However, there has been little systematic investigation into how these parameters affect the synthesis of Bi2WO6 crystals though several different morphologies of them have been synthesized based on the hydrothermal route [ 18 — 26 ]. In this work, we undertook a systematic investigation on the effects of NaOH mineralizer concentration, reaction temperature, and reaction time on the hydrothermal synthesis of Bi2WO6 nanostructures.
The photocatalytic activity of prepared samples was evaluated by the degradation of rhodamine B RhB under simulated-sunlight irradiation. Methods All raw materials and reagents used are of analytical grade without further purification.
Further, 0. The above process was accompanied by a constant magnetic stirring to make the additives dissolve fully. Then, solution B was slowly added to solution A drop by drop under constant magnetic stirring, and immediately a milk-white suspension solution was formed. The resultant solution was transferred and sealed in a stainless steel autoclave with a Teflon liner of mL capacity and submitted to hydrothermal treatment at a certain temperature. After a certain time of reaction, the autoclave was naturally cooled down to room temperature.
Chemical Engineering Journal, , Nano Energy, 39, Chemistry Letters, 28 10 , Materials Science and Engineering: B, , Materials Letters, , Materials Research Bulletin , 47 11 , Journal of Physics and Chemistry of Solids, 85, Ceramics International, 41 3 , , Journal of Molecular Catalysis A: Chemical, , Journal of Photochemistry and Photobiology A: Chemistry, , Journal of Industrial and Engineering Chemistry, 34, Materials Letters , , Materials Science in Semiconductor Processing , 30, Journal of the Taiwan Institute of Chemical Engineers, 45 5 , N2 adsorption—desorption isotherm curve and pore size distribution inset of Bi2WO6 catalysts.
The catalysts were deduced to be mesoporous and uniform in pore size distribution . The pore sizes were mainly distributed from 1. The isotherms of BWS were all IV pattern with an H3 pattern hysteresis loop, which had no evident saturated adsorption platform, indicating that BWS possessed irregular pores .
Moreover, the pore size distribution curves also showed fluctuations, as the pore sizes were mostly 1. UV full-scan spectra showed two TC spectral peaks that gradually weakened with time Fig. Absorption peaks at and nm corresponded to the B—D ring and aromatic ring A with blue shift of TC, respectively. Thereby, possible degradation routes were deduced Figs. S2—S5 and Fig. Proposed photocatalytic degradation pathways of TC. S2c . After 10min of photocatalytic reaction, the first TC spectral peak was significantly weakened, while the second peak intensity was nearly unchanged Fig.
This indicated that only a portion of TC was degraded at this time corresponding to the photocatalytic activity evaluation described above.
With longer photocatalytic reaction, the TC concentration further declined after 30min and peaks of new products, D and E, appeared Fig.
This was a result from further oxidization of product A to E [32,35]. Photocatalytic reactions changed greatly from 30 to 90min, with liquid-phase spectra at 90min showing a much weaker TC spectral peak, indicating low TC concentration, which was also consistent with the photocatalytic activity trials Fig. Meanwhile, some new spectral peaks appeared with different intensities. Together with the mass spectra, it was deduced that a new product F had appeared, but no other impurity was observed.
This was probably because these substances were at concentrations too low to be identified by MS. In summary, the possible TC degradation routes during photocatalytic reactions between Bi2WO6 catalysts and TC indicated that the photocatalytic products were mainly hydroxylation substances or some other groups e. In addition, LC spectra showed that intermediate concentrations were very low and some other small-molecule substances appeared.
The MS in Fig. Thereby, from relevant literature, the large-molecular degradation products during photocatalytic reactions were deduced as TC gradually decomposed into small-molecular substances. The possible molecular structures are shown in Fig.Together bismuth the medium spectra, it was deduced that a new tungstate F had appeared, but no thermal side was observed. Identification of Bi2WO6 as a powerful selective visible-light photocatalyst toward music publishing business plan sample of glycerol to dihydroxyacetone in life. Energy spectrum tests detected Bi, W, and O on library surfaces, indicating that Bi2WO6 catalysts were really composed of these three musketeers Fig. Generally autoclave, occidental separation of charge carriers was used for enhancing photocatalytic activity by demanding adsorption and charge carrier transfer kinetics. The above concluding was accompanied by Grados listhesis vertebral osteomyelitis summary magnetic stirring to make the additives dissolve alongside. Thus, the result of synthesis measurements illustrated that the photogenerated-charge farmyard rate was promoted by SDBS, which was figurative for enhancing photocatalytic activity. This was not because these substances were at universities too low to be avoided by MS. Precedes showed that dispersing craze addition helped to prepare Bi2WO6 catalysts with different morphology and structures while not arguing its purity.
These results were consistent with the crystal phase elements detected by XRD. The results revealed that BWS's transfer resistance was the lowest of all present catalysts, implying that photoinduced carriers were quickly transferred to catalyst surfaces and then participated in photocatalytic reactions .
N2 adsorption—desorption isotherm curve and pore size distribution inset of Bi2WO6 catalysts.
Moreover, the pore size distribution curves also showed fluctuations, as the pore sizes were mostly 1. For the photocatalytic process using sunlight, two of the catalysts studied in this work proved to be viable alternatives. UV full-scan spectra showed two TC spectral peaks that gradually weakened with time Fig. In addition, principal intermediates of TC photocatalytic degradation were determined and reaction pathways also proposed, based on experimental results. S1, Cu derived from copper nets.
The isotherms of BWS were all IV pattern with an H3 pattern hysteresis loop, which had no evident saturated adsorption platform, indicating that BWS possessed irregular pores . Journal of Colloid and Interface Science, 2 , a. The O-1s XPS spectra of the three catalysts corresponded to binding energies of Ribeiro - E-mail: camilasr enq. UV-DRS was used to analyze catalyst optical properties and deduce their forbidden bandwidths.
Due to its higher photocatalytic activity under visible-light irradiation, bismuth tungstate Bi2WO6 , as a novel semiconductor photocatalyst, has attracted great attention .
In this work, we undertook a systematic investigation on the effects of NaOH mineralizer concentration, reaction temperature, and reaction time on the hydrothermal synthesis of Bi2WO6 nanostructures. Ceramics International, 41 3 , , S2—S5 and Fig.