000 03585nlm1a2200361 4500
001 660157
005 20231030041655.0
035 _a(RuTPU)RU\TPU\network\29125
035 _aRU\TPU\network\25575
090 _a660157
100 _a20190429a2018 k y0engy50 ba
101 0 _aeng
102 _aUS
135 _adrnn ---uucaa
181 0 _ai
182 0 _ab
200 1 _aγ-Bi2O3 - To Be or Not To Be? Comparison of the Sillenite γ-Bi2O3 and Isomorphous Sillenite-Type Bi12SiO20
_fM. Weber [et al.]
203 _aText
_celectronic
300 _aTitle screen
330 _aThe “controlled” synthesis of metastable ?-Bi2O3 by solution based approaches was reported several times recently, but the formation of Bi12SiO20 in the presence of trace amounts of silicates renders the results to be questionable. Here, the preparation of the Sillenite ?-Bi2O3 and the Sillenite-type Bi12SiO20 starting from the polynuclear bismuth oxido cluster [Bi38O45(O2CC3H5)24(DMSO)9] is reported. ?-Bi2O3 crystallizes after calcination at 800 °C of the silicate-free hydrolysis product “[Bi38O45(OH)24]” on a silver sheet. Corrosion of the substrate causes contamination with silver, which is not incorporated into the Bi–O lattice, and was removed by treatment with an aqueous KCN-solution. Bi12SiO20 was obtained after hydrothermal treatment of the bismuth oxido cluster in the presence of NaOH in glass vessels or Na2SiO3 in a Teflon-lined reactor vessel followed by calcination at 600 °C. PXRD studies, scanning electron microscopy, nitrogen adsorption measurements, IR- and Raman spectroscopy, diffuse UV–vis spectroscopy, and DSC were used for characterization. The phase transition of ?-Bi2O3 to give a-Bi2O3 occurred slowly in the temperature range of 348–510 °C (?H??a = 6.57 kJ·mol–1). The silver-containing ?-Bi2O3 exhibits slightly increased Raman modes compared to the silver-free sample due to the SERS effect. In the diffuse UV–vis spectrum ?-Bi2O3 exhibits an absorption edge at ? = 485 nm (Eg = 2.76 eV), and the contamination with silver results in an additional absorption edge at ? = 572 nm. Silver-free ?-Bi2O3 exhibits an absorption edge at ? = 460 nm (Eg = 2.83 eV) and Bi12SiO20 at ? = 422 nm (Eg = 3.16 eV). The photocatalytic activity of the compounds was investigated in the decomposition of aqueous rhodamine B under visible light irradiation, showing silver-containing ?-Bi2O3 to be slightly more effective compared to Bi12SiO20 and significantly more effective than the silver-free ?-Bi2O3.
333 _aРежим доступа: по договору с организацией-держателем ресурса
461 _tInorganic Chemistry
463 _tVol. 57, iss. 14
_v[P. 8540-8549]
_d2018
610 1 _aэлектронный ресурс
610 1 _aтруды учёных ТПУ
701 1 _aWeber
_bM.
_gMarcus
701 1 _aRodriguez (Rodriges) Contreras
_bR. D.
_cVenezuelan physicist, doctor of science
_cProfessor of Tomsk Polytechnic University
_f1982-
_gRaul David
_2stltpush
_3(RuTPU)RU\TPU\pers\39942
701 1 _aZahn
_bD.
_gDietrich
701 1 _aMehring
_bM.
_gMichael
712 0 2 _aНациональный исследовательский Томский политехнический университет
_bИсследовательская школа химических и биомедицинских технологий (ИШХБМТ)
_c(2017- )
_h8120
_2stltpush
_3(RuTPU)RU\TPU\col\23537
801 2 _aRU
_b63413507
_c20190429
_gRCR
856 4 _uhttps://doi.org/10.1021/acs.inorgchem.8b01249
942 _cCF