In the paper, two kinds of CdS nanorods with diameter of 50-150 nm were synthesized by using amphiphilic alanine as the templating reagent. XRD, TEM and polarized light microscopy were used to examine the course of Cd...In the paper, two kinds of CdS nanorods with diameter of 50-150 nm were synthesized by using amphiphilic alanine as the templating reagent. XRD, TEM and polarized light microscopy were used to examine the course of CdS growth. The nanorod with a hexagonal pore microstructure was fabricated when the mesophase exhibited hexagonal morphology of the polarized light microscopy image. The XRD pattern of the nanorods with hexagonal pore microstructure showed a clear peak in 2θ=0.88° which suggested the existence of hexagonal pore. While the mesophase disappeared and isotropic polarized light microscopy image shows that CdS would propagate into nanorod without hexagonal pore. It was deduced that nanorods with hexagonal pore grow in the hole of hexagonal liquid crystal and those CdS growth without hexagonal pore are in isotropic solution by the absorption of amphilphilic alanine. It was suggested that different nanostructures could be generated under various chemical micro-environments to reveal their special functionalities.展开更多
CdS nanorods have been sorted by length using a density gradient ultracentrifuge rate separation method. The fractions containing longer rods showed relatively stronger oxygen-related surface trap emission, while the ...CdS nanorods have been sorted by length using a density gradient ultracentrifuge rate separation method. The fractions containing longer rods showed relatively stronger oxygen-related surface trap emission, while the shorter ones had dominant band-edge emission. These results suggest that the final length distribution of CdS nanorods is not a result of random nucleation and growth, but is related to the local synthesis conditions. Inspired by these findings, different synthesis environments （N2, air, and 02） have been employed in order to tailor the length distribution. In addition to the rod length, the photoluminescence properties of CdS nanorods can also be manipulated. Increasing the oxygen partial pressure significantly changed the growth behavior of CdS nanorods by improving the anisotropic growth.展开更多
1-dimensional (1D) metal-semiconductor nano-scale composite superstructures based on Au nanoparticles and CdS nanorods were prepared.The outer surface of CdS nanorods was modified with mercapto-ethylamine (MEA) in adv...1-dimensional (1D) metal-semiconductor nano-scale composite superstructures based on Au nanoparticles and CdS nanorods were prepared.The outer surface of CdS nanorods was modified with mercapto-ethylamine (MEA) in advance.With the aid of MEA,dense and uniform Au nanoparticles were deposited onto the external wall of CdS nanorods through in situ chemical reduction of AuCl4-ions.Those Au nanoparticles induced further electroless deposition and a continuous layer of Au was formed on CdS nanorods.Stable hollow Au tubes were obtained after the inner CdS cores were etched by HCl.UV-Vis,FL,XPS,EDX,TEM and SEM measurements were carried out to characterize the produced materials.The quenching of the defect emission of CdS in CdS-nanorod/Au-nanoparticle hybrid superstructures was detected,which was ascribed to the energy transfer from the exciton of CdS to surface plasma resonance level of Au.展开更多
Anchoring molecular cocatalysts on semiconductors has been recognized as a general strategy to boost the charge separation efficiency required for efficient photocatalysis.However,the effect of molecular cocatalysts o...Anchoring molecular cocatalysts on semiconductors has been recognized as a general strategy to boost the charge separation efficiency required for efficient photocatalysis.However,the effect of molecular cocatalysts on energy funneling(i.e.,directional energy transfer)inside semiconductor photocatalysts has not been demonstrated yet.Here we prepared CdS nanorods with both thin and thick rods and anchored the conjugated molecules 2‐mercaptobenzimidazole(MBI)and cobalt molecular catalysts(MCoA)sequentially onto the surface of nanorods.Transient absorption measurements revealed that MBI molecules facilitated energy funneling from thin to thick rods by the electronic coupling between thin and thick nanorods,which is essentially a light‐harvesting antenna approach to enhance the charge generation efficiency in the reaction center(here the thick rods).Moreover,MBI and MCoA molecules selectively extracted photogenerated holes and electrons of CdS nanorods rapidly,leading to efficient charge separation.Consequently,CdS/MBI/MCoA displayed 15 times enhanced photocatalytic H_(2) evolution(1.65 mL)than pure CdS(0.11 mL)over 3 h of illumination.The amount of H_(2) evolution reached 60 mL over 48 h of illumination with a high turnover number of 26294 and an apparent quantum efficiency of 71%at 420 nm.This study demonstrates a novel design principle for next‐generation photocatalysts.展开更多
南京大学化学化工学院生命分析化学国家重点实验室王伟课题组提出了一种倒易空间角度谱方法实现了单个CdS纳米棒空间取向的实时、原位测量。此项成果于2019年3月14日以"Tracking the rotation of single CdS nanorods during photo...南京大学化学化工学院生命分析化学国家重点实验室王伟课题组提出了一种倒易空间角度谱方法实现了单个CdS纳米棒空间取向的实时、原位测量。此项成果于2019年3月14日以"Tracking the rotation of single CdS nanorods during photocatalysis with surface plasmon resonance microscopy"为题在线发表于《美国科学院院刊》(Proc.Natl.Acad.Sci.USA,DOI:10.1073/pnas.1820114116).展开更多
文摘In the paper, two kinds of CdS nanorods with diameter of 50-150 nm were synthesized by using amphiphilic alanine as the templating reagent. XRD, TEM and polarized light microscopy were used to examine the course of CdS growth. The nanorod with a hexagonal pore microstructure was fabricated when the mesophase exhibited hexagonal morphology of the polarized light microscopy image. The XRD pattern of the nanorods with hexagonal pore microstructure showed a clear peak in 2θ=0.88° which suggested the existence of hexagonal pore. While the mesophase disappeared and isotropic polarized light microscopy image shows that CdS would propagate into nanorod without hexagonal pore. It was deduced that nanorods with hexagonal pore grow in the hole of hexagonal liquid crystal and those CdS growth without hexagonal pore are in isotropic solution by the absorption of amphilphilic alanine. It was suggested that different nanostructures could be generated under various chemical micro-environments to reveal their special functionalities.
基金International Cooperation Project of Guizhou Province(2012-7002)National Science Foundation of Guizhou Province(2014-2059)+1 种基金Science Research Plan of Guizhou Province of China(2012-3005,2010-4005,2009-15,2010-2134,2011-2016)National Science Foundation of China(11364005)
文摘CdS nanorods have been sorted by length using a density gradient ultracentrifuge rate separation method. The fractions containing longer rods showed relatively stronger oxygen-related surface trap emission, while the shorter ones had dominant band-edge emission. These results suggest that the final length distribution of CdS nanorods is not a result of random nucleation and growth, but is related to the local synthesis conditions. Inspired by these findings, different synthesis environments （N2, air, and 02） have been employed in order to tailor the length distribution. In addition to the rod length, the photoluminescence properties of CdS nanorods can also be manipulated. Increasing the oxygen partial pressure significantly changed the growth behavior of CdS nanorods by improving the anisotropic growth.
基金supported by the National Natural Science Foundation of China (Grant No.90406018)Ministry of Science and Technology of China (Grant Nos.2006CB0N0403 and 2007CB936202)
文摘1-dimensional (1D) metal-semiconductor nano-scale composite superstructures based on Au nanoparticles and CdS nanorods were prepared.The outer surface of CdS nanorods was modified with mercapto-ethylamine (MEA) in advance.With the aid of MEA,dense and uniform Au nanoparticles were deposited onto the external wall of CdS nanorods through in situ chemical reduction of AuCl4-ions.Those Au nanoparticles induced further electroless deposition and a continuous layer of Au was formed on CdS nanorods.Stable hollow Au tubes were obtained after the inner CdS cores were etched by HCl.UV-Vis,FL,XPS,EDX,TEM and SEM measurements were carried out to characterize the produced materials.The quenching of the defect emission of CdS in CdS-nanorod/Au-nanoparticle hybrid superstructures was detected,which was ascribed to the energy transfer from the exciton of CdS to surface plasma resonance level of Au.
文摘Anchoring molecular cocatalysts on semiconductors has been recognized as a general strategy to boost the charge separation efficiency required for efficient photocatalysis.However,the effect of molecular cocatalysts on energy funneling(i.e.,directional energy transfer)inside semiconductor photocatalysts has not been demonstrated yet.Here we prepared CdS nanorods with both thin and thick rods and anchored the conjugated molecules 2‐mercaptobenzimidazole(MBI)and cobalt molecular catalysts(MCoA)sequentially onto the surface of nanorods.Transient absorption measurements revealed that MBI molecules facilitated energy funneling from thin to thick rods by the electronic coupling between thin and thick nanorods,which is essentially a light‐harvesting antenna approach to enhance the charge generation efficiency in the reaction center(here the thick rods).Moreover,MBI and MCoA molecules selectively extracted photogenerated holes and electrons of CdS nanorods rapidly,leading to efficient charge separation.Consequently,CdS/MBI/MCoA displayed 15 times enhanced photocatalytic H_(2) evolution(1.65 mL)than pure CdS(0.11 mL)over 3 h of illumination.The amount of H_(2) evolution reached 60 mL over 48 h of illumination with a high turnover number of 26294 and an apparent quantum efficiency of 71%at 420 nm.This study demonstrates a novel design principle for next‐generation photocatalysts.
文摘南京大学化学化工学院生命分析化学国家重点实验室王伟课题组提出了一种倒易空间角度谱方法实现了单个CdS纳米棒空间取向的实时、原位测量。此项成果于2019年3月14日以"Tracking the rotation of single CdS nanorods during photocatalysis with surface plasmon resonance microscopy"为题在线发表于《美国科学院院刊》(Proc.Natl.Acad.Sci.USA,DOI:10.1073/pnas.1820114116).
