Covalent organic frameworks(COFs)have been developed as the precursors to construct porous carbons for electrocatalytic systems.However,the influences of carbon dimensions on the catalytic performance are still undere...Covalent organic frameworks(COFs)have been developed as the precursors to construct porous carbons for electrocatalytic systems.However,the influences of carbon dimensions on the catalytic performance are still underexplored.In this work,we have first constructed COF-derived carbons by template-synthesis strategy in different dimensions to catalyze the carbon dioxide reduction(CO_(2)RR).By using different templates,the one-dimensional(1D),two-dimensional(2D),and three-dimensional(3D)COF-derived carbons have been employed to anchor Co-porphyrin to form the Co-N5 sites to catalyze CO_(2)RR.The 1D catalyst templated by carbon nano tubes presents high binding ability of CO_(2),more defective sites,and higher electronic conductivity,resulting in a higher catalytic activity for CO_(2)and selectivity of CO than 2D and 3D carbon-based catalysts.The 1D catalyst delivers the turnover frequency values of 1150 h^(−1)and the FECO of 94.5%at 0.7 V versus RHE,which is significantly better than those of 2D and 3D carbon-based catalysts.展开更多
Geological strength index(GSI)has been widely used as an input parameter in predicting the strength and deformation properties of rock masses.This study derived a series of equations to satisfy the original GSI lines ...Geological strength index(GSI)has been widely used as an input parameter in predicting the strength and deformation properties of rock masses.This study derived a series of equations to satisfy the original GSI lines on the basic GSI chart.Two axes ranging from 0 to 100 were employed for surface conditions of the discontinuities and the structure of rock mass,which are independent of the input parameters.The derived equations can analyze GSI values ranging from 0 to 100 within±5%error.The engineering dimensions(EDs)such as the slope height,tunnel width,and foundation width were used together with representative elementary volume(REV)in jointed rock mass to define scale factor(sf)from 0.2 to 1 in evaluating the rock mass structure including joint pattern.The transformation of GSI into a scaledependent parameter based on engineering scale addresses a crucial requirement in various engineering applications.The improvements proposed in this study were applied to a real slope which was close to the time of failure.The results of stability assessments show that the new proposals have sufficient capability to define rock mass quality considering EDs.展开更多
Efficient and selective regeneration of enzymatically active 1,4-NADH from NAD^(+)is pivotal for accelerating photoenzymatic CO_(2)conversion.However,constructing photocatalysts that sustain continuous electron flow a...Efficient and selective regeneration of enzymatically active 1,4-NADH from NAD^(+)is pivotal for accelerating photoenzymatic CO_(2)conversion.However,constructing photocatalysts that sustain continuous electron flow and provide sufficient hydride supply remains a major challenge.Herein,we report a rhodium-coordinated three-dimensional conjugated polymer(3D-Bpy-Rh)photocatalyst featuring multiple electron channels,designed through dimensionality engineering and incorporation of hydride-forming active centers.Such a 3D structure promotes rapid charge separation and multidimensional electron migration,while facilitating trapped-electron release to Rh centers for accelerated electron transfer.As a result,3D-Bpy-Rh achieves a visible-light driven NADH regeneration efficiency of 90.8%with 99.2%selectivity toward 1,4-NADH,surpassing state-of-the-art photocatalysts.Furthermore,the mechanism between the electron reduction capability of the photocatalyst and the selective formation of 1,4-NADH was elucidated,combining transient absorption spectroscopy analysis and DFT calculations.When integrated into photoenzymatic systems,this photocatalyst enhances CO_(2)conversion,boosting methanol and ethanol yields by 5.2-and 2.0-fold,respectively.These results highlighted the potential of dimensionality-engineered photocatalysts for selective 1,4-NADH regeneration and efficient photoenzymatic fuel synthesis.展开更多
Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical...Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical,electronic,and optical properties.This review focuses on the fundamentals of 2D TMDC-based mixed-dimensional heterostructures and their unique properties as visible-light-driven photocatalysts from the perspective of dimensionality and interface engineering.First,we discuss the approaches and advantages of surface modification and functionalization of 2D TMDCs for photocatalytic water splitting under visible-light illumination.We then classify the strategies for improving the photocatalytic activity of 2D TMDCs via combination with various low-dimensional nanomaterials to form mixed-dimensional heterostructures.Further,we highlight recent advances in the use of these mixed-dimensional heterostructures as high-efficiency visible-light-driven photocatalysts,particularly focusing on synthesis routes,modification approaches,and physiochemical mechanisms for improving their photoactivity.Finally,we provide our perspectives on future opportunities and challenges in promoting real-world photocatalytic applications of 2D TMDC-based heterostructures.展开更多
Hybrid perovskite solar cell(PSC)has attracted extensive research interest due to its rapid increase in efficiency,regarding as one of the most promising candidates for the next-generation photovoltaic technology.The ...Hybrid perovskite solar cell(PSC)has attracted extensive research interest due to its rapid increase in efficiency,regarding as one of the most promising candidates for the next-generation photovoltaic technology.The certified power conversion efficiency of the devices based on formamidinium lead iodide(FAPbI_(3))perovskite has reached 25.5%,approaching the record of monocrystalline silicon solar cells.Unfortunately,the blackα-phase FAPbI_(3)materials can spontaneously transform to non-optically activeδ-phase at room temperature,which greatly hinder their photovoltaic application.In order to overcome this problem,various strategies,especially introducing methylammonium(MA^(+)),caesium(Cs^(+))and bromide(Br^(-))ions into the materials,have been widely adopted.However,MA^(+)can largely reduce the thermal stability of the materials.Furthermore,the introduction of Br^(-)can enlarge the materials'bandgap,resulting in a reduced theoretical efficiency.Keeping these in mind,developing the strategies which without using MA^(+)and Br^(-)is the inevitable trend.Here,we focus on the recent progresses of stabilizingαFAPbI_(3)without employing MA^(+)and Br^(-),and discuss the advantages of inorganic ions doping and dimensionality engineering to stabilizedαFAPbI_(3).Meanwhile,in order to deeply understand the relationship between the semiconducting properties and device performance of the corresponding materials,we then summarize several significant strategies to suppress the non-radiation recombination,such as interface modification and trap passivation.Finally,we propose to develop more effective'A-site'alternatives to stabilizeαFAPbI_(3),which is expected to achieve high-efficient PSCs with long-term stability,facilitating its commercialization process.展开更多
The spatial resolution of X-ray imaging is often limited by radioluminescence scattering,which is exacerbated in thick scintillators and unpatterned films due to lateral light spreading.Commercial scintillators such a...The spatial resolution of X-ray imaging is often limited by radioluminescence scattering,which is exacerbated in thick scintillators and unpatterned films due to lateral light spreading.Commercial scintillators such as cesium iodide and gadolinium oxysulfide,although hundreds of micrometers thick to ensure efficient X-ray absorption,still suffer from optical crosstalk,complicated fabrication,and high production costs.To overcome these challenges,we report a novel micropatterned lead-free green and sustainable 1D Cu-based perovskite nanocrystals scintillator film.Specifically,polyethylene glycol-coated CsCu_(2)I_(3) nanocrystals are used to achieve improved quantum yield and precise thickness control,facilitated by the flexibility and compatibility of polyethylene glycol with the Cu-based nanocrystals.During polyethylene glycol treatment,zero-dimensional Cs_(3)Cu_(2)I_(5) nanocrystals transform into 1D CsCu_(2)I_(3) nanocrystals,occurring,accompanied by a pronounced redshift in emission,enabling the fabrication of yellow-emitting scintillator films.Further,photolithographic techniques are used to fabricate patterned substrates with varying pattern sizes and thicknesses,which were subsequently filled with polyethylene glycol-coated CsCu_(2)I_(3) nanocrystals via a hot-press method.The optimized micropatterned scintillator film effectively suppressed optical crosstalk and delivered enhanced spatial resolution under a clinically relevant tube voltage(80 kVp),outperforming unpatterned counterparts.X-ray imaging at such high voltage conditions has rarely been demonstrated using copper halide materials.This strategy highlights a practical route toward clinically relevant,scalable,and high-resolution scintillator films for advanced X-ray imaging.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:52303288,21878322,22075309,22378413Youth Innovation Promotion Association of Chinese Academy of Sciences and Biomaterials and Regenerative Medicine Institute Cooperative Research Project Shanghai Jiao Tong University School of Medicine,Grant/Award Number:2022LHA09。
文摘Covalent organic frameworks(COFs)have been developed as the precursors to construct porous carbons for electrocatalytic systems.However,the influences of carbon dimensions on the catalytic performance are still underexplored.In this work,we have first constructed COF-derived carbons by template-synthesis strategy in different dimensions to catalyze the carbon dioxide reduction(CO_(2)RR).By using different templates,the one-dimensional(1D),two-dimensional(2D),and three-dimensional(3D)COF-derived carbons have been employed to anchor Co-porphyrin to form the Co-N5 sites to catalyze CO_(2)RR.The 1D catalyst templated by carbon nano tubes presents high binding ability of CO_(2),more defective sites,and higher electronic conductivity,resulting in a higher catalytic activity for CO_(2)and selectivity of CO than 2D and 3D carbon-based catalysts.The 1D catalyst delivers the turnover frequency values of 1150 h^(−1)and the FECO of 94.5%at 0.7 V versus RHE,which is significantly better than those of 2D and 3D carbon-based catalysts.
文摘Geological strength index(GSI)has been widely used as an input parameter in predicting the strength and deformation properties of rock masses.This study derived a series of equations to satisfy the original GSI lines on the basic GSI chart.Two axes ranging from 0 to 100 were employed for surface conditions of the discontinuities and the structure of rock mass,which are independent of the input parameters.The derived equations can analyze GSI values ranging from 0 to 100 within±5%error.The engineering dimensions(EDs)such as the slope height,tunnel width,and foundation width were used together with representative elementary volume(REV)in jointed rock mass to define scale factor(sf)from 0.2 to 1 in evaluating the rock mass structure including joint pattern.The transformation of GSI into a scaledependent parameter based on engineering scale addresses a crucial requirement in various engineering applications.The improvements proposed in this study were applied to a real slope which was close to the time of failure.The results of stability assessments show that the new proposals have sufficient capability to define rock mass quality considering EDs.
基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDC0120103)Guangdong Basic and Applied Basic Research Foundation(2023B151520034)CAS Project for Young Scientists in Basic Research(YSBR-072)。
文摘Efficient and selective regeneration of enzymatically active 1,4-NADH from NAD^(+)is pivotal for accelerating photoenzymatic CO_(2)conversion.However,constructing photocatalysts that sustain continuous electron flow and provide sufficient hydride supply remains a major challenge.Herein,we report a rhodium-coordinated three-dimensional conjugated polymer(3D-Bpy-Rh)photocatalyst featuring multiple electron channels,designed through dimensionality engineering and incorporation of hydride-forming active centers.Such a 3D structure promotes rapid charge separation and multidimensional electron migration,while facilitating trapped-electron release to Rh centers for accelerated electron transfer.As a result,3D-Bpy-Rh achieves a visible-light driven NADH regeneration efficiency of 90.8%with 99.2%selectivity toward 1,4-NADH,surpassing state-of-the-art photocatalysts.Furthermore,the mechanism between the electron reduction capability of the photocatalyst and the selective formation of 1,4-NADH was elucidated,combining transient absorption spectroscopy analysis and DFT calculations.When integrated into photoenzymatic systems,this photocatalyst enhances CO_(2)conversion,boosting methanol and ethanol yields by 5.2-and 2.0-fold,respectively.These results highlighted the potential of dimensionality-engineered photocatalysts for selective 1,4-NADH regeneration and efficient photoenzymatic fuel synthesis.
基金the financial support from the Research Grants Council of Hong Kong(No.15304519)the National Natural Science Foundation of China(No.11904306)+2 种基金the Hong Kong Polytechnic University(No.1-ZVH9)The authors also thank the Fundamental Research Funds for the Central Universities(Nos.2019B02414 and 2019B44214)PAPD,and Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering,MOE(No.KLIEEE-18-02).
文摘Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical,electronic,and optical properties.This review focuses on the fundamentals of 2D TMDC-based mixed-dimensional heterostructures and their unique properties as visible-light-driven photocatalysts from the perspective of dimensionality and interface engineering.First,we discuss the approaches and advantages of surface modification and functionalization of 2D TMDCs for photocatalytic water splitting under visible-light illumination.We then classify the strategies for improving the photocatalytic activity of 2D TMDCs via combination with various low-dimensional nanomaterials to form mixed-dimensional heterostructures.Further,we highlight recent advances in the use of these mixed-dimensional heterostructures as high-efficiency visible-light-driven photocatalysts,particularly focusing on synthesis routes,modification approaches,and physiochemical mechanisms for improving their photoactivity.Finally,we provide our perspectives on future opportunities and challenges in promoting real-world photocatalytic applications of 2D TMDC-based heterostructures.
基金financial support from the National Natural Science Foundation of China(No.21771114,91956130)financial support from Distinguished Young Scholars of Tianjin(No.19JCJQJC62000)。
文摘Hybrid perovskite solar cell(PSC)has attracted extensive research interest due to its rapid increase in efficiency,regarding as one of the most promising candidates for the next-generation photovoltaic technology.The certified power conversion efficiency of the devices based on formamidinium lead iodide(FAPbI_(3))perovskite has reached 25.5%,approaching the record of monocrystalline silicon solar cells.Unfortunately,the blackα-phase FAPbI_(3)materials can spontaneously transform to non-optically activeδ-phase at room temperature,which greatly hinder their photovoltaic application.In order to overcome this problem,various strategies,especially introducing methylammonium(MA^(+)),caesium(Cs^(+))and bromide(Br^(-))ions into the materials,have been widely adopted.However,MA^(+)can largely reduce the thermal stability of the materials.Furthermore,the introduction of Br^(-)can enlarge the materials'bandgap,resulting in a reduced theoretical efficiency.Keeping these in mind,developing the strategies which without using MA^(+)and Br^(-)is the inevitable trend.Here,we focus on the recent progresses of stabilizingαFAPbI_(3)without employing MA^(+)and Br^(-),and discuss the advantages of inorganic ions doping and dimensionality engineering to stabilizedαFAPbI_(3).Meanwhile,in order to deeply understand the relationship between the semiconducting properties and device performance of the corresponding materials,we then summarize several significant strategies to suppress the non-radiation recombination,such as interface modification and trap passivation.Finally,we propose to develop more effective'A-site'alternatives to stabilizeαFAPbI_(3),which is expected to achieve high-efficient PSCs with long-term stability,facilitating its commercialization process.
基金supported by the National Research Foundation(NRF)of Korea(grant no:RS-2025-24683196).
文摘The spatial resolution of X-ray imaging is often limited by radioluminescence scattering,which is exacerbated in thick scintillators and unpatterned films due to lateral light spreading.Commercial scintillators such as cesium iodide and gadolinium oxysulfide,although hundreds of micrometers thick to ensure efficient X-ray absorption,still suffer from optical crosstalk,complicated fabrication,and high production costs.To overcome these challenges,we report a novel micropatterned lead-free green and sustainable 1D Cu-based perovskite nanocrystals scintillator film.Specifically,polyethylene glycol-coated CsCu_(2)I_(3) nanocrystals are used to achieve improved quantum yield and precise thickness control,facilitated by the flexibility and compatibility of polyethylene glycol with the Cu-based nanocrystals.During polyethylene glycol treatment,zero-dimensional Cs_(3)Cu_(2)I_(5) nanocrystals transform into 1D CsCu_(2)I_(3) nanocrystals,occurring,accompanied by a pronounced redshift in emission,enabling the fabrication of yellow-emitting scintillator films.Further,photolithographic techniques are used to fabricate patterned substrates with varying pattern sizes and thicknesses,which were subsequently filled with polyethylene glycol-coated CsCu_(2)I_(3) nanocrystals via a hot-press method.The optimized micropatterned scintillator film effectively suppressed optical crosstalk and delivered enhanced spatial resolution under a clinically relevant tube voltage(80 kVp),outperforming unpatterned counterparts.X-ray imaging at such high voltage conditions has rarely been demonstrated using copper halide materials.This strategy highlights a practical route toward clinically relevant,scalable,and high-resolution scintillator films for advanced X-ray imaging.
