Surface hybrid inorganic semiconductors photocatalysts withπconjugated structure have recently been widely used in the field of photocatalytic environmental remediation and energy conversion.Surface hybridization is ...Surface hybrid inorganic semiconductors photocatalysts withπconjugated structure have recently been widely used in the field of photocatalytic environmental remediation and energy conversion.Surface hybridization is considered to be an efficient way to significantly enhance the photocatalytic activity by several times,completely inhibit photocorrosion of inorganic photocatalysts and expand the spectral response range of photocatalysts.This review provides a comprehensive overview of the surface hybridization definition,the principle of enhancing photocatalytic performance and the control factors of surface hybridization to promote photoactivity.Summarize the preparation and structural identification method of the surface hybrid photocatalyst.Special emphasis is placed on the various photocatalytic system construction of surface hybridization.The development of surface hybrid photocatalysts for pollutant degradation and energy conversion are further presented.Finally,the challenges and future development prospects of surface hybridization in photocatalysis are discussed.We hope this critical review can provide a clear picture of the state-of-the-art achievements and facilitate the applications of surface hybrid photocatalysts in environmental remediation and energy conversion.展开更多
A novel nanolaser structure based on a hybrid plasmonic waveguide is proposed and investigated. The coupling between the metal nanowire and the high-index semiconductor nanowire with optical gain leads to a strong fie...A novel nanolaser structure based on a hybrid plasmonic waveguide is proposed and investigated. The coupling between the metal nanowire and the high-index semiconductor nanowire with optical gain leads to a strong field enhancement in the air gap region and low propagation loss, which enables the realization of lasing at the deep subwavelength scale.By optimizing the geometric parameters of the structure, a minimal lasing threshold is achieved while maintaining the capacity of ultra-deep subwavelength mode confinement. Compared with the previous coupled nanowire pair based hybrid plasmonic structure, a lower threshold can be obtained with the same geometric parameters. The proposed nanolaser can be integrated into a miniature chip as a nanoscale light source and has the potential to be widely used in optical communication and optical sensing technology.展开更多
The propagation length of surface plasmon polaritons(SPPs) is intrinsically limited by the metallic ohmic loss that is enhanced by the strongly confined electromagnetic field. In this paper, we propose a new class o...The propagation length of surface plasmon polaritons(SPPs) is intrinsically limited by the metallic ohmic loss that is enhanced by the strongly confined electromagnetic field. In this paper, we propose a new class of hybrid plasmonic waveguides(HPWs) that can support long-range SPP propagation while keeping subwavelength optical field confinement. It is shown that the coupling between the waveguides can be well tuned by simply varying the structural parameters. Compared with conventional HPWs, a larger propagation length as well as a better optical field confinement can be simultaneously realized. The proposed structure with better optical performance can be useful for future photonic device design and optical integration research.展开更多
The major concern of this work is to propose new prototypes of surface hybrid waves, in particular waves propagating without sprawl or deformation on the surface of a fluid. The model considered for this purpose is th...The major concern of this work is to propose new prototypes of surface hybrid waves, in particular waves propagating without sprawl or deformation on the surface of a fluid. The model considered for this purpose is the modified KdV (Korteweg-de Vries) equation. A peculiarity of the obtained solutions is that they form packages constituted by combinations of waves belonging to the two main families of well-known bright and dark solitary waves. This putting together creates competitions between the different components of the considered packages which, following the values assigned to the parameters of the considered system and in relation to those of the wave parameters, generate hybrid or multi-form structures. The direct method of resolution which made possible the obtained results is that of Bogning-Djeumen Tchaho-Kofane extended to the new implicit Bogning functions. The existence conditions of some solutions are obtained. The numerical simulations carried out with a view to testing the observable and applicable characters of the obtained solutions revealed their stabilities over a relatively long time, and at the same time, confirmed the recommended theoretical forecasts. We are convinced that the solutions proposed as part of this work will make it possible to detect, understand and explain some physical phenomena linked to fluid molecular interactions, former or new, which constantly occur on the fluid surfaces, mainly at the shallow water surface.展开更多
With appropriate stimuli,such as heat,humidity,or magnetic field,shape memory polymers(SMPs)can recover to their original shapes from temporary,programmed states.Using thermal responsive SMPs as substrates,we demonstr...With appropriate stimuli,such as heat,humidity,or magnetic field,shape memory polymers(SMPs)can recover to their original shapes from temporary,programmed states.Using thermal responsive SMPs as substrates,we demonstrate a simple method to realize hybrid surface morphologies through confined thin film wrinkling in localized areas.The bilayer system was fabricated by depositing a layer of aluminum thin?lm on top of a SMP substrate programmed with a tensile strain.After the system was heated by a heating wire,hybrid wrinkling patterns were formed in a confined circular area around the heat source,with an inner spoke pattern and an outer ring pattern.Wrinkling patterns showed good symmetry,and the size of the wrinkling area can be tuned by controlling the heat input.This study o?ers a simple but effective approach to fabricate hybrid morphological features in micro-scale.With appropriate stimuli,such as heat,humidity,or magnetic field,shape memory polymers(SMPs)can recover to their original shapes from temporary,programmed states.Using thermal responsive SMPs as substrates,we demonstrate a simple method to realize hybrid surface morphologies through confined thin film wrinkling in localized areas.The bilayer system was fabricated by depositing a layer of aluminum thin?lm on top of a SMP substrate programmed with a tensile strain.After the system was heated by a heating wire,hybrid wrinkling patterns were formed in a confined circular area around the heat source,with an inner spoke pattern and an outer ring pattern.Wrinkling patterns showed good symmetry,and the size of the wrinkling area can be tuned by controlling the heat input.This study offers a simple but effective approach to fabricate hybrid morphological features in micro-scale.展开更多
A model is proposed to predict and evaluate the heat transfer characteristics of dropwise-filmwise hybrid surface.This is approached by modifying the original drop-size distribution,which is defined for fully dropwise...A model is proposed to predict and evaluate the heat transfer characteristics of dropwise-filmwise hybrid surface.This is approached by modifying the original drop-size distribution,which is defined for fully dropwise condensation(DWC)and making it applicable for dropwise-filmwise condensation(DFC).The modification is achieved by simulation work to determine two parameters:the area fraction occupied by large drops f and the ratio of the maximum radius of newly formed drops to that of larger drops γ.Simulation results show a good agreement with the literature for fully DWC and provide a correlation for each parameter with respect to DWC region width in the DFC hybrid surface.The present model evaluates the heat transfer performance of DFC by utilizing these correlations.A comparison is made between the proposed model with experimental work from the literature and results show a good agreement.While changing filmwise condensation(FWC)region width significantly affects the overall heat transfer performance,utilizing smaller width to that of DWC region has the advantage over fully DWC.Furthermore,surface renewal within the hydrophobic region is controlled by adjusting the DWC region width.When the ratio of drop maximum diameter to DWC region width is unity,surface renewal is achieved by drops merging to adjacent FWC regions only.When the ratio is less than unity,surface renewal is achieved by sweeping of departing drops within the hydrophobic region and by merging.For each case,an optimum DWC region width which corresponds to the maximum DFC heat flux is defined.展开更多
To address the capacity degradation,voltage fading,structural instability and adverse interface reactions in cathode materi-als of lithium-ion batteries(LIBs),numerous modification strategies have been developed,mainl...To address the capacity degradation,voltage fading,structural instability and adverse interface reactions in cathode materi-als of lithium-ion batteries(LIBs),numerous modification strategies have been developed,mainly including coating and doping.In particular,the important strategy of doping(surface doping and bulk doping)has been considered an effective strategy to modulate the crystal lattice structure of cathode materials.However,special insights into the mechanisms and effectiveness of the doping strategy,especially comparisons between surface doping and bulk doping in cathode materials,are still lacking.In this review,recent significant progress in surface doping and bulk doping strategies is demonstrated in detail by focusing on their inherent differences as well as effects on the structural stability,lithium-ion(Li-ion)diffusion and electrochemical properties of cathode materials from the following mechanistic insights:preventing the exposure of reactive Ni on the surface,stabilizing the Li slabs,mitigating the migration of transition metal(TM)ions,alleviating unde-sired structural transformations and adverse interface issues,enlarging the Li interslab spacing,forming three-dimensional(3D)Li-ion diffusion channels,and providing more active sites for the charge-transfer process.Moreover,insights into the correlation between the mechanisms of hybrid surface engineering strategies(doping and coating)and their influences on the electrochemical performance of cathode materials are provided by emphasizing the stabilization of the Li slabs,the enhancement of the surface chemical stability,and the alleviation of TM ion migration.Furthermore,the existing challenges and future perspectives in this promising field are indicated.展开更多
A TiO2 heterostructure modified with carbon nitride nanosheets (CN-NSs) has been synthesized via a direct interfacial assembly strategy. The CN-NSs, which have a unique two-dimensional structure, were favorable for ...A TiO2 heterostructure modified with carbon nitride nanosheets (CN-NSs) has been synthesized via a direct interfacial assembly strategy. The CN-NSs, which have a unique two-dimensional structure, were favorable for supporting TiOa nanoparticles (NPs). The uniform dispersion of TiO2 NPs on the surface of the CN-NSs creates sufficient interfacial contact at their nanojunctions, as was confirmed by electron microscopy analyses. In comparison with other reported metal oxide/CN composites, the strong interactions of the ultrathin CN-NSs layers with the TiO2 nanoparticles restrain their re-stacking, which results in a large specific surface area of 234.0 m2.g-1. The results indicate that the optimized TiOJCN-NSs hybrid exhibits remarkably enhanced photocatalytic efficiency for dye degradation (with k of 0.167 min-1 under full spectrum) and Ha production (with apparent quantum yield -- 38.4% for A = 400 + 15 nm monochromatic light). This can be ascribed to the improved surface area and quantum efficiency of the hybrid, with a controlled ratio that reaches the appropriate balance between producing sufficient nanojunctions and absorbing enough photons. Furthermore, based on the identification of the main active species for photodegradation, and the confirmation of active sites for H2 evolution, the charge transfer pathway across the TiO2/CN-NSs interface under simulated solar light is proposed.展开更多
基金This study was partly supported by the National Natural Science Foundation of China(No.21872077,21673126,21761142017,21621003)Collaborative Innovation Centre for Regional Environmental Quality。
文摘Surface hybrid inorganic semiconductors photocatalysts withπconjugated structure have recently been widely used in the field of photocatalytic environmental remediation and energy conversion.Surface hybridization is considered to be an efficient way to significantly enhance the photocatalytic activity by several times,completely inhibit photocorrosion of inorganic photocatalysts and expand the spectral response range of photocatalysts.This review provides a comprehensive overview of the surface hybridization definition,the principle of enhancing photocatalytic performance and the control factors of surface hybridization to promote photoactivity.Summarize the preparation and structural identification method of the surface hybrid photocatalyst.Special emphasis is placed on the various photocatalytic system construction of surface hybridization.The development of surface hybrid photocatalysts for pollutant degradation and energy conversion are further presented.Finally,the challenges and future development prospects of surface hybridization in photocatalysis are discussed.We hope this critical review can provide a clear picture of the state-of-the-art achievements and facilitate the applications of surface hybrid photocatalysts in environmental remediation and energy conversion.
基金Project supported by the National Natural Science Foundation of China(Grant No.61172044)the Natural Science Foundation of Hebei Province,China(Grant No.F2014501150)
文摘A novel nanolaser structure based on a hybrid plasmonic waveguide is proposed and investigated. The coupling between the metal nanowire and the high-index semiconductor nanowire with optical gain leads to a strong field enhancement in the air gap region and low propagation loss, which enables the realization of lasing at the deep subwavelength scale.By optimizing the geometric parameters of the structure, a minimal lasing threshold is achieved while maintaining the capacity of ultra-deep subwavelength mode confinement. Compared with the previous coupled nanowire pair based hybrid plasmonic structure, a lower threshold can be obtained with the same geometric parameters. The proposed nanolaser can be integrated into a miniature chip as a nanoscale light source and has the potential to be widely used in optical communication and optical sensing technology.
基金Project supported by the National Natural Science Foundation of China(Grant No.11647021)the Fundamental Research Funds for the Central Universities of China(Grant No.ZY1531)
文摘The propagation length of surface plasmon polaritons(SPPs) is intrinsically limited by the metallic ohmic loss that is enhanced by the strongly confined electromagnetic field. In this paper, we propose a new class of hybrid plasmonic waveguides(HPWs) that can support long-range SPP propagation while keeping subwavelength optical field confinement. It is shown that the coupling between the waveguides can be well tuned by simply varying the structural parameters. Compared with conventional HPWs, a larger propagation length as well as a better optical field confinement can be simultaneously realized. The proposed structure with better optical performance can be useful for future photonic device design and optical integration research.
文摘The major concern of this work is to propose new prototypes of surface hybrid waves, in particular waves propagating without sprawl or deformation on the surface of a fluid. The model considered for this purpose is the modified KdV (Korteweg-de Vries) equation. A peculiarity of the obtained solutions is that they form packages constituted by combinations of waves belonging to the two main families of well-known bright and dark solitary waves. This putting together creates competitions between the different components of the considered packages which, following the values assigned to the parameters of the considered system and in relation to those of the wave parameters, generate hybrid or multi-form structures. The direct method of resolution which made possible the obtained results is that of Bogning-Djeumen Tchaho-Kofane extended to the new implicit Bogning functions. The existence conditions of some solutions are obtained. The numerical simulations carried out with a view to testing the observable and applicable characters of the obtained solutions revealed their stabilities over a relatively long time, and at the same time, confirmed the recommended theoretical forecasts. We are convinced that the solutions proposed as part of this work will make it possible to detect, understand and explain some physical phenomena linked to fluid molecular interactions, former or new, which constantly occur on the fluid surfaces, mainly at the shallow water surface.
基金The financial supports from NSF(CMMI-1405355)and ACS Petroleum Research Fund(53780-DNI7)are gratefully acknowledged.
文摘With appropriate stimuli,such as heat,humidity,or magnetic field,shape memory polymers(SMPs)can recover to their original shapes from temporary,programmed states.Using thermal responsive SMPs as substrates,we demonstrate a simple method to realize hybrid surface morphologies through confined thin film wrinkling in localized areas.The bilayer system was fabricated by depositing a layer of aluminum thin?lm on top of a SMP substrate programmed with a tensile strain.After the system was heated by a heating wire,hybrid wrinkling patterns were formed in a confined circular area around the heat source,with an inner spoke pattern and an outer ring pattern.Wrinkling patterns showed good symmetry,and the size of the wrinkling area can be tuned by controlling the heat input.This study o?ers a simple but effective approach to fabricate hybrid morphological features in micro-scale.With appropriate stimuli,such as heat,humidity,or magnetic field,shape memory polymers(SMPs)can recover to their original shapes from temporary,programmed states.Using thermal responsive SMPs as substrates,we demonstrate a simple method to realize hybrid surface morphologies through confined thin film wrinkling in localized areas.The bilayer system was fabricated by depositing a layer of aluminum thin?lm on top of a SMP substrate programmed with a tensile strain.After the system was heated by a heating wire,hybrid wrinkling patterns were formed in a confined circular area around the heat source,with an inner spoke pattern and an outer ring pattern.Wrinkling patterns showed good symmetry,and the size of the wrinkling area can be tuned by controlling the heat input.This study offers a simple but effective approach to fabricate hybrid morphological features in micro-scale.
文摘A model is proposed to predict and evaluate the heat transfer characteristics of dropwise-filmwise hybrid surface.This is approached by modifying the original drop-size distribution,which is defined for fully dropwise condensation(DWC)and making it applicable for dropwise-filmwise condensation(DFC).The modification is achieved by simulation work to determine two parameters:the area fraction occupied by large drops f and the ratio of the maximum radius of newly formed drops to that of larger drops γ.Simulation results show a good agreement with the literature for fully DWC and provide a correlation for each parameter with respect to DWC region width in the DFC hybrid surface.The present model evaluates the heat transfer performance of DFC by utilizing these correlations.A comparison is made between the proposed model with experimental work from the literature and results show a good agreement.While changing filmwise condensation(FWC)region width significantly affects the overall heat transfer performance,utilizing smaller width to that of DWC region has the advantage over fully DWC.Furthermore,surface renewal within the hydrophobic region is controlled by adjusting the DWC region width.When the ratio of drop maximum diameter to DWC region width is unity,surface renewal is achieved by drops merging to adjacent FWC regions only.When the ratio is less than unity,surface renewal is achieved by sweeping of departing drops within the hydrophobic region and by merging.For each case,an optimum DWC region width which corresponds to the maximum DFC heat flux is defined.
基金the National Natural Science Foundation of China(52072298 and 51802261)the Local Special Service Program Funded by Education Department of Shaanxi Provincial Government(19JC031)+2 种基金the Natural Science Foundation of Shaanxi(2020JC-41,2021TD-15)the Xi’an Science and Technology Project of China(2019219714SYS012CG034)the Project 2019JLP-04 supported by the Joint Foundation of Shaanxi.
文摘To address the capacity degradation,voltage fading,structural instability and adverse interface reactions in cathode materi-als of lithium-ion batteries(LIBs),numerous modification strategies have been developed,mainly including coating and doping.In particular,the important strategy of doping(surface doping and bulk doping)has been considered an effective strategy to modulate the crystal lattice structure of cathode materials.However,special insights into the mechanisms and effectiveness of the doping strategy,especially comparisons between surface doping and bulk doping in cathode materials,are still lacking.In this review,recent significant progress in surface doping and bulk doping strategies is demonstrated in detail by focusing on their inherent differences as well as effects on the structural stability,lithium-ion(Li-ion)diffusion and electrochemical properties of cathode materials from the following mechanistic insights:preventing the exposure of reactive Ni on the surface,stabilizing the Li slabs,mitigating the migration of transition metal(TM)ions,alleviating unde-sired structural transformations and adverse interface issues,enlarging the Li interslab spacing,forming three-dimensional(3D)Li-ion diffusion channels,and providing more active sites for the charge-transfer process.Moreover,insights into the correlation between the mechanisms of hybrid surface engineering strategies(doping and coating)and their influences on the electrochemical performance of cathode materials are provided by emphasizing the stabilization of the Li slabs,the enhancement of the surface chemical stability,and the alleviation of TM ion migration.Furthermore,the existing challenges and future perspectives in this promising field are indicated.
基金We thank the Analysis and Testing Center, Huazhong University of Science and Technology for their assistance in characterization of materials. This work is supported by the National Natural Science Foundation of China (No. 21571071), Hubei Provincial Natural Science Foundation of China (No. 2015CFB313), and the Fundamental Research Funds for the Central Universities (No. 2015QN183).
文摘A TiO2 heterostructure modified with carbon nitride nanosheets (CN-NSs) has been synthesized via a direct interfacial assembly strategy. The CN-NSs, which have a unique two-dimensional structure, were favorable for supporting TiOa nanoparticles (NPs). The uniform dispersion of TiO2 NPs on the surface of the CN-NSs creates sufficient interfacial contact at their nanojunctions, as was confirmed by electron microscopy analyses. In comparison with other reported metal oxide/CN composites, the strong interactions of the ultrathin CN-NSs layers with the TiO2 nanoparticles restrain their re-stacking, which results in a large specific surface area of 234.0 m2.g-1. The results indicate that the optimized TiOJCN-NSs hybrid exhibits remarkably enhanced photocatalytic efficiency for dye degradation (with k of 0.167 min-1 under full spectrum) and Ha production (with apparent quantum yield -- 38.4% for A = 400 + 15 nm monochromatic light). This can be ascribed to the improved surface area and quantum efficiency of the hybrid, with a controlled ratio that reaches the appropriate balance between producing sufficient nanojunctions and absorbing enough photons. Furthermore, based on the identification of the main active species for photodegradation, and the confirmation of active sites for H2 evolution, the charge transfer pathway across the TiO2/CN-NSs interface under simulated solar light is proposed.