Industrial fly ash-derived SiO2aerogel with abundant mesopores has an excellent ability to support active ingredients for constructing efficient and stable catalyst in electrochemical CO2reduction reaction(CO_(2...Industrial fly ash-derived SiO2aerogel with abundant mesopores has an excellent ability to support active ingredients for constructing efficient and stable catalyst in electrochemical CO2reduction reaction(CO2RR).However,how to select and arrange active sites on its surface poses significant challenges due to its non-conductive nature.Here,we subtly designed and synthesized multi-component architectures to achieve the high efficiency of CO2RR to CO.The embedding of active and amorphous nitrogen-doped carbon(NC)nanosheets on the surface and inside of SiO2aerogel ensures the charge transport on the catalyst surface,and Er2O3improves dissociation of H2O,enabling the supply of protons for CO2RR.Simultaneously,Er2O3-induced defects/vacancies,nanoclusters coordinated with N on amorphous NC and single Ni in NC play crucial role in enhancing adsorption and activation of CO2.Consequently,the Ni-Er2O3/NC-SiO2catalyst exhibits the maintenance of FECOhigher than 95%over a wide potential window(-0.22 to-1.12 V vs.RHE)in a flow cell with gas-liquid-solid electrode.This work not only provides an atomistic understanding of nature of active sites in CO2RR but also contributes to the secondary utilization of industrial fly ash for a carbon-neutral future.展开更多
针对光固化Al2O3陶瓷在脱脂烧结后易形成孔洞、力学性能差的问题,系统研究了石墨烯添加对陶瓷浆料流变性、沉降性、固化行为及烧结体力学性能的影响。采用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)对Al2O3粉体进行表面改性,并加入不同含...针对光固化Al2O3陶瓷在脱脂烧结后易形成孔洞、力学性能差的问题,系统研究了石墨烯添加对陶瓷浆料流变性、沉降性、固化行为及烧结体力学性能的影响。采用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)对Al2O3粉体进行表面改性,并加入不同含量的石墨烯,制备高固相、低粘度的光固化浆料。通过傅里叶红外光谱、旋转流变仪、沉降试验及Beer-Lambert模型分析,优化了浆料配方与光固化工艺参数。结果表明:当KH560含量为2.5wt%、石墨烯含量为0.01wt%时,浆料粘度最低、沉降分层最少;在曝光时间4 s条件下,添加0.01wt%石墨烯的浆料透射深度为382μm,临界曝光能量为44.3 m J/cm2。经1750℃烧结后,陶瓷零件致密度达99.7%,弯曲强度为27.61 MPa,维氏硬度为13.45GPa。石墨烯通过位阻效应及裂纹偏转机制有效促进了烧结致密化并改善了力学性能。本研究为光固化增材制造高致密、高性能氧化铝陶瓷提供了试验依据。展开更多
Sodium-ion batteries(SIBs)are regarded as a promising alternative to lithium-ion batteries for grid-scale energy storage owing to their low cost and sustainability;however,their competitiveness is still limited by rel...Sodium-ion batteries(SIBs)are regarded as a promising alternative to lithium-ion batteries for grid-scale energy storage owing to their low cost and sustainability;however,their competitiveness is still limited by relatively low energy density.Here,we report a scalable Mn-Fe-Ni layered oxide with a compositional-structural dual-gradient(DG)architecture synthesized via a three-step co-precipitation method.By exploiting the opposite roles of high-ionic-potential Mn and low-ionic-potential Fe in stabilizing the P2 and O3 frameworks,respectively,a pure compositional Mn/Fe gradient is translated into a structural P2/O3 gradient with precisely guided synthesis conditions.The Fe-deficient surface effectively suppressed Fe4+-induced side reactions,while the stable P2-type shell and the enlarged R value of the O3 core further enhanced cycling stability during structural evolution.The optimized cathode delivered an energy density of 478 Wh kg-1at 4.2 V,with 82%capacity retention after 200 cycles in half cells and 91%retention after 1600 cycles in full cells.This study demonstrates a viable pathway for developing high-energy-density and long-lifetime cathodes for sodium-ion batteries.展开更多
As an emerging crystalline porous material,hydrogen bonded organic frameworks(HOFs)have enormous potential in photocatalytic field.However,poor stability and rapid recombination of photogenerated charges hinder their ...As an emerging crystalline porous material,hydrogen bonded organic frameworks(HOFs)have enormous potential in photocatalytic field.However,poor stability and rapid recombination of photogenerated charges hinder their practical application in photocatalytic H2O2production.To address the above challenges,this work employs a wet chemical method to grow In2S3nanosheets in situ on the surface of highly stable HOF nanorods(PFC-1),resulting in a novel inorganic/organic In2S3/PFC-1(IP)S-scheme heterojunction.The optimal IP composite achieves a significantly improved photocatalytic H2O2evolution rate of 3.78 mmol g-1h-1,which is 2.9-and 3.7-fold than that of In2S3and PFC-1,respectively.The elevated visible-light absorption,abundant active sites,and effective charge separation of IP S-scheme heterojunction result in the improvement in photocatalytic performance.Additionally,photocatalytic H2O2production of IP goes through a two-electron O2 reduction reaction pathway.This work offers a novel strategy for the fabrication of efficient HOF-based S-scheme heterostructures and their application in photocatalytic field.展开更多
Oxygen deficiency is known to critically influence the superconductivity of La3Ni2O7-δ.However,precise control of oxygen content to mitigate such deficiencies remains a significant challenge.In this work,we ...Oxygen deficiency is known to critically influence the superconductivity of La3Ni2O7-δ.However,precise control of oxygen content to mitigate such deficiencies remains a significant challenge.In this work,we synthesized high-oxygencontent La3Ni2O7+δpolycrystals via high-pressure oxygen annealing with the oxygen stoichiometry(δ)successfully tuned by varying the amount of KClO4.The obtained samples La3Ni2O7.16and La3Ni2O7.38exhibit metallic behavior at ambient pressure.We further conducted a comprehensive investigation into the pressure-induced superconductivity and atomic structure.STEM imaging revealed large-area bilayer-phase stacking in La3Ni2O7.16,while La3Ni2O7.38showed noticeable intergrowth with other Ruddlesden-Popper(R-P)phases.Notably,the critical pressure in La3Ni2O7.16is substantially reduced,though its critical temperature(Tc)is lower than that of as-grown samples.In contrast,only a weak superconducting signal was detected in higher oxygen content sample La3Ni2O7.38likely due to the intergrowth with other R-P phases,nonnegligible interstitial oxygen,or an increased fraction of the tetragonal phase.Our findings provide a viable pathway for optimizing nickelate superconductivity and offer insights into the fundamental mechanisms governing superconductivity in these materials.展开更多
Photocatalytic conversion of carbon dioxide(CO2)to methanol is hindered by inefficient charge separation and complex multielectron pathways.To address these challenges,we report a synergistic catalyst design in whi...Photocatalytic conversion of carbon dioxide(CO2)to methanol is hindered by inefficient charge separation and complex multielectron pathways.To address these challenges,we report a synergistic catalyst design in which cobalt vacancies(VCo)are coupled with indium single atoms(In SAs).VCo sites were precisely constructed on Co3O4nanosheets using a chlorine cold plasma technique,acting as“atomic sockets”that confine In SAs and form a robust In-O-VCo coordination structure.The resulting In/Co3−xO4catalyst delivered a high methanol production rate of 466.7μmol/(g·h)with 92.3%selectivity under simulated solar irradiation,which was eight times greater than that of the vacancy-free catalyst.Mechanistic studies revealed a synergistic functional division:the VCo sites efficiently adsorbed and dissociated H2O to supply protons,whereas the In SAs polarized CO2and stabilized the critical*COOH intermediate.This synergy of strong electronic metal-support interactions improved charge separation and steered the reaction pathway toward methanol,offering a novel atomic-level strategy for designing highly selective CO2photoreduction catalysts.展开更多
基金National Natural Science Foundation of China(22468034,22162019,22261040)Key Research and Development Project of Ordos(YF20240062)Science and Technology Projects of Inner Mongolia Autonomous Region(2021GG0195)。
摘要Industrial fly ash-derived SiO2aerogel with abundant mesopores has an excellent ability to support active ingredients for constructing efficient and stable catalyst in electrochemical CO2reduction reaction(CO2RR).However,how to select and arrange active sites on its surface poses significant challenges due to its non-conductive nature.Here,we subtly designed and synthesized multi-component architectures to achieve the high efficiency of CO2RR to CO.The embedding of active and amorphous nitrogen-doped carbon(NC)nanosheets on the surface and inside of SiO2aerogel ensures the charge transport on the catalyst surface,and Er2O3improves dissociation of H2O,enabling the supply of protons for CO2RR.Simultaneously,Er2O3-induced defects/vacancies,nanoclusters coordinated with N on amorphous NC and single Ni in NC play crucial role in enhancing adsorption and activation of CO2.Consequently,the Ni-Er2O3/NC-SiO2catalyst exhibits the maintenance of FECOhigher than 95%over a wide potential window(-0.22 to-1.12 V vs.RHE)in a flow cell with gas-liquid-solid electrode.This work not only provides an atomistic understanding of nature of active sites in CO2RR but also contributes to the secondary utilization of industrial fly ash for a carbon-neutral future.
摘要针对光固化Al2O3陶瓷在脱脂烧结后易形成孔洞、力学性能差的问题,系统研究了石墨烯添加对陶瓷浆料流变性、沉降性、固化行为及烧结体力学性能的影响。采用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)对Al2O3粉体进行表面改性,并加入不同含量的石墨烯,制备高固相、低粘度的光固化浆料。通过傅里叶红外光谱、旋转流变仪、沉降试验及Beer-Lambert模型分析,优化了浆料配方与光固化工艺参数。结果表明:当KH560含量为2.5wt%、石墨烯含量为0.01wt%时,浆料粘度最低、沉降分层最少;在曝光时间4 s条件下,添加0.01wt%石墨烯的浆料透射深度为382μm,临界曝光能量为44.3 m J/cm2。经1750℃烧结后,陶瓷零件致密度达99.7%,弯曲强度为27.61 MPa,维氏硬度为13.45GPa。石墨烯通过位阻效应及裂纹偏转机制有效促进了烧结致密化并改善了力学性能。本研究为光固化增材制造高致密、高性能氧化铝陶瓷提供了试验依据。
基金National Natural Science Foundation(NNSF)of China(No.52572267)Guangdong Basic and Applied Basic Research Foundation(2023A1515140126)+1 种基金Ministry of Science and Technology of Guangdong Province(2023B0909020001)Guangdong High-level Innovation Institute Project(2021B0909050001)。
摘要Sodium-ion batteries(SIBs)are regarded as a promising alternative to lithium-ion batteries for grid-scale energy storage owing to their low cost and sustainability;however,their competitiveness is still limited by relatively low energy density.Here,we report a scalable Mn-Fe-Ni layered oxide with a compositional-structural dual-gradient(DG)architecture synthesized via a three-step co-precipitation method.By exploiting the opposite roles of high-ionic-potential Mn and low-ionic-potential Fe in stabilizing the P2 and O3 frameworks,respectively,a pure compositional Mn/Fe gradient is translated into a structural P2/O3 gradient with precisely guided synthesis conditions.The Fe-deficient surface effectively suppressed Fe4+-induced side reactions,while the stable P2-type shell and the enlarged R value of the O3 core further enhanced cycling stability during structural evolution.The optimized cathode delivered an energy density of 478 Wh kg-1at 4.2 V,with 82%capacity retention after 200 cycles in half cells and 91%retention after 1600 cycles in full cells.This study demonstrates a viable pathway for developing high-energy-density and long-lifetime cathodes for sodium-ion batteries.
摘要As an emerging crystalline porous material,hydrogen bonded organic frameworks(HOFs)have enormous potential in photocatalytic field.However,poor stability and rapid recombination of photogenerated charges hinder their practical application in photocatalytic H2O2production.To address the above challenges,this work employs a wet chemical method to grow In2S3nanosheets in situ on the surface of highly stable HOF nanorods(PFC-1),resulting in a novel inorganic/organic In2S3/PFC-1(IP)S-scheme heterojunction.The optimal IP composite achieves a significantly improved photocatalytic H2O2evolution rate of 3.78 mmol g-1h-1,which is 2.9-and 3.7-fold than that of In2S3and PFC-1,respectively.The elevated visible-light absorption,abundant active sites,and effective charge separation of IP S-scheme heterojunction result in the improvement in photocatalytic performance.Additionally,photocatalytic H2O2production of IP goes through a two-electron O2 reduction reaction pathway.This work offers a novel strategy for the fabrication of efficient HOF-based S-scheme heterostructures and their application in photocatalytic field.
基金Project supported by the National Key R&D Program of China(Grant No.2022YFA1403203)the National Natural Science Foundation of China(Grant Nos.12204007,12374133,12304162,and 12074002)+5 种基金the Key Scientific Research Foundation of the Education Department of Anhui Province(Grant No.2024AH050046)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302802)Quantum Science and TechnologyNational Science and Technology Major Project(Grant No.2024ZD0301300)the Major Basic Program of Natural Science Foundation of Shandong Province(Grant No.ZR2021ZD01)the Start-up Funding Program of Guangdong-Hong Kong-Macao Greater Bay Area Quantum Science Center(Grant No.QD2301003)Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2401001)。
摘要Oxygen deficiency is known to critically influence the superconductivity of La3Ni2O7-δ.However,precise control of oxygen content to mitigate such deficiencies remains a significant challenge.In this work,we synthesized high-oxygencontent La3Ni2O7+δpolycrystals via high-pressure oxygen annealing with the oxygen stoichiometry(δ)successfully tuned by varying the amount of KClO4.The obtained samples La3Ni2O7.16and La3Ni2O7.38exhibit metallic behavior at ambient pressure.We further conducted a comprehensive investigation into the pressure-induced superconductivity and atomic structure.STEM imaging revealed large-area bilayer-phase stacking in La3Ni2O7.16,while La3Ni2O7.38showed noticeable intergrowth with other Ruddlesden-Popper(R-P)phases.Notably,the critical pressure in La3Ni2O7.16is substantially reduced,though its critical temperature(Tc)is lower than that of as-grown samples.In contrast,only a weak superconducting signal was detected in higher oxygen content sample La3Ni2O7.38likely due to the intergrowth with other R-P phases,nonnegligible interstitial oxygen,or an increased fraction of the tetragonal phase.Our findings provide a viable pathway for optimizing nickelate superconductivity and offer insights into the fundamental mechanisms governing superconductivity in these materials.
基金supported by National Key Research and Development Program(No.2022YFA1504800)National Natural Science Foundation of China(No.22278316).
摘要Photocatalytic conversion of carbon dioxide(CO2)to methanol is hindered by inefficient charge separation and complex multielectron pathways.To address these challenges,we report a synergistic catalyst design in which cobalt vacancies(VCo)are coupled with indium single atoms(In SAs).VCo sites were precisely constructed on Co3O4nanosheets using a chlorine cold plasma technique,acting as“atomic sockets”that confine In SAs and form a robust In-O-VCo coordination structure.The resulting In/Co3−xO4catalyst delivered a high methanol production rate of 466.7μmol/(g·h)with 92.3%selectivity under simulated solar irradiation,which was eight times greater than that of the vacancy-free catalyst.Mechanistic studies revealed a synergistic functional division:the VCo sites efficiently adsorbed and dissociated H2O to supply protons,whereas the In SAs polarized CO2and stabilized the critical*COOH intermediate.This synergy of strong electronic metal-support interactions improved charge separation and steered the reaction pathway toward methanol,offering a novel atomic-level strategy for designing highly selective CO2photoreduction catalysts.