Metastable β-Bi₂O₃nanoparticles with high photocatalytic activity from polynuclear bismuth oxido clusters

Abstract

The synthesis of nanoscaled β-Bi(2)O(3) starting from the bismuth oxido clusters [Bi(6)O(4)(OH)(4)](NO(3))(6)·H(2)O, [Bi(22)O(26)(OSiMe(2)(t)Bu)(14)], [Bi(38)O(45)(NO(3))(20)(DMSO)(28)](NO(3))(4)·4DMSO and [Bi(38)O(45)(OMc)(24)(DMSO)(9)]·2DMSO·7H(2)O (OMc = O(2)CC(3)H(5)) under ambient conditions is reported. The metal oxido clusters are regarded as ideal precursors for β-Bi(2)O(3) due to their structural relationship with the latter. Nevertheless, different bismuth oxide polymorphs are accessible dependent on the hydrolysis protocol. Hydrolysis over a period of 18 h gave stable α-Bi(2)O(3) whereas after 3 min an amorphous material is observed. Annealing of the amorphous material at 370 °C gave nanoscaled β-Bi(2)O(3). An unusual high reactivity of the β-Bi(2)O(3) particles with SiO(2) and Al(2)O(3) is observed at temperatures above 400 °C. Powder X-ray diffraction studies, transmission electron microscopy, diffuse reflectance UV/Vis spectroscopy and nitrogen adsorption measurements are used for characterization of the as-prepared β-Bi(2)O(3) nanoparticles. The properties of the β-Bi(2)O(3) nanoparticles depend on the starting bismuth oxido clusters with regard to particle size and optical band gap. The β-Bi(2)O(3) nanoparticles show excellent photocatalytic activity as demonstrated by dye decomposition (rhodamine B, methyl orange, methylene blue and orange G) under visible light.

Nonaqueous Synthesis of a Bismuth Vanadate Photocatalyst By Using Microwave Heating: Photooxidation versus Photosensitized Decomposition in Visible‐Light‐Driven Photocatalysis

“…[12,13] It crystallises in three different polymorphs, az ircon structure with tetragonal symmetry and scheelite structure with either monoclinic or tetragonal symmetry.A mong these, monoclinic scheelite-type BiVO 4 exhibits af avorable visible-light response and activity. [14,15] With af ocuso nc atalyst performance various synthetic routes have been reported for monoclinic BiVO 4 ,w hich include solid-state reaction, [16] hydrothermalp reparation, [17][18][19] sonochemical methods, [20] metal-organic decomposition [21] , and methods based on co-precipitation. [22] In addition, microwave-assisted hydrothermal synthesis was used to prepare nanostructured monoclinic BiVO 4 .…”

“…The conversion of photon energy into chemical energy has become of interest not only for photoinduced water splitting as an environmentally friendly methodt op roduce hydrogen but also forw ater and air purification by the oxidation of pollutants andr eduction of CO 2 . [2,3] In the last few years, diverse Bi-containing visible-light-driven photocatalysts, such as Bi 2 O 3 , [4,5] Bi 2 O 2 CO 3 , [6] BiFeO 3 , [7] Bi 2 WO 6 [8] ,a nd Bi 2 MoO 6 [9] and bismuth titanates Bi 4 Ti 3 O 12 ,B i 12 TiO 20 ,a nd (Bi 2Àx Ti 0.75x )Ti 2 O 7 , [10] have been investigated intensely. [11] BiVO 4 is among the most promising candidates and, in addition to high photocatalytic activity, it offers low toxicitya nd negligible photocorrosion.…”

Enhanced Performance of β-Bi2O3by In-Situ Photo-Conversion to Bi2O3-BiO2-xComposite Photoanode for Solar Water Splitting

“…Bismuth oxide is available in six different polymorphs. 23,24 Among these polymorphs, monoclinic α and face centered cubic δ phases are the stable phases at room temperature and at above 730…”

Synthesis and structural studies of the simplest bismuth(iii) oxo-salicylate complex: [Bi4(μ3-O)2(HO-2-C6H4CO2)8]·2Solv (Solv = MeCN or MeNO2)

“…The chemistry of these oxo clusters has been reviewed. 9,[11][12][13][14][15][16][17] Often when reacting bismuth halides with sodium salts of alkoxides or carboxylates, oxo-compounds are obtained. We discovered that protonolysis of BiPh 3 using acidic organic compounds can avoid the formation of oxo ligands and have applied this methodology to the production of [Bi(OC 6 F 5 ) 3 (toluene)] 2 , Bi(Hsal) 3 and various derivatives thereof.…”