scholarly journals Synthesis and self-assembly of thiol-modified tellurophenes

2018 ◽  
Vol 96 (10) ◽  
pp. 929-933 ◽  
Author(s):  
Gabrielle C. Hoover ◽  
Jennifer Ham ◽  
Connie Tang ◽  
Elisa I. Carrera ◽  
Dwight S. Seferos

An asymmetric thiol-modified tellurophene was designed and synthesized, and the ability of the compound to form a monolayer on a gold electrode was confirmed. The surface-active tellurophene was synthesized using Cadiot–Chodkiewicz coupling followed by ring closing and thiol modification. The tellurophene compound forms a monolayer on gold surfaces from a concentrated solution within 24 h. The ability of the compound to conjugate to gold is confirmed by X-ray photoelectron spectroscopy (XPS). A surface blocking experiment was used to evaluate the extent of formation of a monolayer on a gold electrode.

2015 ◽  
Vol 19 (09) ◽  
pp. 1014-1020 ◽  
Author(s):  
Rudy Martin-Trasanco ◽  
Roberto Cao ◽  
Franz-Peter Montforts

The synthesis of a new carbonyl ruthenium(II) deuteroporphyrin-IX lipoic acid derivative (Ru(PLip)(CO)) (4) and its self-assembly on Au(111) surfaces were accomplished. Ru(PLip)(CO) 4 was prepared by reduction of the ester groups of carbonyl-ruthenium(II) deuteroporphyrindimethylester 1 and further esterification with D,L-α-lipoic acid 3. The self-assembly of Ru(PLip)(CO) 4 was confirmed by X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). The S2p XP spectrum of SAM formed by Ru(PLip)(CO) showed the S2p3/2 peak at 162.4 eV which corresponds to thiolated species bounded to gold. The influence of the interaction of porphyrin moieties on SAM stability was studied. The reductive desorption voltammogram of Ru(PLip)(CO) 4 self-assembled on gold showed an intense reduction peak at -1.02 V while when pyridine was coordinated to the central ruthenium(II) the reductive desorption peak was shifted to -0.85 V. The capacity of the modified Ru(PLip)(CO) gold electrode to detect nitric oxide (NO) was investigated by cyclic voltammetry. An irreversible reduction peak which increased with time on NO exposure was registered at -0.69 V indicating NO coordination to ruthenium(II).


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Tae Hyeong Kim ◽  
Hyeji Kim ◽  
Hyo Jun Jang ◽  
Nara Lee ◽  
Kwang Hyun Nam ◽  
...  

AbstractIn the study reported herein, silver-coated copper (Ag/Cu) powder was modified with alkanethiols featuring alkyl chains of different lengths, namely butyl, octyl, and dodecyl, to improve its thermal stability. The modification of the Ag/Cu powders with adsorbed alkanethiols was confirmed by scanning electron microscopy with energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Each powder was combined with an epoxy resin to prepare an electrically conductive film. The results confirmed that the thermal stability of the films containing alkanethiol-modified Ag/Cu powders is superior to that of the film containing untreated Ag/Cu powder. The longer the alkyl group in the alkanethiol-modified Ag/Cu powder, the higher the initial resistance of the corresponding electrically conductive film and the lower the increase in resistance induced by heat treatment.


2009 ◽  
Vol 13 (01) ◽  
pp. 35-40 ◽  
Author(s):  
Rudy Martin ◽  
Roberto Cao ◽  
Ana M. Esteva ◽  
Franz-Peter Montforts

A new ruthenium(II) porphyrin disulphide derivative, [ Ru ( Pds )( CO )], was obtained from ruthenium(II)(carbonyl)deuteroporphyrin(IX), [ Ru ( DPdc )( CO )] and cystamine. The interaction of this complex with nitric oxide was studied spectrophotometrically and a bathochromic shift of the charge transfer band and considerable change in the α and β bands of the complex were observed. According to the IR spectrum, the product of this interaction is [ Ru ( DmDP )( NO +)( NO 2-)]. [ Ru ( Pds )( CO )] was then self-assembled on polycrystalline gold and characterized by X-ray photoelectron spectroscopy. [ Ru ( Pds )( CO )] was also self-assembled on gold electrode beads and its interaction with nitric oxide in aqueous solution was studied by cyclic voltammetry. A shift in the ruthenium redox process and a new irreversible cathodic peak at -0.59 V were observed, both indicating coordination of NO .


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Yang Dang ◽  
Yu Cheng ◽  
Yukun Zhou ◽  
Yifei Huang ◽  
Kaige Wang

The treatment of organic dye contaminants in wastewaters has now becoming more imperative. Fenton-like degradation of methylene blue (MB) and methyl orange (MO) in aqueous solution was investigated by using a nanostructure that a layer of CuCl2 nanoflake film grown on the top surface of nanoporus anodic alumina substrate (nano-PAA-CuCl2) as catalyst. The new nano-PAA-CuCl2 composite was fabricated with self-assembly approach, that is, a network porous structure film composed of CuCl2 nanoflake grown on the upper surface of nanoporous anodic alumina substrate, and the physical and chemical properties are characterized systematically with the X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscopy (HRTEM), Energy Dispersive Spectrometer (EDS), X-ray photoelectron spectroscopy (XPS). The experimental results showed that the nano-PAA-CuCl2 catalyst presented excellent properties for the degradation of two typical organic pollutants such as MB and MO, which were almost completely degraded with 8 × 10−4mol/L nano-PAA-CuCl2 catalyst after 46 min and 60 min at reaction conditions of H2O2 18 mM and 23 mM, respectively. The effects of different reaction parameters such as initial pH, H2O2 concentration, catalyst morphology and temperature were attentively studied. And more, the stability and reusability of nano-PAA-CuCl2 were examined. Finally, the mechanism of MB and MO degradation by the nano-PAA-CuCl2/H2O2 system was proposed, based on the experimental data of the BCA and the temperature-programmed reduction (H2-TPR) and theoretical analysis, the reaction kinetics belonged to the pseudo-first-order equation. This new nanoporous composite material and preparation technology, as well as its application in Fenton-like reaction, provide an effective alternative method with practical application significance for wastewater treatment.


1998 ◽  
Vol 14 (01) ◽  
pp. 57-62
Author(s):  
Xiao Zhong-Dang ◽  
◽  
Huang Dan ◽  
Gu Jian-Hua ◽  
Lu Zu-Hong

2004 ◽  
Vol 830 ◽  
Author(s):  
Scott K. Stanley ◽  
Shawn S. Coffee ◽  
John G. Ekerdt

ABSTRACTGeH4 is thermally cracked over a hot filament depositing 0.7–15 ML Ge onto 2–7 nm SiO2/Si(100) at substrate temperatures of 300–970 K. Ge, GeHx, GeO, and GeO2 desorption is monitored through temperature programmed desorption in the temperature range 300–1000 K. Ge bonding changes are analyzed during annealing from 300–1000 K with X-ray photoelectron spectroscopy (XPS). Low temperature desorption features are attributed to GeO and GeH4. No GeO2 desorption is observed, but GeO2 decomposition to Ge through high temperature pathways is seen above 700 K. Germanium oxidization results from Ge etching of the oxide substrate, which is demonstrated through XPS. Ge nanoparticle formation on SiO2 is demonstrated using the agglomeration process. With these results, explanations for the difficulties of conventional chemical vapor deposition to produce Ge nanocrystals on SiO2 surfaces are proposed.


Langmuir ◽  
1996 ◽  
Vol 12 (21) ◽  
pp. 5083-5086 ◽  
Author(s):  
David G. Castner ◽  
Kenneth Hinds ◽  
David W. Grainger

2010 ◽  
Vol 25 (1) ◽  
pp. 182-188 ◽  
Author(s):  
Xiaoxia Yan ◽  
Gang Liu ◽  
Lianzhou Wang ◽  
Yong Wang ◽  
Xianfang Zhu ◽  
...  

Aimed at designing an efficient visible light active photocatalyst and suppressing the self-corrosion tendency of CdS nanoparticles, a novel composite consisting of CdS nanoparticles and exfoliated two-dimensional (2D) TiO2 nanosheets was successfully fabricated using a simple self-assembly process. The prepared samples were characterized using various techniques including x-ray diffraction, ultraviolet–visible absorption spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. It was found that the exfoliated 2D nanosheets played an important role as an ultrathin coating to suppress the photocorrosion of CdS nanoparticles, evidenced by inductively coupled plasma-atomic emission spectrometer analysis. The resultant CdS/TiO2 composites exhibited enhanced photocatalytic activity in the oxidation of Rhodamine B in water under visible light irradiation (λ > 420 nm).


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