scholarly journals About perspectives of photocatalytic reduction of metals from natural and man-made solutions

2020 ◽  
Author(s):  
Д.С. ШТАРЕВ ◽  
А.В. ШТАРЕВА ◽  
Н.В. БЕРДНИКОВ
Keyword(s):  
Aqueous Solutions ◽  
Visible Light ◽  
Alkaline Earth ◽  
Selective Reduction ◽  
Alkaline Earth Metals ◽  
Photocatalytic Reduction ◽  
Experimental Results ◽  
Experimental Conditions

Обсуждаются результаты экспериментов по фотокаталитическому восстановлению металлов из растворов в присутствии фотокатализаторов видимого света на основе висмутатов щелочноземельных металлов. Показано, что наибольшее количество изученных металлов успешно восстанавливается из растворов в присутствии Ca5Bi14O26. Наименее подверженными фотокаталитическому восстановлению оказались Li, B, Na, Al, Ca, Fe, Ba, W, Re. Наименее эффективным для восстановления металлов из растворов при данных условиях эксперимента оказался фотокатализатор Sr3Bi2O6. Обоснована перспективность фотокатализа для селективного восстановления и выделения ниобия и тантала из водных растворов. Большинство элементов после восстановления удаляются из раствора, по-видимому, оседая на фотокатализаторе и стенках реактора. Восстановленное золото коагулирует в частицы, образующие в растворе взвесь. Результаты экспериментов свидетельствуют о перспективности исследования фотокатализаторов видимого света на основе висмутатов щелочноземельных металлов для разработки технологий очистки природных и техногенных растворов с получением из них ценных компонентов. The results of experiments on the photocatalytic reduction of metals from solutions in the presence of visible light photocatalysts based on bismuthates of alkaline earth metals are discussed. It is shown that the largest number of studied metals is successfully reduced from solutions in the presence of Ca5Bi14O26. The least prone to photocatalytic reduction were Li, B, Na, Al, Ca, Fe, Ba, W, Re. The Sr3Bi2O6 photocatalyst was the least effective for the recovery of metals from solutions under these experimental conditions. The prospects of photocatalysis for the selective reduction and isolation of niobium and tantalum from aqueous solutions are justified. Most of the elements after recovery are removed from the solution, apparently, deposited on the photocatalyst and the walls of the reactor. Reduced gold coagulates into particles, forming a suspension in solution. The experimental results indicate the promise of research on visible-light photocatalysts based on bismuthates of alkaline earth metals for the development of technologies for the purification of natural and man-made solutions to produce valuable components from them.

Release Rules of Alkali and Alkaline Earth Metals during Coal Gasification in CO2 and O2/CO2

2011 ◽  
Vol 396-398 ◽  
pp. 1206-1209
Author(s):  
Jian Ying Lin ◽  
Yang Liu ◽  
Yu Qiao
Keyword(s):  
Oxygen Concentration ◽  
Ion Chromatography ◽  
Release Rate ◽  
Alkaline Earth ◽  
Coal Gasification ◽  
Alkaline Earth Metals ◽  
Release Rates ◽  
Experimental Conditions

Release rules of alkali and alkaline earth metals during coal gasification in CO2and O2/CO2are studied with fix-bed reactor and ion chromatography. The results show that the release rates of Na, K and Mg increase with the increase of temperature. Temperature has almost no effect on the release rate of Ca under the experimental conditions. Compare with temperature, Oxygen concentration has less effect on AAEM volatilization. The release rates of Na and K are higher than that of Mg and Ca. This indicates that the primary mechanisms of volatilization of Na and K are different from those of Mg and Ca.

scholarly journals Die Kristallstrukturen von Strontium- und Bariumhexacyanoferrat(III)-Hexamethylentetramin-Hydraten. Strukturmodell für Additionsverbindungen der Alkali- und Erdalkalimetallhexacyanoferrate mit Hexamethylentetramin / The Crystal Structures of Hydrates of Strontium and Barium Hexacyanoferrate(III) with Hexamethylenetetramine. Structural Model for Adducts of the Hexacyanoferrates of Alkaline and Alkaline Earth Metals with Hexamethylenetetramine

1989 ◽  
Vol 44 (5) ◽  
pp. 519-525 ◽  
Author(s):  
Hans-Jürgen Meyer ◽  
Joachim Pickardt
Keyword(s):  
Aqueous Solutions ◽  
Crystal Structures ◽  
General Formula ◽  
Alkaline Earth ◽  
Structural Model ◽  
Earth Metal ◽  
Alkaline Earth Metals ◽  
Alkaline Earth Metal ◽  
Monoclinic Space Group ◽  
Space Group

By reaction of methanolic solutions of hexamethylenetetramine with aqueous solutions of hexacyanoferrates(III) of strontium and barium resp., crystals of the compounds were obtained. Sr3[Fe(CN)6]2 · 3 C6H12N4 · 18 H2O, tetragonal, space group P42/nmc, Z = 4, a = 1931.8(4), c = 1579.9(4) pm, 1358 reflections. R = 0.066. Ba3[Fe(CN)6]2 · 2 C6H12N4 · 11 Η2Ο. monoclinic. space group P21/n, Ζ = 2, a = 1148.0(4), b = 1369.7(4), c = 1584.5(4) pm, γ = 95.79(3)°, 2583 reflections, R = 0.057. The crystal structures of these adducts are compared with those of other hexamethylenetetramine adducts of alkaline and alkaline earth metal hexacyanoferrates of the general formula M,[Fe(CN)6]y · zC6H12N4 · vH2O recently investigated by us. A structural model for the adducts is presented.

Dinuclear uranium(vi) salen coordination compound: an efficient visible-light-active catalyst for selective reduction of CO2 to methanol

2020 ◽  
Vol 49 (47) ◽  
pp. 17243-17251
Author(s):  
Mohammad Azam ◽  
Umesh Kumar ◽  
Joshua O. Olowoyo ◽  
Saud I. Al-Resayes ◽  
Agata Trzesowska-Kruszynska ◽  
...  
Keyword(s):  
Visible Light ◽  
Coordination Compound ◽  
Active Catalyst ◽  
Selective Reduction ◽  
Photocatalytic Reduction ◽  
Visible Light Active ◽  
Reduction Of Co2

The newly synthesized dinuclear uranyl salen coordination compound showed excellent photocatalytic reduction of CO2 to methanol.

Darstellung einiger Alkali- und Erdalkaliperoxoborate durch Perhydrolyse von Tris(methoxy)boran / Preparation of Some Peroxoborates of Alkaline and Alkaline Earth Metals by Perhydrolysis of Tris(methoxy)borane

1977 ◽  
Vol 32 (12) ◽  
pp. 1393-1399 ◽  
Author(s):  
Gert Heller ◽  
Jürgen Zambelli
Keyword(s):  
Ir Spectra ◽  
Boric Acid ◽  
Raman Spectra ◽  
Alkaline Earth ◽  
Structural Features ◽  
Chain Structure ◽  
Alkaline Earth Metals ◽  
Experimental Conditions ◽  
Molar Ratios ◽  
A Chain

Perhydrolysis of the trimethyl ester of boric acid with Η2O2/Η2Ο (85:15 by weight) in butanolic solvents in the presence of lithium- or cesium-tert-butylate in certain molar ratios yields Li2[B2(O2)2(OH)4 or Cs2[B2(O2)2(OH)4].In methanol in the presence of MX2, where M = Ca, Sr or Ba and X = N-methylacetamide depending on the experimental conditions M[B2(O2)2(OH)4] · n CH3OH, M[B2(O2)2(OH)2(OOH)2] · CH3OH or a compound with a chain structure (anion C) are obtained. Perhydrolysis with H2O2/ H2O (98:2 by weight) yields Sr[B2(O2)2(OOH)4] · CH3OH, Ba[B2(O2)2(OOH)4] · CH3OH or Ba[B2(O2)2(OOH)4] · 2 H2O2.Based on IR spectra and Raman spectra the structural features of these salts are discussed.

Selective reduction of nitroaromatics to azoxy compounds on supported Ag–Cu alloy nanoparticles through visible light irradiation

2016 ◽  
Vol 18 (3) ◽  
pp. 817-825 ◽  
Author(s):  
Zhe Liu ◽  
Yiming Huang ◽  
Qi Xiao ◽  
Huaiyong Zhu
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Selective Reduction ◽  
Photocatalytic Reduction ◽  
Light Irradiation ◽  
Azo Compounds ◽  
Alloy Nanoparticles ◽  
Ag Nps ◽  
Azoxy Compounds ◽  
Cu Alloy

The photocatalytic reduction of nitroaromatics on Ag–Cu alloy NPs can maintain the selectivity to azoxy compounds, whereas Ag NPs mainly obtain azo compounds.

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