The ferrocene(Fc)-based metal-organic frameworks(MOFs)are regarded as compelling platforms for the construction of efficient and robust oxygen evolution reaction(OER)electrocatalysts due to their superior conductivity...The ferrocene(Fc)-based metal-organic frameworks(MOFs)are regarded as compelling platforms for the construction of efficient and robust oxygen evolution reaction(OER)electrocatalysts due to their superior conductivity and flexible electronic structure.Herein,density functional theory simulations were addressed to predict the electronic structure regulations of CoFc-MOF by nickel doping,which demonstrated that the well-proposed CoNiFc-MOFs delivered a small energy barrier,promoted conductivity,and well-regulated d-band center.Inspired by these,a series of sea-urchin-like CoNiFc-MOFs were successfully synthesized via a facile solvothermal method.Moreover,the synchrotron X-ray and X-ray photoelectron spectroscopy measurements manifested that the introduction of nickel could tailor the electronic structure of the catalyst and induce the directional transfer of electrons,thus optimizing the rate-determining step of^(*)O→^(*)OOH during the OER process and yielding decent overpotentials of 209 and 252 mV at 10 and 200 mA cm^(−2),respectively,with a small Tafel slope of 39 mV dec^(−1).This work presents a new paradigm for developing highly efficient and durable MOF-based electrocatalysts for OER.展开更多
Moiré superlattices have emerged as a highly controllable quantum platform for exploration of various fascinating phenomena,such as Mott insulator states,ferroelectric order,unconventional superconductivity and o...Moiré superlattices have emerged as a highly controllable quantum platform for exploration of various fascinating phenomena,such as Mott insulator states,ferroelectric order,unconventional superconductivity and orbital ferromagnetism.Although remarkable progress has been achieved,current research in moiré physics has mainly focused on the single species properties,while the coupling between distinct moiré quantum phenomena remains elusive.Here we demonstrate,for the first time,the strong coupling between ferroelectricity and correlated states in a twisted quadrilayer MoS2moiré superlattice,where the twist angles are controlled in sequence to be ~57°,~0°,and ~-57°.Correlated insulator states are unambiguously established at moiré band filling factors v = 1,2,3 of twisted quadrilayer MoS_(2).Remarkably,ferroelectric order can occur at correlated insulator states and disappears quickly as the moiré band filling deviates from the integer fillings,providing smoking gun evidences of the coupling between ferroelectricity and correlated states.Our results demonstrate the coupling between different moiré quantum properties and will hold great promise for new moiré physics and applications.展开更多
Constructed wetlands with Cyperus altrnlifolius,Pennisetum sinese Roxb and elephant grass as vegetation were built to study the nitrogen and phosphorous removal from domestic sewage in cold climate.It was found that t...Constructed wetlands with Cyperus altrnlifolius,Pennisetum sinese Roxb and elephant grass as vegetation were built to study the nitrogen and phosphorous removal from domestic sewage in cold climate.It was found that these three plants could all grow slowly and stably under low temperature stress in winter,and the biomass,nitrogen and phosphorus absorption characteristics and absorbing capacity of the three plants were different.The growth rate and biomass were as follows:P.sinese Roxb>elephant grass>C.altrnlifolius,and these three plants could be used as winter wetland decontamination plants in Southwest China;the absorption characteristics of nitrogen and phosphorus in different tissues of the three plants were as follows:nitrogen content in leaf>nitrogen content in stem,phosphorus content in stem>phosphorus content in leaf;the removal of total nitrogen(TN)by three plants in the wetland was ranged form 4.3%to 7.8%,and the removal of total phosphorus(TP)was ranged from 3.3%to 5.3%.Different plants had different absorption effects on nitrogen and phosphorus.There was a significantly positive correlation between plant nitrogen and phosphorus accumulation and biomass,and nitrogen removal rate in wetland showed a significantly positive correlation with biomass.展开更多
Alloying strategies provide a high degree of freedom for reducing lead toxicity,improving thermodynamic stability, tuning the optoelectronic properties of ABX3 halide perovskites by varying the alloying element specie...Alloying strategies provide a high degree of freedom for reducing lead toxicity,improving thermodynamic stability, tuning the optoelectronic properties of ABX3 halide perovskites by varying the alloying element species and their contents.Given the key role of B-site cations in contributing band edge states and modulating structure factors in halide perovskites,the partial replacement of Pb2+with different B-site metal ions has been proposed.Although several experimental attempts have been made to date,the effect of B-site alloying on the stability and electronic properties of halide perovskites has not been fully explored.Herein,we take cubic CsPbBr3 perovskite as the prototype material and systematically explore the effects of B-site alloying on Pb-containing perovskites.According to the presence or absence of the corresponding perovskite phase,the ten alloying elements investigated are classified into three types(i.e.,Type Ⅰ:Sn Ge,Ca,Sr;Type Ⅱ:Cd,Mg,Mn;Type Ⅲ:Ba,Zn,Cu).Based on the first-principles calculations,we obtain the following conclusions.First,these B-site alloys will exist as disordered solid solutions rather than ordered structures at room temperature throughout the composition space.Second,the alloying of Sn and Ge enhances the thermodynamic stability of the cubic perovskite host,whereas the alloying of the other elements has no remarkable effect on the thermodynamic stability of the cubic perovskite host.Third,the underlying physical mechanism for bandgap tuning can be attributed to the atomic orbital energy mismatch or quantum confinement effect.Fourth,the alloying of different elements demonstrates the diversity in the regulation of crystal structure and electronic properties,indicating potential applications in photovoltaic s and self-trapped exciton-based light-emitting applications.Our work provides theoretical guidance for using alloying strategies to reduce lead toxicity,enhance stability,and optimize the electronic properties of halide perovskites to meet the needs of optoelectronic applications.展开更多
Formamidinium lead triiodide(HC(NH2)2PbI3 or FAPbI3)is a promising light absorber for high-efficiency perovskite solar cells because of its superior light absorption range and thermal stability to CH3NH3PbI3(MAPbI3).U...Formamidinium lead triiodide(HC(NH2)2PbI3 or FAPbI3)is a promising light absorber for high-efficiency perovskite solar cells because of its superior light absorption range and thermal stability to CH3NH3PbI3(MAPbI3).Unfortunately,it is difficult to fabricate high-quality FAPbI3 thin films to surpass the MAPbI3-based cells due to easily forming unwanted but more stable yellow d-phase and thus requiring high annealing-temperature for wanted photovoltaic-active black a-phase.Herein,we reported a novel low-temperature fabrication of highly crystallized a-FAPbI3 film exhibiting uniaxial-oriented nature with large grain sizes up to 2 lm.First-principles energetic calculations predicted that this novel deposition should be ascribed to the formation of a high-energy metastable two-dimensional(2D)intermediate of MAFAPbI3 Cl followed by a spontaneous conversion to a-FAPbI3.The ions exchange reaction during this MAFAPbI3 Cl-FAPbI3 conversion account for the perovskite film uniaxial-oriented grown along the(111)direction.This large-grain and uniaxial-oriented grown a-FAPbI3 based solar cells exhibited an efficiency up to 20.4%accompanying with low density-voltage(J-V)hysteresis and high stability.展开更多
This study investigated the physical(L*,a*,b*,texture profile analyses,pH),chemical(TVB-N,K value and TBA),microbiological,amino acid content,and flavor effects that Gingko biloba leaf extract(GBLE)had on silver pomfr...This study investigated the physical(L*,a*,b*,texture profile analyses,pH),chemical(TVB-N,K value and TBA),microbiological,amino acid content,and flavor effects that Gingko biloba leaf extract(GBLE)had on silver pomfret(Pampus argenteus)stored at 4±1C in ice for 18 days.Fresh pomfret samples were obtained directly from the local fish market and transported to the laboratory with ice immediately.After being gutted,washed,filleted and trimmed in a water-ice mixture,samples were treated with different concentrations of GBLE(0.0 mg/mL,2.5 mg/mL,5.0 mg/mL,10.0 mg/mL)and packaged in Polyethylene bag,then stored in a refrigerator at 4±1C with ice.The results show that the shelf-life of untreated(0.0 mg/mL)pomfret samples was 8e9 days compared to 14e15 days for the GBLE1(2.5 mg/mL)treated group.The assessment results showed that different concentrations of GBLE had variable effects on preserving the texture parameters of acceptability limit,inhibit lipid oxidation,protein degradation,and microorganism growth.2.5 mg/mL of GBLE was the best for the preservation of pomfret during storage in ice.Therefore,there is potential use for GBLE as a preservative to extend the shelf-life of pomfret during chilled storage in ice.展开更多
基金Changjiang Scholars Program of the Ministry of Education,Grant/Award Number:Q2018270Outstanding Youth Funding of Anhui Province,Grant/Award Number:OUFAH 1908085J10+2 种基金Jiangsu Students'Innovation and Entrepreneurship Training Program,Grant/Award Number:202111117079YNatural Science Foundation of Jiangsu Province,Grant/Award Number:BK20200044National Natural Science Foundation of China,Grant/Award Numbers:NSFC 21671004,NSFC 21975001,NSFC U1904215。
文摘The ferrocene(Fc)-based metal-organic frameworks(MOFs)are regarded as compelling platforms for the construction of efficient and robust oxygen evolution reaction(OER)electrocatalysts due to their superior conductivity and flexible electronic structure.Herein,density functional theory simulations were addressed to predict the electronic structure regulations of CoFc-MOF by nickel doping,which demonstrated that the well-proposed CoNiFc-MOFs delivered a small energy barrier,promoted conductivity,and well-regulated d-band center.Inspired by these,a series of sea-urchin-like CoNiFc-MOFs were successfully synthesized via a facile solvothermal method.Moreover,the synchrotron X-ray and X-ray photoelectron spectroscopy measurements manifested that the introduction of nickel could tailor the electronic structure of the catalyst and induce the directional transfer of electrons,thus optimizing the rate-determining step of^(*)O→^(*)OOH during the OER process and yielding decent overpotentials of 209 and 252 mV at 10 and 200 mA cm^(−2),respectively,with a small Tafel slope of 39 mV dec^(−1).This work presents a new paradigm for developing highly efficient and durable MOF-based electrocatalysts for OER.
基金supported by the Key-Area Research and Development Program of Guangdong Province,China (Grant No.2020B0101340001)the National Key Research and Development Program of China (Grant Nos.2021YFA1202900 and 2020YFA0309600)+4 种基金the National Science Foundation of China (Grant Nos.61888102,11834017,1207441,and 12274447)the Strategic Priority Research Program of CAS(Grant Nos.XDB30000000 and XDB33000000)the supports from the Elemental Strategy Initiative conducted by the MEXT,Japan(Grant No.JPMXP0112101001)JSPS KAKENHI(Grant Nos.19H05790,20H00354,and 21H05233)A3 Foresight by JSPS。
文摘Moiré superlattices have emerged as a highly controllable quantum platform for exploration of various fascinating phenomena,such as Mott insulator states,ferroelectric order,unconventional superconductivity and orbital ferromagnetism.Although remarkable progress has been achieved,current research in moiré physics has mainly focused on the single species properties,while the coupling between distinct moiré quantum phenomena remains elusive.Here we demonstrate,for the first time,the strong coupling between ferroelectricity and correlated states in a twisted quadrilayer MoS2moiré superlattice,where the twist angles are controlled in sequence to be ~57°,~0°,and ~-57°.Correlated insulator states are unambiguously established at moiré band filling factors v = 1,2,3 of twisted quadrilayer MoS_(2).Remarkably,ferroelectric order can occur at correlated insulator states and disappears quickly as the moiré band filling deviates from the integer fillings,providing smoking gun evidences of the coupling between ferroelectricity and correlated states.Our results demonstrate the coupling between different moiré quantum properties and will hold great promise for new moiré physics and applications.
基金Supported by Guizhou Tripartite Joint Fund(Qiankehe LH[2016]7283)Top Talent Project of Guizhou Province(Qianjiaohe KY[2016]097)Doctoral Research Start up Fund of Anshun University[(asubsjj 2016)07].
文摘Constructed wetlands with Cyperus altrnlifolius,Pennisetum sinese Roxb and elephant grass as vegetation were built to study the nitrogen and phosphorous removal from domestic sewage in cold climate.It was found that these three plants could all grow slowly and stably under low temperature stress in winter,and the biomass,nitrogen and phosphorus absorption characteristics and absorbing capacity of the three plants were different.The growth rate and biomass were as follows:P.sinese Roxb>elephant grass>C.altrnlifolius,and these three plants could be used as winter wetland decontamination plants in Southwest China;the absorption characteristics of nitrogen and phosphorus in different tissues of the three plants were as follows:nitrogen content in leaf>nitrogen content in stem,phosphorus content in stem>phosphorus content in leaf;the removal of total nitrogen(TN)by three plants in the wetland was ranged form 4.3%to 7.8%,and the removal of total phosphorus(TP)was ranged from 3.3%to 5.3%.Different plants had different absorption effects on nitrogen and phosphorus.There was a significantly positive correlation between plant nitrogen and phosphorus accumulation and biomass,and nitrogen removal rate in wetland showed a significantly positive correlation with biomass.
基金supported by the National Natural Science Foundation of China(Grant Nos.12004131,and 22090044)the Jilin Province Science and Technology Development Program(Grant No.20210508044RQ)。
文摘Alloying strategies provide a high degree of freedom for reducing lead toxicity,improving thermodynamic stability, tuning the optoelectronic properties of ABX3 halide perovskites by varying the alloying element species and their contents.Given the key role of B-site cations in contributing band edge states and modulating structure factors in halide perovskites,the partial replacement of Pb2+with different B-site metal ions has been proposed.Although several experimental attempts have been made to date,the effect of B-site alloying on the stability and electronic properties of halide perovskites has not been fully explored.Herein,we take cubic CsPbBr3 perovskite as the prototype material and systematically explore the effects of B-site alloying on Pb-containing perovskites.According to the presence or absence of the corresponding perovskite phase,the ten alloying elements investigated are classified into three types(i.e.,Type Ⅰ:Sn Ge,Ca,Sr;Type Ⅱ:Cd,Mg,Mn;Type Ⅲ:Ba,Zn,Cu).Based on the first-principles calculations,we obtain the following conclusions.First,these B-site alloys will exist as disordered solid solutions rather than ordered structures at room temperature throughout the composition space.Second,the alloying of Sn and Ge enhances the thermodynamic stability of the cubic perovskite host,whereas the alloying of the other elements has no remarkable effect on the thermodynamic stability of the cubic perovskite host.Third,the underlying physical mechanism for bandgap tuning can be attributed to the atomic orbital energy mismatch or quantum confinement effect.Fourth,the alloying of different elements demonstrates the diversity in the regulation of crystal structure and electronic properties,indicating potential applications in photovoltaic s and self-trapped exciton-based light-emitting applications.Our work provides theoretical guidance for using alloying strategies to reduce lead toxicity,enhance stability,and optimize the electronic properties of halide perovskites to meet the needs of optoelectronic applications.
基金This work was sponsored by the National Natural Science Foundation of China （Nos. 21475021, 21427807, 61722403, 11404131, and 11674121）, the Natural Science Foundation of Jiangsu Province （No. BK20141331）, the Fundamental Research Funds for the Central Universities, Program for JLU Science and Technology Innovative Research Team, the Special Fund for Talent Exploitation in Jilin Province of China, Jiangsu provincial financial support of fundamental conditions and science and technology for people＇s livelihood for Jiangsu key laboratory of advanced metallic materials （No. BM2007204）.
基金the support of the National Natural Science Foundation of China(21777096,51861145101)the support of the National Natural Science Foundation of China(61722403,11674121)+3 种基金Huoyingdong Grant(151046)the National Key Research and Development Program of China(2016YFB0201204)the support of The Initiative Postdocs Supporting Program(BX20180185)China Postdoctoral Science Foundation(2018M640387)
文摘Formamidinium lead triiodide(HC(NH2)2PbI3 or FAPbI3)is a promising light absorber for high-efficiency perovskite solar cells because of its superior light absorption range and thermal stability to CH3NH3PbI3(MAPbI3).Unfortunately,it is difficult to fabricate high-quality FAPbI3 thin films to surpass the MAPbI3-based cells due to easily forming unwanted but more stable yellow d-phase and thus requiring high annealing-temperature for wanted photovoltaic-active black a-phase.Herein,we reported a novel low-temperature fabrication of highly crystallized a-FAPbI3 film exhibiting uniaxial-oriented nature with large grain sizes up to 2 lm.First-principles energetic calculations predicted that this novel deposition should be ascribed to the formation of a high-energy metastable two-dimensional(2D)intermediate of MAFAPbI3 Cl followed by a spontaneous conversion to a-FAPbI3.The ions exchange reaction during this MAFAPbI3 Cl-FAPbI3 conversion account for the perovskite film uniaxial-oriented grown along the(111)direction.This large-grain and uniaxial-oriented grown a-FAPbI3 based solar cells exhibited an efficiency up to 20.4%accompanying with low density-voltage(J-V)hysteresis and high stability.
基金The study was financially supported by China Agriculture Research System(CARS-47),Shanghai promote agriculture by applying scientific&technological advances projects(2015No.4-12),Ability promotion project of Shanghai Municipal Science and Technology Commission Engineering Center(16DZ2280300)Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation(17DZ2293400).
文摘This study investigated the physical(L*,a*,b*,texture profile analyses,pH),chemical(TVB-N,K value and TBA),microbiological,amino acid content,and flavor effects that Gingko biloba leaf extract(GBLE)had on silver pomfret(Pampus argenteus)stored at 4±1C in ice for 18 days.Fresh pomfret samples were obtained directly from the local fish market and transported to the laboratory with ice immediately.After being gutted,washed,filleted and trimmed in a water-ice mixture,samples were treated with different concentrations of GBLE(0.0 mg/mL,2.5 mg/mL,5.0 mg/mL,10.0 mg/mL)and packaged in Polyethylene bag,then stored in a refrigerator at 4±1C with ice.The results show that the shelf-life of untreated(0.0 mg/mL)pomfret samples was 8e9 days compared to 14e15 days for the GBLE1(2.5 mg/mL)treated group.The assessment results showed that different concentrations of GBLE had variable effects on preserving the texture parameters of acceptability limit,inhibit lipid oxidation,protein degradation,and microorganism growth.2.5 mg/mL of GBLE was the best for the preservation of pomfret during storage in ice.Therefore,there is potential use for GBLE as a preservative to extend the shelf-life of pomfret during chilled storage in ice.
