Effects of Copper Substitution by Alkali Metals on the Properties of Chalcopyrites for Tandem Applications: Insights from Theory

2020 ◽  
Vol 124 (19) ◽  
pp. 10353-10366 ◽  
Author(s):  
Fabien Lafond ◽  
Philippe Baranek ◽  
Andrei Postnikov
Keyword(s):  
Alkali Metals ◽  
Copper Substitution

Room Temperature Alkali Metal Reduction of Carbon Dioxide

2020 ◽  
Author(s):  
Lucas A. Freeman ◽  
Akachukwu D. Obi ◽  
Haleigh R. Machost ◽  
Andrew Molino ◽  
Asa W. Nichols ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Alkali Metals ◽  
Room Temperature ◽  
Chemical Reduction ◽  
Bond Cleavage ◽  
Open Shell ◽  
Metal Reduction ◽  
One Pot ◽  
Earth Abundant ◽  
Electron Reduction

The reduction of the relatively inert carbon–oxygen bonds of CO<sub>2</sub> to access useful CO<sub>2</sub>-derived organic products is one of the most important fundamental challenges in synthetic chemistry. Facilitating this bond-cleavage using earth-abundant, non-toxic main group elements (MGEs) is especially arduous because of the difficulty in achieving strong inner-sphere interactions between CO<sub>2</sub> and the MGE. Herein we report the first successful chemical reduction of CO<sub>2</sub> at room temperature by alkali metals, promoted by a cyclic(alkyl)(amino) carbene (CAAC). One-electron reduction of CAAC-CO<sub>2</sub> adduct (<b>1</b>) with lithium, sodium or potassium metal yields stable monoanionic radicals clusters [M(CAAC–CO<sub>2</sub>)]<sub>n</sub>(M = Li, Na, K, <b> 2</b>-<b>4</b>) and two-electron alkali metal reduction affords open-shell, dianionic clusters of the general formula [M<sub>2</sub>(CAAC–CO<sub>2</sub>)]<sub>n </sub>(<b>5</b>-<b>8</b>). It is notable that these crystalline clusters of reduced CO<sub>2</sub> may also be isolated via the “one-pot” reaction of free CO<sub>2</sub> with free CAAC followed by the addition of alkali metals – a reductive process which does not occur in the absence of carbene. Each of the products <b>2</b>-<b>8</b> were investigated using a combination of experimental and theoretical methods.<br>

scholarly journals The influence of active carbon contaminants on the ozonation mechanism interpretation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lilla Fijołek ◽  
Joanna Świetlik ◽  
Marcin Frankowski
Keyword(s):  
Activated Carbon ◽  
Active Carbon ◽  
Alkali Metals ◽  
Activated Carbons ◽  
Carbon Surface ◽  
Bulk Solution ◽  
Ozone Decomposition ◽  
Reaction Products ◽  
Treatment Technology ◽  
Carbon Impurities

AbstractIn water treatment technology, activated carbons are used primarily as sorbents to remove organic impurities, mainly natural organic matter, but also as catalysts in the ozonation process. Commercially available activated carbons are usually contaminated with mineral substances, classified into two main groups: alkali metals (Ca, Na, K, Li, Mg) and multivalent metals (Al, Fe, Ti, Si). The presence of impurities on the carbon surface significantly affects the pHpzc values determined for raw and ozonated carbon as well as their acidity and alkalinity. The scale of the observed changes strongly depends on the pH of the ozonated system, which is related to the diffusion of impurities from the carbon to the solution. In an acidic environment (pH 2.5 in this work), the ozone molecule is relatively stable, yet active carbon causes its decomposition. This is the first report that indirectly indicates that contaminants on the surface of activated carbon (multivalent elements) contribute to the breakdown of ozone towards radicals, while the process of ozone decomposition by purified carbons does not follow the radical path in bulk solution. Carbon impurities also change the distribution of the reaction products formed by organic pollutants ozonation, which additionally confirms the radical process. The study showed that the use of unpurified activated carbon in the ozonation of succinic acid (SA) leads to the formation of a relatively large amount of oxalic acid (OA), which is a product of radical SA degradation. On the other hand, in solutions with purified carbon, the amount of OA generated is negligible.

scholarly journals Link between Alkali Metals in Salt Templates and in Electrolytes for Improved Carbon-Based Electrochemical Capacitors

2021 ◽  
Vol 13 (2) ◽  
pp. 2584-2599
Author(s):  
Anetta Platek-Mielczarek ◽  
Cristina Nita ◽  
Camélia Matei Ghimbeu ◽  
Elzbieta Frackowiak ◽  
Krzysztof Fic
Keyword(s):  
Alkali Metals ◽  
Electrochemical Capacitors ◽  
Carbon Based

Cation-Induced Dimerization of Crown-Substituted Gallium Phthalocyanine by Complexing with Alkali Metals: The Crucial Role of a Central Metal

2021 ◽  
Vol 60 (3) ◽  
pp. 1948-1956
Author(s):  
Lyudmila A. Lapkina ◽  
Anna A. Sinelshchikova ◽  
Kirill P. Birin ◽  
Vladimir E. Larchenko ◽  
Mikhail S. Grigoriev ◽  
...  
Keyword(s):  
Crucial Role ◽  
Alkali Metals ◽  
Central Metal

scholarly journals Rb intercalation enhanced the supercapacitive performance of layer-structured MoS2 as a 2D model material

2021 ◽  
Author(s):  
Ahmed H Biby ◽  
Basant A. Ali ◽  
Nageh Allam
Keyword(s):  
Energy Storage ◽  
Alkali Metals ◽  
2D Materials ◽  
Model Material ◽  
Supercapacitive Performance ◽  
Storage Performance ◽  
2D Model

Intercalation of alkali metals has proved to be an effective approach for the enhancement of the energy storage performance in layered-2D materials. However, the research so far has been limited...

scholarly journals Tellurene: Alloying of Alkali Metals with Tellurene (Adv. Energy Mater. 7/2021)

2021 ◽  
Vol 11 (7) ◽  
pp. 2170029
Author(s):  
Rishabh Jain ◽  
Yifei Yuan ◽  
Yashpal Singh ◽  
Swastik Basu ◽  
Dawei Wang ◽  
...  
Keyword(s):  
Alkali Metals ◽  
Energy Mater
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