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Synthesis of La doped Bi 2 WO 6 nanosheets with high visible light photocatalytic activity
| Content Provider | Semantic Scholar |
|---|---|
| Copyright Year | 2017 |
| Abstract | energy shortage since it is a facile and environmentally friendly way to take advantage of solar energy [1–4]. As is well known, the wide band gap of traditional TiO2 photo catalyst restricts its light absorption to ultraviolet light (λ < 400 nm), which accounts for only about 4% of the whole energy of the incoming solar spectrum [5–8]. Considerable attention has therefore been paid to the development of visible-light-driven semiconductor photo catalysis. Bismuth tungstate (Bi2WO6), as a typically layered Aurivillius oxide, has a relatively narrow band-gap (2.6–2.8 eV), which allows it to absorb visible light. Thus, it shows great potential as a visible-light-driven photo catalyst [9–12]. However, the life of the photo-generated electron–hole pairs is very short, and facile recombination can occur, resulting in low quantum efficiency [13]. In order to resolve these problem, the route of ion doping by incorporation of a certain amount of metal or nonmetal elements into Bi2WO6. Till now, doping by metal or nonmetal elements, such as Fe, Cu, Au, Mo, Pt, N and C into Bi2WO6 [14–20], the photocatalytic activities were all improved. In recent years, the replacement of Bi3+ by rare-earth ions such as Y3+, Er3+, Gd3+ and Ce3+ has been reported to improve the photocatalytic activity of Bi2WO6 [21–24]. In this work, we selected another rare-earth ions La3+ as a dopant of Bi2WO6. The La3+ doped Bi2WO6 photo catalysts were successfully prepared by a facile hydrothermal route. The photocatalytic activities of as-prepared samples were evaluated by decomposition of RhB under visible light. The results indicated that the La3+ doped Bi2WO6 showed a much higher under visible light photocatalytic activity compared to the pure Bi2WO6. Abstract The La3+ doped Bi2WO6 were synthesized via a facile hydrothermal process. Various characterization techniques, such as X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance spectra (UV–Vis DRS), FT-IR, photoluminescence (PL) spectra and N2 adsorption–desorption isotherm analysis, were employed to investigate the as-prepared products. The results indicate that La3+ replacing Bi3+ enters into the Bi2WO6 lattice, producing a degree of Bi2WO6 lattice distortion. It also has an impact on the crystallinity of Bi2WO6 and the band gap was from 2.64 to 2.79 eV. The photocatalytic results show that when the content of La3+ doping becomes 5%, the degradation rate of Rhodamine B (RhB) was above 98% after 25 min irradiation, This enhancement should be ascribed to the slightly increased band gap and the generated defects by La3+ doping, thus resulting in a much lower recombination rate of the photo-induced electrons and holes. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://pdf.xuebalib.com:1262/xuebalib.com.37371.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
