scholarly journals Conjugated polymers templated carbonization to design N, S co-doped finely tunable carbon for enhanced synergistic catalysis

2022 ◽  
Vol 300 ◽  
pp. 120732
Author(s):  
Abdellah Ait El Fakir ◽  
Zakaria Anfar ◽  
Mohamed Enneiymy ◽  
Amane Jada ◽  
Noureddine El Alem
Keyword(s):  
Conjugated Polymers ◽  
Synergistic Catalysis ◽  
Co Doped

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

970 nm Infrared to Visible Upconversion in Er3+ and Yb3+ Co-Doped PLZT Glass Ceramic Thin Films

2008 ◽  
Author(s):  
Xiaomei Guo ◽  
Kewen Kevin. Li ◽  
Xuesheng Chen ◽  
Yingyin Kevin. Zou ◽  
Hua Jiang
Keyword(s):  
Thin Films ◽  
Glass Ceramic ◽  
Ceramic Thin Films ◽  
Co Doped

Oriented Luminescent Nanostructures From Single Molecules Of Conjugated Polymers

2003 ◽  
Vol 771 ◽  
Author(s):  
Adosh Mehta ◽  
Pradeep Kumar ◽  
Jie Zheng ◽  
Robert M. Dickson ◽  
Bobby Sumpter ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Polarization Anisotropy ◽  
Emission Pattern ◽  
Spectral Signatures ◽  
Dipole Emission ◽  
Ink Jet ◽  
Molecular Scale ◽  
Jet Printing ◽  
Photochemical Stability ◽  
Printing Techniques

AbstractDipole emission pattern imaging experiments on single chains of common conjugated polymers (solubilized poly phenylene vinylenes) isolated by ink-jet printing techniques have revealed surprising uniformity in transition moment orientation perpendicular to the support substrate. In addition to uniform orientation, these species show a number of striking differences in photochemical stability, polarization anisotropy,[1] and spectral signatures[2] with respect to similar (well-studied) molecules dispersed in dilute thin-films. Combined with molecular mechanics simulation, these results point to a structural picture of a folded macromolecule as a highly ordered cylindrical nanostructure whose long-axis (approximately collinear with the conjugation axis) is oriented, by an electrostatic interaction, perpendicular to the coverglass substrate. These results suggest a number of important applications in nanoscale photonics and molecular-scale optoelectronics.

Toward highly photoluminescent and bipolar charge-transporting conjugated polymers

2000 ◽  
Vol 154 (1) ◽  
pp. 245-252 ◽  
Author(s):  
Zhonghua Peng ◽  
Yongchun Pan ◽  
Bubin Xu ◽  
Jianheng Zhang
Keyword(s):  
Conjugated Polymers ◽  
Bipolar Charge

Regio-, Stereo- and Enantioselective α-Addition of Carbonyl Nucleo-philes to Allenamides Catalyzed by a Synergistic Copper/Enamine System

2020 ◽  
Author(s):  
Rémi Blieck ◽  
Sebastien Lemouzy ◽  
Marc Taillefer ◽  
Florian Monnier
Keyword(s):  
Catalytic System ◽  
Secondary Amine ◽  
Primary Amine ◽  
Synergistic Catalysis ◽  
Enantioselective Addition ◽  
Amine Catalysts

A dual copper/enamine catalytic system is found to enable an intermolecular enantioselective α-addition of various carbonyl nucleophiles to allenamides. Secondary amine catalysts allowed the highly enantioselective addition of aldehydes, while using primary amine catalysts led to the enantioselective addition of ketoester nucleophiles. The process was found to be highly regio-, stereo- and enantio-selective and represented the first allene hydrofunctionalization using an synergistic catalysis involving copper

Tunable Carbon Surface from Mono- to Multi-Metallic Single Atoms

2020 ◽  
Author(s):  
Weihong Lai ◽  
Heng Wang ◽  
Quan jiang ◽  
Zichao Yan ◽  
Hanwen Liu ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Structural Evolution ◽  
Charge Compensation ◽  
Catalytic Reactions ◽  
Single Atom ◽  
Carbon Surface ◽  
Hydrogen Electrode ◽  
Single Atoms ◽  
Mass Activity ◽  
Co Doped

<p>Herein, we develop a non-selective charge compensation strategy to prepare multi-single-atom doped carbon (MSAC) in which a sodium p-toluenesulfonate (PTS-Na) doped polypyrrole (S-PPy) polymer is designed to anchor discretionary mixtures of multiple metal cations, including iron (Fe<sup>3+</sup>), cobalt (Co<sup>3+</sup>), ruthenium (Ru<sup>3+</sup>), palladium (Pd<sup>2+</sup>), indium (In<sup>3+</sup>), iridium (Ir<sup>2+</sup>), and platinum (Pt<sup>2+</sup>) . As illustrated in Figure 1, the carbon surface can be tuned with different level of compositional complexities, including unary Pt<sub>1</sub>@NC, binary (MSAC-2, (PtFe)<sub>1</sub>@NC), ternary (MSAC-3, (PtFeIr)<sub>1</sub>@NC), quaternary (MSAC-4, (PtFeIrRu)<sub>1</sub>@NC), quinary (MSAC-5, (PtFeIrRuCo)<sub>1</sub>@NC), senary (MSAC-6, (PtFeIrRuCoPd)<sub>1</sub>@NC), and septenary (MSAC-7, (PtFeIrRuCoPdIn)<sub>1</sub>@NC) samples. The structural evolution of carbon surface dictates the activities of both ORR and HER. The senary MSAC-6 achieves the ORR mass activity of 18.1 A·mg<sub>metal</sub><sup>-1</sup> at 0.9 V (Vs reversible hydrogen electrode (RHE)) over 30K cycles, which is 164 times higher than that of commercial Pt/C. The quaternary MSAC-4 presented a comparable HER catalytic capability with that of Pt/C. These results indicate that the highly complexed carbon surface can enhance its ability over general electrochemical catalytic reactions. The mechanisms regarding of the ORR and HER activities of the alternated carbon surface are also theoretically and experimentally investigated in this work, showing that the synergistic effects amongst the co-doped atoms can activate or inactivate certain single-atom sites.</p>

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