Solvent-Mediated Engineering of Copper-Metalated Acetylenic Polymer Scaffolds with Enhanced Photoelectrochemical Performance

Author(s):  
Tao Zhang ◽  
Zhongquan Liao ◽  
Ehrenfried Zschech ◽  
Guoliang Chai ◽  
Yang Hou ◽  
...  

The covalent linking of acetylenes presents an important route for the fabrication of novel carbon-based scaffolds with potential utilities in a large variety of applications. Beyond that, the incorporation of...

Author(s):  
B. K. Kirchoff ◽  
L.F. Allard ◽  
W.C. Bigelow

In attempting to use the SEM to investigate the transition from the vegetative to the floral state in oat (Avena sativa L.) it was discovered that the procedures of fixation and critical point drying (CPD), and fresh tissue examination of the specimens gave unsatisfactory results. In most cases, by using these techniques, cells of the tissue were collapsed or otherwise visibly distorted. Figure 1 shows the results of fixation with 4.5% formaldehyde-gluteraldehyde followed by CPD. Almost all cellular detail has been obscured by the resulting shrinkage distortions. The larger cracks seen on the left of the picture may be due to dissection damage, rather than CPD. The results of observation of fresh tissue are seen in Fig. 2. Although there is a substantial improvement over CPD, some cell collapse still occurs.Due to these difficulties, it was decided to experiment with cold stage techniques. The specimens to be observed were dissected out and attached to the sample stub using a carbon based conductive paint in acetone.


2020 ◽  
Author(s):  
Idoia Hita ◽  
Tomas Cordero-Lanzac ◽  
Francisco J. Garcia-Mateos ◽  
Jose Rodriguez-Mirasol ◽  
Tomas Cordero ◽  
...  

2020 ◽  
Author(s):  
Idoia Hita ◽  
Tomas Cordero-Lanzac ◽  
Francisco J. Garcia-Mateos ◽  
Jose Rodriguez-Mirasol ◽  
Tomas Cordero ◽  
...  

2019 ◽  
Author(s):  
Zhen Liu ◽  
Xiaohan Li ◽  
Tian Zeng ◽  
Keary Engle

A substrate-directed enantioselective <i>anti</i>-carboboration reaction of alkenes has been developed, wherein a carbon based nucleophile and a boron moiety are installed across the C=C bond through a 5- or 6-membered palladacycle intermediate. The reaction is promoted by a palladium(II) catalyst and a mondentate oxzazoline ligand. A range of enantioenriched secondary alkylboronate products were obtained with moderate to high enantioselectivity that could be further upgraded by recrystallization. This work represents a new method to synthesize versatile and valuable alkylboronate building blocks. Building on an earlier mechanistic proposal by Peng, He, and Chen, a revised model is proposed to account for the stereoconvergent nature of this transformation.


2019 ◽  
Author(s):  
Jiajia Tao ◽  
Hong-Ping Ma ◽  
Kaiping Yuan ◽  
Yang Gu ◽  
Jianwei Lian ◽  
...  

<div>As a promising oxygen evolution reaction semiconductor, TiO2 has been extensively investigated for solar photoelectrochemical water splitting. Here, a highly efficient and stable strategy for rationally preparing GaON cocatalysts on TiO2 by atomic layer deposition is demonstrated, which we show significantly enhances the</div><div>photoelectrochemical performance compared to TiO2-based photoanodes. For TiO2@20 nm-GaON core-shell nanowires a photocurrent density up to 1.10 mA cm-2 (1.23 V vs RHE) under AM 1.5 G irradiation (100 mW cm-2) has been achieved, which is 14 times higher than that of TiO2 NWs. Furthermore, the oxygen vacancy formation on GaON as well as the band gap matching with TiO2 not only provides more active sites for water oxidation but also enhances light absorption to promote interfacial charge separation and migration. Density functional theory studies of model systems of GaON-modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaON core-shell nanowires provide a deeper understanding and universal strategy for enhancing photoelectrochemical performance of photoanodes now available. </div>


2012 ◽  
Vol 11 (3) ◽  
pp. 627-634 ◽  
Author(s):  
Florica Manea ◽  
Sorina Motoc ◽  
Aniela Pop ◽  
Rodica Pode ◽  
Carmen Teodosiu

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