应用扫描电镜(SEM)、X射线光电子能谱(XPS)和衰减全反射红外光谱(FTIR-ATR)等现代表面分析技术研究不同改性处理羊毛表面的化学和物理结构特性.SEM研究结果表明,经低温等离子体表面改性或特定化学改性后的羊毛鳞片表面呈现纳米尺度的沟...应用扫描电镜(SEM)、X射线光电子能谱(XPS)和衰减全反射红外光谱(FTIR-ATR)等现代表面分析技术研究不同改性处理羊毛表面的化学和物理结构特性.SEM研究结果表明,经低温等离子体表面改性或特定化学改性后的羊毛鳞片表面呈现纳米尺度的沟槽和凹凸结构,应用Wenzel公式和Cassie and Baxter公式阐述了表面粗糙度与接触角的关系,揭示了羊毛表面改性对于提高拒水拒油整理效果的原因所在.XPS和FTIR-ATR研究表明,上述物理和化学的表面改性技术使羊毛表面的二硫键氧化断裂和表面类脂物质改性/除去,促进拒水拒油整理剂的吸附和固着.表面改性和拒水拒油整理的协同效应赋予羊毛类荷叶效应,使其呈现超级拒水拒油拒污功能.展开更多
Photocatalytic conversion efficiency is limited by serious charge carrier recombination. Efficient carrier separation is usually achieved by elegantly-designed multi-component structures connected by directional elect...Photocatalytic conversion efficiency is limited by serious charge carrier recombination. Efficient carrier separation is usually achieved by elegantly-designed multi-component structures connected by directional electric field. Herein, we developed a twodimensional(2 D) sandwich structure, as a new photocatalytic system, to realize high-efficiency carrier separation. This strategy integrated multifunction into a single structure for the first time, which successfully introduces a stable built-in electric field,realizing high-effective carrier separation. Besides, the carrier concentration is dramatically increased due to dimensional confinement. Benefiting from above synergic advantages, 2 D sandwich photocatalyst achieves the highest nitrogen fixation rate(435 μmol g^(-1) h^(-1)) in inorganic solid photocatalysts under visible light irradiation. We anticipate that 2 D sandwich photocatalyst holds promises for the application and expansion of 2 D materials in photocatalysis research.展开更多
Tetradecyldimethylbenzyl ammonium salt（TDMBA） cations were intercalated into sodium montmorillonite（Na-MMT） by an ion exchange reaction. The resulting TDMBA-MMT was characterized by Fourier-transform infrared spec...Tetradecyldimethylbenzyl ammonium salt（TDMBA） cations were intercalated into sodium montmorillonite（Na-MMT） by an ion exchange reaction. The resulting TDMBA-MMT was characterized by Fourier-transform infrared spectroscopy（FTIR）, thermogravimetric analysis（TGA）, and X-ray diffraction（XRD）. Moreover, the antibacterial activity and water-resistance of TDMBA-MMT were investigated. The results show that TDMBA cations are intercalated into the Na-MMT. The onset temperature of decomposition of TDMBA cations in TDMBA-MMT is raised about 60 ℃ higher than that of tetradecyldimethylbenzyl ammonium chloride（TDMBACl）, and the d（001） spacing enlarged from 1.23 nm to 2.10 nm. 0.1 mg/mL TDMBA-MMT is fully enough to kill all the Staphylococci aureus（S, aureus） and more than 99.99% of the Escherichia coli（E, coli） in a sample solution within 6.0 h touch, and the TDMBA-MMT also shows long acting properties.展开更多
The work function （WF） of indium-tin-oxide （ITO） substrates plays an important role on the inverted organic photovoltaic device performance. And electrode engineering has been a useful method to facilitate carrier...The work function （WF） of indium-tin-oxide （ITO） substrates plays an important role on the inverted organic photovoltaic device performance. And electrode engineering has been a useful method to facilitate carrier extraction or charge collection to enhance organic photovoltaic （OPV） performance. By using self-assembly technique, we have deposited poly（dimethyl diallylammonium chloride） （PDDA） layers onto ITO coated glass substrates. The results indicate that the surface WF of ITO is reduced by about 0.3 eV after PDDA modification, which is attributed to the modulation in electron affinity. In addition, the surface roughness of ITO substrate became smaller after PDDA modification. These modified ITO substrates can be applied to fabricate inverted OPVs, in which ITO works as the cathode to collect electrons. As a result, the photovoltaic performance of inverted OPV is substantially improved, mainly reflecting on the increase of short circuit current density.展开更多
Surface modification may be an effective means for controlling the properties of germanane, i.e., hydrogenated germanene. In this work, we investigate the formation, stability, structure and electronic properties of s...Surface modification may be an effective means for controlling the properties of germanane, i.e., hydrogenated germanene. In this work, we investigate the formation, stability, structure and electronic properties of surface-modified germanane that results from the hydrogermylation, alkoxylation, aminization or phenylation of germanane. By assuming the typical organic surface coverage of -33%, we have com- pared organically surface-modified germanane with germanene and germanane in the framework of density functional theory. It is found that organically surface-modified germanane may all stably exist despite the endothermic nature of organic surface modification. Organic surface modification leads to the de- crease of the Ge--Ge bond length and the Ge--Ge-Ge bond angle ofgermanane, while causing the buckling distance of germanane to increase. Hydrogenation makes germanene change from a semimetal to a direct- bandgap semiconductor. Organic surface modification further impacts the band structure of the resulting germanane. Hydrogermylated/alkoxylated germanane is a direct-bandgap semiconductor, while aminated/ phenylated germanane is an indirect-bandgap semiconductor. All the organic surface modification gives rise to the increase of the bandgap of germanane.展开更多
The severe shuttle effect problem of soluble polysulfides greatly hinders the development of long-life lithium-sulfur(Li-S)batteries,which can be improved by separator modification.This study develops a bilayer separa...The severe shuttle effect problem of soluble polysulfides greatly hinders the development of long-life lithium-sulfur(Li-S)batteries,which can be improved by separator modification.This study develops a bilayer separator based on an effective surface and structure dual modification strategy.This bilayer separator(named as TCNFs/SPNFs)is constructed by the integration of a carbon-based nanofiber layer(surface modification layer)with a polymer-based nanofiber layer(structure modification layer)through a facile electrospinning process.The excellent electrolyte wettability of the nanofibers accelerates lithium-ion migration,while the good electronic conductivity of the carbon layer facilitates fast electron conduction.The TiO_(2)and SiO_(2)nanoparticles embedded in the separator provide abundant active sites for immobilizing the polysulfides.Owing to these synergistic effects,this multi-functional separator helps inhibit the shuttling problem and thus enhances the active sulfur utilization.The as-prepared battery with the TCNFs/SPNFs separator delivers significantly enhanced the electrochemical performances,producing a low capacity decay rate of 0.061%per cycle at 1 C over 1000 cycles and an admirable rate capacity of 886.7 mAh g^(-1)at 2 C.Even with a high sulfur loading of 4.8 mg cm^(-2),a remarkable areal capacity of 6.0 mAh cm^(-2)is attained.This work is believed to provide a promising strategy to develop novel separators for high-performance Li-S batteries.展开更多
文摘应用扫描电镜(SEM)、X射线光电子能谱(XPS)和衰减全反射红外光谱(FTIR-ATR)等现代表面分析技术研究不同改性处理羊毛表面的化学和物理结构特性.SEM研究结果表明,经低温等离子体表面改性或特定化学改性后的羊毛鳞片表面呈现纳米尺度的沟槽和凹凸结构,应用Wenzel公式和Cassie and Baxter公式阐述了表面粗糙度与接触角的关系,揭示了羊毛表面改性对于提高拒水拒油整理效果的原因所在.XPS和FTIR-ATR研究表明,上述物理和化学的表面改性技术使羊毛表面的二硫键氧化断裂和表面类脂物质改性/除去,促进拒水拒油整理剂的吸附和固着.表面改性和拒水拒油整理的协同效应赋予羊毛类荷叶效应,使其呈现超级拒水拒油拒污功能.
基金supported by the National Basic Research Program of China (2015CB932302)the National Natural Science Foundation of China (U1432133, 11321503, 21701164)+2 种基金the National Young Top-Notch Talent Support Program, the Chinese Academy of Sciences (XDB01020300)the Fok Ying-Tong Education Foundation (141042)the Fundamental Research Funds for the Central Universities (WK2060190027, WK2060190058)
文摘Photocatalytic conversion efficiency is limited by serious charge carrier recombination. Efficient carrier separation is usually achieved by elegantly-designed multi-component structures connected by directional electric field. Herein, we developed a twodimensional(2 D) sandwich structure, as a new photocatalytic system, to realize high-efficiency carrier separation. This strategy integrated multifunction into a single structure for the first time, which successfully introduces a stable built-in electric field,realizing high-effective carrier separation. Besides, the carrier concentration is dramatically increased due to dimensional confinement. Benefiting from above synergic advantages, 2 D sandwich photocatalyst achieves the highest nitrogen fixation rate(435 μmol g^(-1) h^(-1)) in inorganic solid photocatalysts under visible light irradiation. We anticipate that 2 D sandwich photocatalyst holds promises for the application and expansion of 2 D materials in photocatalysis research.
基金Supported by the National Natural Science Fundation of China(Nos.20676049,20871058 and 20971028)the Foundation of Enterprise-University-Research Institute Cooperation from Guangdong Province and Ministry of Education of China(Nos. 2007B090400105 and 2008A010500005)
文摘Tetradecyldimethylbenzyl ammonium salt（TDMBA） cations were intercalated into sodium montmorillonite（Na-MMT） by an ion exchange reaction. The resulting TDMBA-MMT was characterized by Fourier-transform infrared spectroscopy（FTIR）, thermogravimetric analysis（TGA）, and X-ray diffraction（XRD）. Moreover, the antibacterial activity and water-resistance of TDMBA-MMT were investigated. The results show that TDMBA cations are intercalated into the Na-MMT. The onset temperature of decomposition of TDMBA cations in TDMBA-MMT is raised about 60 ℃ higher than that of tetradecyldimethylbenzyl ammonium chloride（TDMBACl）, and the d（001） spacing enlarged from 1.23 nm to 2.10 nm. 0.1 mg/mL TDMBA-MMT is fully enough to kill all the Staphylococci aureus（S, aureus） and more than 99.99% of the Escherichia coli（E, coli） in a sample solution within 6.0 h touch, and the TDMBA-MMT also shows long acting properties.
文摘The work function （WF） of indium-tin-oxide （ITO） substrates plays an important role on the inverted organic photovoltaic device performance. And electrode engineering has been a useful method to facilitate carrier extraction or charge collection to enhance organic photovoltaic （OPV） performance. By using self-assembly technique, we have deposited poly（dimethyl diallylammonium chloride） （PDDA） layers onto ITO coated glass substrates. The results indicate that the surface WF of ITO is reduced by about 0.3 eV after PDDA modification, which is attributed to the modulation in electron affinity. In addition, the surface roughness of ITO substrate became smaller after PDDA modification. These modified ITO substrates can be applied to fabricate inverted OPVs, in which ITO works as the cathode to collect electrons. As a result, the photovoltaic performance of inverted OPV is substantially improved, mainly reflecting on the increase of short circuit current density.
基金mainly supported by the National Basic Research Program of China(973 program,Grant No.2013CB632101)the National Natural Science Foundation of China(Grant Nos.61222404 and 61474097)Partial support is provided by the Fundamental Research Funds for Central Universities(Grant No.2014XZZX003-09)
文摘Surface modification may be an effective means for controlling the properties of germanane, i.e., hydrogenated germanene. In this work, we investigate the formation, stability, structure and electronic properties of surface-modified germanane that results from the hydrogermylation, alkoxylation, aminization or phenylation of germanane. By assuming the typical organic surface coverage of -33%, we have com- pared organically surface-modified germanane with germanene and germanane in the framework of density functional theory. It is found that organically surface-modified germanane may all stably exist despite the endothermic nature of organic surface modification. Organic surface modification leads to the de- crease of the Ge--Ge bond length and the Ge--Ge-Ge bond angle ofgermanane, while causing the buckling distance of germanane to increase. Hydrogenation makes germanene change from a semimetal to a direct- bandgap semiconductor. Organic surface modification further impacts the band structure of the resulting germanane. Hydrogermylated/alkoxylated germanane is a direct-bandgap semiconductor, while aminated/ phenylated germanane is an indirect-bandgap semiconductor. All the organic surface modification gives rise to the increase of the bandgap of germanane.
基金supported by the National Natural Science Foundation of China(Grant Nos.51975218 and U22A20193)the Natural Science Foundation of Guangdong Province(Grant No.2021A1515010642)+3 种基金Guangdong-Hong Kong Joint Innovation Project of Guangdong Province(Grant No.2021A0505110002)Guangdong-Foshan Joint Foundation(Grant No.2021B1515120031)the Innovation Group Project of Foshan(Grant No.2120001010816)the S&T Innovation Projects of Zhuhai City(Grant No.ZH01110405180034PWC)。
文摘The severe shuttle effect problem of soluble polysulfides greatly hinders the development of long-life lithium-sulfur(Li-S)batteries,which can be improved by separator modification.This study develops a bilayer separator based on an effective surface and structure dual modification strategy.This bilayer separator(named as TCNFs/SPNFs)is constructed by the integration of a carbon-based nanofiber layer(surface modification layer)with a polymer-based nanofiber layer(structure modification layer)through a facile electrospinning process.The excellent electrolyte wettability of the nanofibers accelerates lithium-ion migration,while the good electronic conductivity of the carbon layer facilitates fast electron conduction.The TiO_(2)and SiO_(2)nanoparticles embedded in the separator provide abundant active sites for immobilizing the polysulfides.Owing to these synergistic effects,this multi-functional separator helps inhibit the shuttling problem and thus enhances the active sulfur utilization.The as-prepared battery with the TCNFs/SPNFs separator delivers significantly enhanced the electrochemical performances,producing a low capacity decay rate of 0.061%per cycle at 1 C over 1000 cycles and an admirable rate capacity of 886.7 mAh g^(-1)at 2 C.Even with a high sulfur loading of 4.8 mg cm^(-2),a remarkable areal capacity of 6.0 mAh cm^(-2)is attained.This work is believed to provide a promising strategy to develop novel separators for high-performance Li-S batteries.
