The synthesis and characterization of germanium oxide aerogel

Chen, Geng; Chen, Bo-Wei; Liu, Tianshi; Yang, Mei; Ren, Hao; Bi, Yutie; Zhang, Lin

doi:10.1016/j.jnoncrysol.2012.08.028

Cited by 12 publications

(10 citation statements)

References 30 publications

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“…Germanium compounds are important materials whose preparation mostly starts from germanium(IV) chloride − or when slow, controlled hydrolysis is desirable from germanium alkoxides. − Alkoxides are expensive and generate a waste stream that should be recycled. The solubility of amorphous and hexagonal germanium oxide (0.43 g in 100 g of H 2 O at 20 °C) is higher than that of the tetragonal germania and it is also much higher than the solubility of other post transition metal oxides .…”

Section: Introductionmentioning

confidence: 99%

Crystalline Ammonium Peroxogermanate as a Waste-Free, Fully Recyclable Versatile Precursor for Germanium Compounds

et al. 2019

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High, nearly 100%, yield synthesis of ammonium peroxogermanate (APG), (NH 4 ) 6 [Ge 6 (μ-OO) 6 (μ-O) 6 -(OH) 6 ]•6H 2 O, is presented, and its crystal structure is determined by single crystal X-ray study. It comprises centrosymmetric hexanuclear peroxogermanate anions [Ge 6 -(μ-OO) 6 (μ-O) 6 (OH) 6 ] 6− with six μ-oxoand six μ-peroxo groups forming negatively charged layers. The space between these layers is filled by ammonium cations and water molecules, forming a highly stable structure due to hydrogen bonding. Highly soluble macroporous amorphous germanium oxide (HSGO) is then synthesized by mild treatment of APG. The compound forms highly oversaturated metastable germanium oxide solution with a solubility of 100 g/L, over 20 times higher than the solubility of amorphous germanium oxide. HSGO solution is a versatile reagent that can react with basic and acidic reagents to give a diverse range of salts including, e.g., germanium sulfide, germanium hydrophosphate, and potassium germanate. In the absence of acid or base, the aqueous HSGO solution yields hexagonal germanium oxide under ambient conditions.

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Section: Introductionmentioning

confidence: 99%

Crystalline Ammonium Peroxogermanate as a Waste-Free, Fully Recyclable Versatile Precursor for Germanium Compounds

et al. 2019

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“…Germanium dioxide, GeO 2 , has a band gap of 5 eV, higher than other transparent conductive oxides, thus making this material suitable for the development of luminescent devices operating from the ultraviolet to the near-infrared range . GeO 2 has also been used in catalysis and infrared optics due to its high linear coefficient of thermal expansion. , Highly mesoporous aerogels of pure GeO 2 have also been prepared that show high thermal stability . However, probably the most attractive property of GeO 2 is its refractive index, which at 1.7 is greater than for SiO 2 (1.455) and makes germania an ideal candidate for optical fibers , either alone or as a composite with SiO 2 .…”

Section: Geo2mentioning

confidence: 99%

“…This high solubility of germania strictly limits its synthesis and application in aqueous media, and is one of the main reasons why the synthesis of GeO 2 (from germanium alkoxide) is often performed in a mixture of water and alcohol. ,,, The alcohol fraction facilitates the miscibility of the precursor in the aqueous media and reduces the solubility of the formed GeO 2 , while water is still available for hydrolysis of the precursor. As an exception, tetragonal GeO 2 can be synthesized in aqueous media even at low concentrations as it is insoluble in water .…”

Section: Geo2mentioning

confidence: 99%

“…605,606 Highly mesoporous aerogels of pure GeO 2 have also been prepared that show high thermal stability. 607 However, probably the most attractive property of GeO 2 is its refractive index, which at 1.7 is greater than for SiO 2 (1.455) 608 and makes germania an ideal candidate for optical fibers 609,610 either alone or as a composite with SiO 2 . 611 The intrinsic properties of Ge and GeO 2 have permitted its use in optoelectronics, biological imaging, and lithium ion batteries as reviewed by Vaughn and Schaak.…”

Section: Toxicology Of Znomentioning

confidence: 99%

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Interactions between Metal Oxides and Biomolecules: from Fundamental Understanding to Applications

et al. 2018

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Metallo-oxide (MO)-based bioinorganic nanocomposites promise unique structures, physicochemical properties, and novel biochemical functionalities, and within the past decade, investment in research on materials such as ZnO, TiO 2 , SiO 2 , and GeO 2 has significantly increased. Besides traditional approaches, the synthesis, shaping, structural patterning, and postprocessing chemical functionalization of the materials surface is inspired by strategies which mimic processes in nature. Would such materials deliver new technologies? Answering this question requires the merging of historical knowledge and current research from different fields of science. Practically, we need an effective defragmentation of the research area. From our perspective, the superficial accounting of material properties, chemistry of the surfaces, and the behavior of biomolecules next to such surfaces is a problem. This is particularly of concern when we wish to bridge between technologies in vitro and biotechnologies in vivo. Further, besides the potential practical technological efficiency and advantages such materials might exhibit, we have to consider the wider long-term implications of material stability and toxicity. In this contribution, we present a critical review of recent advances in the chemistry and engineering of MO-based biocomposites, highlighting the role of interactions at the interface and the techniques by which these can be studied. At the end of the article, we outline the challenges which hamper progress in research and extrapolate to developing and promising directions including additive manufacturing and synthetic biology that could benefit from molecular level understanding of interactions occurring between inanimate (abiotic) and living (biotic) materials.

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“…In the last few years, a significant progress has been reported on the synthesis of GeO 2 materials (Adachi et al, 2005;Zou et al, 2005;Armelao et al, 2012;Chen et al, 2012;Seng et al, 2013;Zhang et al, 2013). Especially, small particles show interesting features such as photoluminescence under visible light irradiation, high refractive index as compared to that of silica glasses and optical transparency in between 280 and 5000 nm (Kim et al, 2007;Chiu and Huang, 2009;Liu et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Synthesis of germanium dioxide nanoparticles in benzyl alcohols – a comparison

Kitschke

Schulze

Hietschold

et al. 2013

Main Group Metal Chemistry

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The surfactant-free synthesis of β-phase germanium dioxide nanoparticles in ortho-methoxy benzyl alcohol and benzyl alcohol has been reported. Characterisation of the hexagonal β-GeO 2 crystals, which involves powder X-ray diffraction, nitrogen adsorption measurements (Brunauer-Emmett-Teller method), dynamic light scattering measurements, IR spectroscopy, transmission electron microscopy and energy-dispersive X-ray analysis has been presented. Synthesis of β-GeO 2 under ambient conditions in benzyl alcohol results in nanoparticles with diameters below 20 nm, whereas the synthesis under inert conditions in benzyl alcohol at reflux (205°C) gives larger nanoparticles. In ortho-methoxy benzyl alcohol, agglomerates with particle sizes above 100 nm are observed under inert atmosphere conditions at room temperature.

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The synthesis and characterization of germanium oxide aerogel

Cited by 12 publications

References 30 publications

Crystalline Ammonium Peroxogermanate as a Waste-Free, Fully Recyclable Versatile Precursor for Germanium Compounds

Crystalline Ammonium Peroxogermanate as a Waste-Free, Fully Recyclable Versatile Precursor for Germanium Compounds

Interactions between Metal Oxides and Biomolecules: from Fundamental Understanding to Applications

Synthesis of germanium dioxide nanoparticles in benzyl alcohols – a comparison

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