We reported the synthesis of nitrogen-doped carbon using surface-attached polyelectrolyte layers as precursors. The synthesized material has a large surface area of 800 m^2·g^-1 with uniformed pore distribution. ...We reported the synthesis of nitrogen-doped carbon using surface-attached polyelectrolyte layers as precursors. The synthesized material has a large surface area of 800 m^2·g^-1 with uniformed pore distribution. Benefitfed from the high pyridinic nitrogen content, the synthesized nitrogen-doped porous carbon material exhibits promising electrocatalytic activity toward oxygen reduction reactions in acidic medium and very high stability against continuous cyclic voltammetry scans. The experimental results demonstrate that surface-attached polyelectrolyte layers are promising carbon and nitrogen sources for the formation of heteroatom-doped porous carbon materials.展开更多
Adsorption of poly（L-lysine） on surface-attached poly（methacrylic acid） monolayers formed through in situ free radical polymerization was investigated. A strong ＂template effect＂ was observed for the adsorption ...Adsorption of poly（L-lysine） on surface-attached poly（methacrylic acid） monolayers formed through in situ free radical polymerization was investigated. A strong ＂template effect＂ was observed for the adsorption of poly（L-lysine） on poly（methacrylic acid） layers, which were perpendicularly grown from the surface of substrates. The adsorbed amount of poly（amino acid） increases linearly with the increase in initial layer thickness of poly（methacrylic acid） monolayers. In addition, the adsorbed poly（amino acid） is relatively stable in medium concentration of salt solution but can be completely released from the brush in high salt concentration.展开更多
Hollow nitrogen-doped porous carbon materials covered with different thicknesses of carbon layers were synthesized to assist evaluation of the influence of nitrogen atom on the surrounding carbon atoms.The designed ca...Hollow nitrogen-doped porous carbon materials covered with different thicknesses of carbon layers were synthesized to assist evaluation of the influence of nitrogen atom on the surrounding carbon atoms.The designed carbon-based materials were synthesized through pyrolysis of surface-attached block copolymer layers on silica nanoparticles with different thicknesses of the second block of grafted polymer chains,followed by removal of silica templates.The experimental results reveal that coverage a carbon layer with proper thickness can improve the oxygen reaction reduction activity of nitrogen-doped carbon materials as evidenced by the positive shift of half-wave potential in linear scanning voltammetry response curves.The conclusions may provide a reference work on understanding the active sites and designing materials with superior electrochemical performance.展开更多
Amine-functionalized imidazolium-based poly(ionic liquid)brushes on mesoporous silica were synthesized via"grafting through"technique and were applied as model sorbents to understand physisorption and chemis...Amine-functionalized imidazolium-based poly(ionic liquid)brushes on mesoporous silica were synthesized via"grafting through"technique and were applied as model sorbents to understand physisorption and chemisorption of carbon dioxide molecules.The experimental results reveal that the total adsorption capacity of model sorbents derived from temperature programmed desorption(TPD)approach reaches 1.72 mmol·g^-1 that is much higher than the sum of adsorption capacity of bare mesoporous silica and free polymers at 25℃under carbon dioxide partial pressure of 0.2 bar.The proposed physical adsorption and chemical adsorption of carbon dioxide molecules in TPD response curves were validated by volumetric desorption measurement.It is also observed that physical adsorption is completely reversible and chemical adsorption is irreversible.The results demonstrate that the temperature programmed desorption technique is an effective approach to differentiate chemisorption and physisorption of gaseous species on solid sorbents,which is beneficial for understanding of adsorption mechanism and materials design.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.21576216 and 51372192)
文摘We reported the synthesis of nitrogen-doped carbon using surface-attached polyelectrolyte layers as precursors. The synthesized material has a large surface area of 800 m^2·g^-1 with uniformed pore distribution. Benefitfed from the high pyridinic nitrogen content, the synthesized nitrogen-doped porous carbon material exhibits promising electrocatalytic activity toward oxygen reduction reactions in acidic medium and very high stability against continuous cyclic voltammetry scans. The experimental results demonstrate that surface-attached polyelectrolyte layers are promising carbon and nitrogen sources for the formation of heteroatom-doped porous carbon materials.
基金Funded by the National Natural Science Foundation of China(21576216)
文摘Adsorption of poly（L-lysine） on surface-attached poly（methacrylic acid） monolayers formed through in situ free radical polymerization was investigated. A strong ＂template effect＂ was observed for the adsorption of poly（L-lysine） on poly（methacrylic acid） layers, which were perpendicularly grown from the surface of substrates. The adsorbed amount of poly（amino acid） increases linearly with the increase in initial layer thickness of poly（methacrylic acid） monolayers. In addition, the adsorbed poly（amino acid） is relatively stable in medium concentration of salt solution but can be completely released from the brush in high salt concentration.
基金Funded by the Guangdong Key R&D Program(2020B0909040001)the Opening Project of State Key Laboratory of Advanced Technology for Float Glass(2018KF03)。
文摘Hollow nitrogen-doped porous carbon materials covered with different thicknesses of carbon layers were synthesized to assist evaluation of the influence of nitrogen atom on the surrounding carbon atoms.The designed carbon-based materials were synthesized through pyrolysis of surface-attached block copolymer layers on silica nanoparticles with different thicknesses of the second block of grafted polymer chains,followed by removal of silica templates.The experimental results reveal that coverage a carbon layer with proper thickness can improve the oxygen reaction reduction activity of nitrogen-doped carbon materials as evidenced by the positive shift of half-wave potential in linear scanning voltammetry response curves.The conclusions may provide a reference work on understanding the active sites and designing materials with superior electrochemical performance.
基金Funded by the National Natural Science Foundation of China(No.21878239)。
文摘Amine-functionalized imidazolium-based poly(ionic liquid)brushes on mesoporous silica were synthesized via"grafting through"technique and were applied as model sorbents to understand physisorption and chemisorption of carbon dioxide molecules.The experimental results reveal that the total adsorption capacity of model sorbents derived from temperature programmed desorption(TPD)approach reaches 1.72 mmol·g^-1 that is much higher than the sum of adsorption capacity of bare mesoporous silica and free polymers at 25℃under carbon dioxide partial pressure of 0.2 bar.The proposed physical adsorption and chemical adsorption of carbon dioxide molecules in TPD response curves were validated by volumetric desorption measurement.It is also observed that physical adsorption is completely reversible and chemical adsorption is irreversible.The results demonstrate that the temperature programmed desorption technique is an effective approach to differentiate chemisorption and physisorption of gaseous species on solid sorbents,which is beneficial for understanding of adsorption mechanism and materials design.
