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Investigation of structural and compositional changes in silver-doped GeO2 thin films

“…Significant changes in comparison with the IR spectrum of pure GeO 2 are observed in that of GeO 2 -Ag + films heated at 600°C: new absorption bands at 722, 770 and 818 cm À1 appear in the spectrum along with those characteristic of Ge-O-Ge linkage vibrations in hexagonal GeO 2 (the triplet at 508, 548, 580 cm À1 , and the band at 865 cm À1 ). We have already observed such bands in the IR-spectrum of GeO 2 -Ag + xerogel heated at 500°C [14,15]. Since the silver germanate phase of Ag 2 Ge 4 O 9 was present in that sample, as evidenced by the X-ray diffraction data, we assigned those bands to Ge-O-Ag linkage vibrations.…”

“…The possibility of thermostimulated formation of silver nanoparticles in sol-gel silver-doped GeO 2 thin films on air-heating above 600°C has been found in our previous works [14,15]. A systematic investigation into the effects of heating temperature on the processes involved was carried out for silver-doped GeO 2 xerogels, and the reason for silver nanoparticles being formed during airheating was found to be the silver germanate phase being produced at 350-500°C and thermally decomposed on further heating (at 700-800°C) to give tetragonal GeO 2 phase, which is not typical of germanium dioxide at those temperatures in the absence of silver.…”

“…In the films heated at 350-500°C glassy GeO 2 is formed (the bands at 564 and 865 cm À1 ), which crystallizes on heating at 600°C, the bands characteristic of Ge-OGe linkage vibrations in hexagonal GeO 2 being observed in the IR-spectrum (a triplet at 516, 540, 585 cm À1 , and a band at 870 cm À1 ). Note that according to X-ray diffraction and IR absorption data for GeO 2 xerogels [14,15] hexagonal crystalline modification of GeO 2 was formed at the temperature as low as 350°C [14,15].…”

Rational Design of Ag‐Based Catalysts for the Electrochemical CO2 Reduction to CO: A Review

“…It was also reported that structure, morphology, size, and composition of the catalyst can lead to adsorption and decoupling site preferences of different adsorbates of C bound on the surface and further result in the breaking of the linear scaling relationships and tuning of the adsorption strength, eventually exerting a dramatic influence on the ECR performance . Indeed, in addition to polycrystalline and single‐crystalline Ag, some new A types have been developed and characterized recently, such as nanostructured Ag with different sizes, supported Ag catalysts with different substrates including C, TiO 2 , Al 2 O 3 , dopant‐aided Ag, oxide‐derived Ag, and surface‐modified Ag …”

“…Oxide‐derived Ag (OD‐Ag) has the same electronic structure of metallic Ag according to X‐ray diffraction, X‐ray photoelectron spectroscopy, X‐ray absorption near‐edge structure, and other spectroscopic characterizations . OD‐Ag shows both significant advances and promising potentials for the ECR to CO due to its capability to break the unfavorable linear scaling relationships of BEs between the reaction intermediates including .…”