-P) grantAustralian Research Council through its Linkage and Laureate Fellowship programs+3 种基金financial support from Advance Queensland Industry Research Fellowships (AQIRF) organized by the Queensland government, Australiafinancial support from the Research Training Program scholarship provided by the Australian government and the Research Higher Degree Top-up scholarship provided by the CRC-Pthe Dow Centre for Sustainable Engineering Innovationthe University of Queensland
文摘The rapidly increasing demand for wearable electronic devices has motivated research in low-cost and flexible printed batteries with diverse form factors and architectures.In the past,technological achieve-ments in the field have been emphasized,overlooking the industrial and market requirements.However,different applications require different battery chemistries and formats,that greatly impacts the manu-facturing process and competition landscape.These chemistries and formats should therefore be selected carefully to maximize the chances for commercial success.As some of these technologies are starting to be marketed for portable electronics,there is a pressing need to evaluate different printing technologies and compare them in terms of the processing constraints and product requirements of specific electronic devices.By evaluating the intrinsic strengths and current limitations of printed battery technologies,development pathways can be prioritized,and potential bottlenecks can be overcome to accelerate the path to market.
文摘A renewable energy supply is an integral part of a sustainable society.The most abundant and widespread renewable energy source available on the earth,i.e.,sunlight,is intermittent and has a low energy density.This makes an economical and efficient technology to convert and store the solar energy necessary in order to utilise it on our path towards a low carbon economy.Photocatalysis and photo‐electrocatalysis can in principle store renewable solar energy into chemical bonds by diverse chemical processes,including water splitting to H_(2),nitrogen reduction to ammonia,CO_(2) reduction to chemicals and others.These chemical processes physically involve charge generation,charge separation and transfer,chemically include two half reactions and generally share the very sluggish water oxidation half reaction.The persistent kinetic challenges of these complex photophysical and photochemical processes have kept solar to fuel conversion efficiency as very moderate.
基金financially supported by National Natural Science Foundation of China(Nos.22002060 and 51872138)Natural Science Foundation of Jiangsu Province(No.BK20181380)+3 种基金Qing Lan Project,Six Talent Peaks Project in Jiangsu Province(No.XCL029)Priority Academic Program Development of the Jiangsu Higher Education Institutions(PAPD)support provided by China Scholarships Council(CSC No.202008320109)China Postdoctoral Science Foundation(No.2020M681564)。
文摘Development of low-cost and efficient photocatalytic materials with visible-light response is of urgent need for solving energy and environmental problems.Here,a metal-free two-dimensional(2D)π-conjugated hybrid g-C_(3)N_(4)photocatalyst with tunable band structure was prepared by a novel one-pot bottom-up method based on a supersaturated precipitation process of urea and triethanolamine(TEOA)solution.The microstructure of the hybrid g-C_(3)N_(4)is revealed to be a compound of periodic tri-s-triazine units grafted with N-doped graphene(GR)fragments.From experimental evidence and theoretical calculations,the two differentπ-conjugated fragments in the hybrid g-C_(3)N_(4)material are proved to construct a 2D in-plane junction structure,thereby expanding the light absorption range and accelerating the interface charge transfer.Theπ-conjugated electron coupling in the 2D photocatalyst eliminates the grain boundary effect,and the coupled highest occupied molecular orbital(HOMO)effectively promotes the separation of photo-induced charge carriers.Compared with the g-C_(3)N_(4)prepared by the conventional method,the visible-light H2 production activity of the optimized sample is enhanced by 253%.This work provides a new strategy of constructing metal-free g-C_(3)N_(4)hybrids for efficient photocatalytic water splitting.
基金the National Natural Science Foundation of China(No.51578488)Zhejiang Provincial “151” Talents Program,the Program for Zhejiang Leading Team of S&T Innovation(No.2013TD07)Changjiang Scholar Incentive Program(Ministry of Education,China,2009)。
文摘Graphitic carbon nitride(g-C3N4,CN)exhibits inefficient charge separation,deficient CO2 adsorption and activation sites,and sluggish surface reaction kinetics,which have been recognized as the main barriers to its application in CO2 photocatalytic reduction.In this work,carbon quantum dot(CQD)decoration and oxygen atom doping were applied to CN by a facile one-step hydrothermal method.The incorporated CQDs not only facilitate charge transfer and separation,but also provide alternative CO2 adsorption and activation sites.Further,the oxygen-atom-doped CN(OCN),in which oxygen doping is accompanied by the formation of nitrogen defects,proves to be a sustainable H^+ provider by facilitating the water dissociation and oxidation half-reactions.Because of the synergistic effect of the hybridized binary CQDs/OCN addressing the three challenging issues of the CN based materials,the performance of CO2 photocatalytic conversion to CH4 over CQDs/OCN-x(x represents the volume ratio of laboratory-used H2O2(30 wt.%)in the mixed solution)is dramatically improved by 11 times at least.The hybrid photocatalyst design and mechanism proposed in this work could inspire more rational design and fabrication of effective photocatalysts for CO2 photocatalytic conversion with a high CH4 selectivity.
