Soft matter has attracted extensive attention due to its special physical/chemical properties and holds great promise in many applications. However, obtaining a detailed understanding of both complex fluid and mass tr...Soft matter has attracted extensive attention due to its special physical/chemical properties and holds great promise in many applications. However, obtaining a detailed understanding of both complex fluid and mass transport in soft matter, especially in hierarchical porous media of biological tissues, still remains a huge challenge. Herein, inspired by fast tracer transport in loose connective tissues of living systems, we observed an interesting phenomenon of fast molecular transport in situ in an artificial hierarchical multiphase porous medium （a micrometer scale hydrophobic fiber network filled with nanometer scale hydrophilic porous medium）, which was simply fabricated through electro- spinning technology and polymerization. The transportation speed of molecules in the micrometer fiber network is larger than simple diffusion in nanometer media, which is better described by Fick＇s law. We further proved that the phenomenon is based on the nanoconfined air/water/solid interface around the micrometer hydrophobic fibers. We focus on the key factors, referring to SA, （the confined multiphase area around the microfibers） and Nc （the connectivity node degree of the skeletal portion in the nanometer hydrogel medium）. Next, a quantitative parameter, VTCM （transport chance mean-value）, was introduced to describe the molecular transport capability of the fiber network within hierarchical multiphase porous systems. These fundamental advances can be applied de novo to understand the process of so-called simple diffusion in biological systems, and even to re-describe many molecular events in biologically nanoconfined spaces.展开更多
Hierarchical Co3O4 porous nanowires （NWs） have been synthesized using a hydrothermal method followed by calcination. When employed as a cathode catalyst in non-aqueous Li-oxygen batteries, the Co3O4 NWs effectively ...Hierarchical Co3O4 porous nanowires （NWs） have been synthesized using a hydrothermal method followed by calcination. When employed as a cathode catalyst in non-aqueous Li-oxygen batteries, the Co3O4 NWs effectively improve both the round-trip efficiency and cycling stability, which can be attributed to the high catalytic activities of Co3O4 NWs for the oxygen reduction reaction and the oxygen evolution reaction during discharge and charge processes, respectively.展开更多
Graphene is a one-atom-thick sheet of graphite comprising sp2-hybridized carbon atoms arranged in the hexagonal honeycomb lattices. By removing the honeycomb lattices and forming nanopores with specific geometry and s...Graphene is a one-atom-thick sheet of graphite comprising sp2-hybridized carbon atoms arranged in the hexagonal honeycomb lattices. By removing the honeycomb lattices and forming nanopores with specific geometry and size, nanoporous graphene has been demonstrated as a very high-efficiency separation membrane, due to the ultrafast molecular permeation rate for its one-atom thickness. This review focuses on the recent advances in nanoporous graphene membrane for the applications of gas separation and water purification, with a major emphasis on the molecular permeation mechanisms and the advanced fabrication methods of this state-of-the-art membrane. We highlight the advanced theoretical and experimental works and discuss the gas/water molecular transport mechanisms through the graphene nanopores accompanied with theoretical models. In addition, we summarize some representative membrane fabrication methods, covering the graphene transfer to porous substrates and the pore generation. We anticipate that this review can provide a platform for understanding the current challenges to make the conceptual membrane a reality and attracting more and more attentions from scientists and engineers.展开更多
自从1991年M．Grhtzel教授将纳米多孔的概念引入染料敏化宽禁带TiO2半导体研究中，获得光电转换效率7．1％的染料敏化太阳电池（Dyesensitized Solar Cell，以下略作DSC）以来，DSC以其潜在的低成本、相对简单的制作工艺和技术等优势赢...自从1991年M．Grhtzel教授将纳米多孔的概念引入染料敏化宽禁带TiO2半导体研究中，获得光电转换效率7．1％的染料敏化太阳电池（Dyesensitized Solar Cell，以下略作DSC）以来，DSC以其潜在的低成本、相对简单的制作工艺和技术等优势赢得了人们的广泛重视。展开更多
To improve the contact between platinum catalyst and titanium substrate, a layer of TiO2 nanotube arrays has been synthesized before depositing Pt nanoflowers by pulse electrodeposition. Dramatic improvements in elect...To improve the contact between platinum catalyst and titanium substrate, a layer of TiO2 nanotube arrays has been synthesized before depositing Pt nanoflowers by pulse electrodeposition. Dramatic improvements in electrocatalytic activity （3x） and stability （60x） for methanol oxidation were found, suggesting promising applications in direct methanol fuel cells. The 3x and 60x improvements persist for Pt/Pd catalysts used to overcome the CO poisoning problem.展开更多
基金This study was supported by the National Natural Science Foundation of China （No. 81141118） and the National Basic Research Program of China （973 Program） （Nos. 2012CB9333800 and 2012CB518506）.
文摘Soft matter has attracted extensive attention due to its special physical/chemical properties and holds great promise in many applications. However, obtaining a detailed understanding of both complex fluid and mass transport in soft matter, especially in hierarchical porous media of biological tissues, still remains a huge challenge. Herein, inspired by fast tracer transport in loose connective tissues of living systems, we observed an interesting phenomenon of fast molecular transport in situ in an artificial hierarchical multiphase porous medium （a micrometer scale hydrophobic fiber network filled with nanometer scale hydrophilic porous medium）, which was simply fabricated through electro- spinning technology and polymerization. The transportation speed of molecules in the micrometer fiber network is larger than simple diffusion in nanometer media, which is better described by Fick＇s law. We further proved that the phenomenon is based on the nanoconfined air/water/solid interface around the micrometer hydrophobic fibers. We focus on the key factors, referring to SA, （the confined multiphase area around the microfibers） and Nc （the connectivity node degree of the skeletal portion in the nanometer hydrogel medium）. Next, a quantitative parameter, VTCM （transport chance mean-value）, was introduced to describe the molecular transport capability of the fiber network within hierarchical multiphase porous systems. These fundamental advances can be applied de novo to understand the process of so-called simple diffusion in biological systems, and even to re-describe many molecular events in biologically nanoconfined spaces.
文摘Hierarchical Co3O4 porous nanowires （NWs） have been synthesized using a hydrothermal method followed by calcination. When employed as a cathode catalyst in non-aqueous Li-oxygen batteries, the Co3O4 NWs effectively improve both the round-trip efficiency and cycling stability, which can be attributed to the high catalytic activities of Co3O4 NWs for the oxygen reduction reaction and the oxygen evolution reaction during discharge and charge processes, respectively.
基金supported by the National Natural Science Foundation of China(51425603 and 51236007)
文摘Graphene is a one-atom-thick sheet of graphite comprising sp2-hybridized carbon atoms arranged in the hexagonal honeycomb lattices. By removing the honeycomb lattices and forming nanopores with specific geometry and size, nanoporous graphene has been demonstrated as a very high-efficiency separation membrane, due to the ultrafast molecular permeation rate for its one-atom thickness. This review focuses on the recent advances in nanoporous graphene membrane for the applications of gas separation and water purification, with a major emphasis on the molecular permeation mechanisms and the advanced fabrication methods of this state-of-the-art membrane. We highlight the advanced theoretical and experimental works and discuss the gas/water molecular transport mechanisms through the graphene nanopores accompanied with theoretical models. In addition, we summarize some representative membrane fabrication methods, covering the graphene transfer to porous substrates and the pore generation. We anticipate that this review can provide a platform for understanding the current challenges to make the conceptual membrane a reality and attracting more and more attentions from scientists and engineers.
文摘To improve the contact between platinum catalyst and titanium substrate, a layer of TiO2 nanotube arrays has been synthesized before depositing Pt nanoflowers by pulse electrodeposition. Dramatic improvements in electrocatalytic activity （3x） and stability （60x） for methanol oxidation were found, suggesting promising applications in direct methanol fuel cells. The 3x and 60x improvements persist for Pt/Pd catalysts used to overcome the CO poisoning problem.
