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1.
Samarium and nitrogen co‐doped Bi 2WO 6 nanosheets were successfully synthesized by using a hydrothermal method. The crystal structures, morphology, elemental compositions, and optical properties of the prepared samples were investigated. The incorporation of samarium and nitrogen ions into Bi 2WO 6 was proved by X‐ray diffraction, energy dispersive X‐ray spectroscopy, and X‐ray photoelectron spectroscopy. UV/Vis diffuse reflectance spectroscopy indicated that the samarium and nitrogen co‐doped Bi 2WO 6 possessed strong visible‐light absorption. Remarkably, the samarium and nitrogen co‐doped Bi 2WO 6 exhibited higher photocatalytic activity than single‐doped and pure Bi 2WO 6 under visible‐light irradiation. Radical trapping experiments indicated that holes (h +) and superoxide radicals ( . O 2?) were the main active species. The results of photoluminescence spectroscopy and photocurrent measurements demonstrated that the recombination rate of the photogenerated electrons and holes pairs was greatly depressed. The enhanced activity was attributed to the synergistic effect of the in‐built Sm 3+/Sm 2+ redox pair centers and the N‐doped level. The mechanism of the excellent photocatalytic activity of Sm‐N‐Bi 2WO 6 is also discussed. 相似文献
2.
In this study, the characterization and photocatalytic activity of Bi 2WO 6/Bi 2O 3 under visible‐light irradiation was investigated in detail. The results suggested that Bi 2WO 6/Bi 2O 3 can be synthesized by a facile one‐pot hydrothermal route using a super big 200 mL Teflon‐lined autoclave with optimal sodium oleate/Bi molar ratio of 1.25. Through the characterization of Bi 2WO 6/Bi 2O 3 by X‐ray diffraction, scanning electron microscopy, X‐ray photoelectron spectroscopy, Fourier transform infrared, UV‐vis diffuse reflectance spectra and Photoluminescence spectra, it was found that the as‐prepared composite possessed smaller crystallite size and higher visible‐light responsive than the pure Bi 2WO 6. Moreover, it was expected that the as‐prepared composites exhibited enhanced photocatalytic activity for the degradation of Rhodamine B under visible‐light irradiation, which could be ascribed to their improved light absorption property and the reduced recombination of the photogenerated electrons and holes during the photocatalytic reaction. In general, this study could provide a principle method to synthesize Bi 2WO 6/Bi 2O 3 with enhanced photocatalytic activity by one‐step hydrothermal synthesis route for environmental purification. 相似文献
3.
Bi2WO6/UiO-66-NH2 photocatalysts were fabricated through solvothermal method using acetic acid as template. The photocatalytic performance of as-fabricated composites was highly improved under simulated visible light due to the addition of UiO-66-NH2. The structural and chemical properties of the composites were characterized through FTIR, XRD, XPS, SEM, BET, UV–vis DRS and PL. After 90 min of visible light irradiation, the RhB at an initial concentration of 10 mg·L?1 in the solution was degraded by 99.4% due to the addition of 10 mg of the composite. There was no significant decrease in the photocatalytic activity even after four rounds of cycles. The free radical capture experiments indicate that the photogenerated holes (h+) were the main active sites. The possible photocatalytic degradation mechanism was proposed as the specific surface area of the composite was enlarged due to the uniform distribution of UiO-66-NH2 on the surface of Bi2WO6. The electron–hole pairs recombination rate was decreased due to the photogenerated electrons (e?) on the CB of Bi2WO6 which can be rapidly transferred to the CB of UiO-66-NH2 and the photogenerated holes of UiO-66-NH2 transferred to the VB of Bi2WO6. Meanwhile, the RhB was directly oxidized to H2O and CO2 by h+ to achieve the purification effect. 相似文献
4.
The photocatalytic ability of ZnO is improved through the addition of flower-like Bi 2WO 6 to prepare a Bi 2WO 6/ZnO composite with visible light activity. The composite is characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy with UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy and N 2 adsorption-desorption isotherms. After modification, the band gap energy of Bi 2WO 6/ZnO is reduced from 3.2 eV for ZnO to 2.6 eV. Under visible light irradiation, the Bi 2WO 6/ZnO composite shows an excellent photocatalytic activity for degrading methylene blue (MB) and tetracycline. The photo-degradation efficiencies of (0.3:1) Bi 2WO 6/ZnO for MB and tetracycline are approximately 246 and 4500 times higher than those of bare ZnO, respectively, and correspondingly, the photo-degradation rates for the two pollutants are approximately 120 and 200 times higher than those with bare ZnO, respectively. Moreover, the photocatalyst of (0.3:1) Bi 2WO 6/ZnO exhibits a higher transient photocurrent density of approximately 4.5 μA compared with those of bare Bi 2WO 6 and ZnO nanoparticles. The successful recombination of Bi 2WO 6 and ZnO enhances the photocatalytic activity and reduces the band gap energy of ZnO, which can be attributed to the effective separation of electron–hole pairs. Active species trapping experiments display that [O 2] ? is the major species involved during photocatalysis rather than ?OH and h +. This study provides insight into designing a meaningful visible-light-driven photocatalyst for environmental remediation. 相似文献
5.
CeO 2/Bi 2WO 6 heterostructured microsphere with excellent and stable photocatalytic activity for degradation tetracyclines was successfully synthesized via a facile solvothermal route. The photocatalytic experiments indicated that CeO 2/Bi 2WO 6 heterostructured microspheres exhibited enhanced photocatalytic activity compared to pure Bi 2WO 6 in both the degradation of tetracycline hydrochloride (TCH) and rhodamine B (RhB) under visible‐light irradiation. The 1CeO 2/2Bi 2WO 6 exhibited the best photocatalytic activity for degradation of TCH, reaching 91% after 60 min reaction. The results suggested that the particular morphological conformation of the microspheres resulted in smaller size and more uniform morphology so as to increase the specific surface area. Meanwhile, the heterojunction was formed by coupling CeO 2 and Bi 2WO 6 in the as‐prepared microspheres, so that the separation efficiency of photogenerated electrons and holes was dramatically improved and the lifetimes of charge carriers were prolonged. Hence, introduction of CeO 2 could significantly enhance the photocatalytic activity of CeO 2/Bi 2WO 6 heterostructured microspheres and facilitate the degradation of TCH. This work provided not only a principle method to synthesize CeO 2/Bi 2WO 6 with the excellent photocatalytic performance for actual produce, but also a excellent property of the photocatalyst for potential application in photocatalytic treatment of tetracyclines wastewater from pharmaceutical factory. 相似文献
6.
采用简单的沉积方法制备了不同碘化氧铋含量的BiOI/Bi 2WO 6光催化剂,通过X射线衍射(XRD)、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HR-TEM)、紫外-可见漫反射光谱(UV-VisDRS)和BET比表面积测量对其进行了表征。在紫外和可见光的照射下,使用甲基橙和苯酚的光催化降解评价了BiOI/Bi 2WO 6催化剂的光催化性能。结果表明:与商业P 25和纯Bi 2WO 6相比,13.2%BiOI/Bi 2WO 6光催化剂具有更高的紫外和可见光催化性能。这明显增加的光催化活性主要归功于光生电子和空穴在Bi 2WO 6和BiOI界面上的有效转移,降低了电子-空穴对的复合。基于BiOI和Bi 2WO 6的能带结构,提出了光生载流子的一种转移过程。自由基清除剂的实验表明,OH,h +,O 2和H 2O 2,特别是h +,共同支配了甲基橙和苯酚的光催化降解过程。 相似文献
7.
Visible-light-driven heterostructure Ag/Bi2WO6 nanocomposites were prepared by transforming Ag+ ions into metallic Ag0 nanoparticles loaded on top of Bi2WO6 nanoplates under visible light irradiation for 1 h. XRD, XPS, SEM and TEM analyses indicated that spherical metallic Ag nanoparticles were uniformly dispersed on top of orthorhombic Bi2WO6 thin nanoplates. Rhodamine B (RhB) was used as a dye model for investigation of photocatalytic performance of Bi2WO6 nanoplates with different weight contents of Ag nanoparticles illuminated by visible radiation. In this research, 10% Ag/Bi2WO6 nanocomposites have the highest photocatalytic activity in the degradation of RhB at 94.21% within 210 min because of the rapid diffusion of electronic charge through the Schottky barrier between metallic Ag nanoparticles and Bi2WO6 thin nanoplates, good electrical conductivity of metallic Ag nanoparticles, inhibited recombination of charge carriers and enhanced photocatalytic activity of Ag/Bi2WO6 nanocomposites. Main active species of the photocatalysis and stability of the photocatalyst were also evaluated. 相似文献
8.
Hierarchical Ag/Bi 2WO 6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag from Ag + precursors. In situ energy dispersive X-ray diffraction (EDXRD) monitoring showed that the hydrothermal formation kinetics of Bi 2WO 6 in the presence of EG was significantly slowed down due to its very high viscosity. The photocatalytic activities of Ag/Bi 2WO 6 composites were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation. The photocatalytic activity of Bi 2WO 6 is strongly influenced by the Ag loading. The enhanced catalytic activity of the composites is based on the cooperative effects of plasmon absorption band and separation of photogenerated electron-hole pairs. 相似文献
9.
Bi 2WO 6/TiO 2 heterojunction photocatalysts with two different microstructures were controllably fabricated via a facile two-step synthetic route. XRD, XPS, SEM, TEM, BET-surface, DRS, PL spectra, photoelectrochemical measurement (Mott-Schottky), and zeta-potential analyzer were employed to clarify structural and morphological characteristics of the obtained products. The results showed that Bi 2WO 6 nanoparticles/nanosheets grew on the primary TiO 2 nanorods. The TiO 2 nanorods used as a synthetic template inhibit the growth of Bi 2WO 6 crystals along the c-axis, resulting in Bi 2WO 6/TiO 2 heterostructure with one-dimensional (1D) morphology. The photocatalytic properties of Bi 2WO 6/TiO 2 heterojunction photocatalysts were strongly dependent on their shapes and structures. Compared with bare Bi 2WO 6 and TiO 2, Bi 2WO 6/TiO 2 composite have stronger adsorption ability and better visible light photocatalytic activities towards organic dyes. The Bi 2WO 6/TiO 2 composite prepared in EG solvent with optimal Bi:Ti ratio of 2:12 (S-TB2) showed the highest photocatalytic activity, which could totally decompose Rhodamine B within 10 min upon irradiation with visible light (λ > 422 nm), and retained the high photocatalytic performance after five recycles, confirming its stability and practical usability. The results of PL indicated that Bi 2WO 6 and TiO 2 could combine well to form a heterojunction structure which facilitated electron–hole separation, and lead to the increasing photocatalytic activity. 相似文献
10.
采用简单的沉积方法制备了不同碘化氧铋含量的BiOI/Bi2WO6光催化剂,通过X射线衍射(XRD)、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HR-TEM)、紫外-可见漫反射光谱(UV-Vis DRS)和BET比表面积测量对其进行了表征。在紫外和可见光的照射下,使用甲基橙和苯酚的光催化降解评价了BiOI/Bi2WO6催化剂的光催化性能。结果表明:与商业P25和纯Bi2WO6相比,13.2%BiOI/Bi2WO6光催化剂具有更高的紫外和可见光催化性能。这明显增加的光催化活性主要归功于光生电子和空穴在Bi2WO6和BiOI界面上的有效转移,降低了电子-空穴对的复合。基于BiOI和Bi2WO6的能带结构,提出了光生载流子的一种转移过程。自由基清除剂的实验表明,·OH,h+,·O2-和H2O2,特别是h+,共同支配了甲基橙和苯酚的光催化降解过程。 相似文献
11.
Introducing plasmonic metals into semiconductor materials has been proven to be an attractive strategy for enhancing photocatalytic activity in the visible region. In this work, a novel and efficient Ag/Ag 2WO 4/g‐C 3N 4 (AACN) ternary plasmonic photocatalyst was successfully synthesized using a facile one‐step in situ hydrothermal method. The composition, structure, morphology and optical absorption properties of AACN were investigated using X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and UV–visible diffuse reflectance spectroscopy, respectively. Photocatalytic performance of AACN was evaluated via rhodamine B and tetracycline degradation. The results indicated that AACN had excellent photocatalytic performance for rhodamine B degradation with a rate constant of 0.0125 min ?1, which was higher than those of Ag 2WO 4 and Ag/Ag 2WO 4. Characterization and photocatalytic tests showed that the strong coupling effect between the Ag/Ag 2WO 4 nanoparticles and the exfoliated ultrathin g‐C 3N 4 nanosheets was superior for visible‐light responsivity and reduced the recombination rate of photogenerated electrons and holes. A proposed mechanism is also discussed according to the band energy structure and the experimental results. 相似文献
12.
TiO 2/Bi 2WO 6 composite nanofibers have been successfully synthesized by a simple electrospinning process. XRD, SEM, HR-TEM, nitrogen adsorption–desorption isotherms and UV–visible diffuse reflectance spectra were used to characterize the composite nanofibers. The composite fibers with diameters about 100 nm was composed of nanoparticles and possessed of high specific surface area (49.6 m 2 g ?1) and porous structure. Besides, the TiO 2/Bi 2WO 6 composite nanofibers exhibited excellent visible photocatalytic property in the photodegradation of methylene blue (MB), and over 97.2 % of MB was degraded within 5.5 h. 相似文献
13.
The Bi 2O 3/Bi 2WO 6 heterojunction photocatalysts were prepared by a two-step solvothermal process using Bi(NO 3) 3-ethylene glycol solution as Bi source. The catalysts were characterized by X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis diffuse reflection spectroscopy. The heterostructure catalysts are composed of Bi 2O 3 nanoparticles as modifier and 3D Bi 2WO 6 microspheres as substrate. Bi 2O 3 nanoparticles with diameters of about 10-15 nm are tightly grown on the lateral surface of the Bi 2WO 6 microspheres. The hierarchical Bi 2O 3/Bi 2WO 6 microspheres exhibit higher photocatalytic activity than the single phase Bi 2WO 6 or Bi 2O 3 for the degradation of rhodamine B under visible light illumination ( λ>420 nm). The enhancement of the photocatalytic activity of the Bi 2O 3/Bi 2WO 6 heterojunction catalysts can be ascribed to their improved light absorption property and the reduced recombination of the photoexcited electrons and holes during the photocatalytic reaction. The effect of loading amount of Bi 2O 3 on the catalytic performance of the heterojunction catalysts was also investigated and the optimal content of Bi 2O 3 is 3 wt%. The Bi 2O 3/Bi 2WO 6 heterojunction photocatalysts are essentially stable during the photocatalytic process. 相似文献
14.
Pd nanoparticles supported on Bi2WO6 nanoplates used for visible-light-driven photocatalyst were successfully synthesized by photoreduction deposition method under visible-light irradiation. Different analytical techniques including X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and photoluminescence spectroscopy revealed that face-centered cubic metallic Pd nanoparticles were uniformly loaded on top of orthorhombic Bi2WO6 nanoplates to form heterostructure Pd/Bi2WO6 nanocomposites. Photocatalytic activities of pure Bi2WO6 sample and heterostructure Pd/Bi2WO6 nanocomposites were studied through the photodegradation of rhodamine B (RhB) under visible-light irradiation. The photocatalytic efficiency of Bi2WO6 was increased to the highest by being loaded with 5 wt% Pd and then decreased by being loaded with 10 wt% Pd. The improved photocatalytic efficiency caused by high-efficiency diffusion and separation of photo-generated charge carriers was explained and can lead to superior photodegradation of RhB under visible-light irradiation. 相似文献
15.
Novel Bi 2WO 6‐coupled Fe 3O 4 magnetic photocatalysts with excellent and stable photocatalytic activity for degrading tetracycline hydrochloride and RhB were successfully synthesized via a facile solvothermal route. Through the characterization of the as‐prepared magnetic photocatalysts by X‐ray diffractometry, scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, UV–Vis diffuse reflectance spectra, it was found that the as‐prepared magnetic photocatalysts were synthesized by the coupling of Bi 2WO 6 and Fe 3O 4, and introduction of appropriated Fe 3O 4 can improve nanospheres morphology and visible‐light response. Among them, BFe2 (0.16% Fe 3O 4) exhibited the best photocatalytic activity for degradation of tetracycline hydrochloride (TCH), reaching 81.53% after 90 min. Meanwhile, the as‐prepared magnetic photocatalysts showed great separation and recycle property. Moreover, the results of electrochemical impedance spectroscopy demonstrated that the well conductivity of Fe 3O 4 can promote photogenerated charge carriers transfer and inhibit recombination of electron–hole pairs, so that Bi 2WO 6/Fe 3O 4 exhibited enhanced photocatalytic activity on degradation of TCH and RhB. Hence, this work provides a principle method to synthesize Bi 2WO 6/Fe 3O 4 with excellent photocatalytic performance for actual application, in addition, it showed that introduction of Fe 3O 4 not only can provide magnetism, but also can enhance photocatalytic activity of Bi 2WO 6/Fe 3O 4 magnetic photocatalysts. 相似文献
16.
One‐dimensional (1D) CeO 2/Bi 2WO 6 heterostructured nanofibers with a diameter of about 300 nm were successfully synthesized by using a straightforward strategy combining an electrospinning technique with a sintering process. The acquired products were characterized by thermogravimetric and differential scanning calorimetric (TG‐DSC), Fourier transform infrared (FT‐IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) surface area measurements, and UV/Vis spectroscopy. The obtained CeO 2/Bi 2WO 6 heterostructured nanofibers exhibited an excellent photocatalytic property for the degradation of Rhodamine B (RhB) dye driven by visible light due to the promoted separation of photoelectrons and holes and the large contact area between the photocatalyst and organic pollutant. 相似文献
17.
One-dimensional Bi 2WO 6 nanofibers have been successfully synthesized by simple electrospinning processes. XRD, SEM and UV–visible diffuse reflectance spectra were used to characterize the nanofibers. The results indicated that the Bi 2WO 6 was composed of one-dimensional nanofibers, whose diameter was about 50 nm. Besides, the Bi 2WO 6 nanofibers exhibited excellent visible photocatalytic property in the photodegradation of methylene blue. 相似文献
18.
The reduced graphene oxide‐Bi 2WO 6 (rGO‐BWO) photocatalysts with the different R F/O values (molar ratio of the F molar mass and the O's molar mass of Bi 2WO 6) had been successfully synthesized via one‐step hydrothermal method. The F‐doped rGO‐BWO samples were characterized by X‐ray diffraction patterns (XRD), field‐emission scanning electron microscopy (FE‐ESEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller surface area (BET), X‐ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectra (DRS). The results indicate that F ? ions had been successfully doped into rGO‐BWO samples. With the increasing of the R F/O values from 0 to 2%, the evident change of the morphology and the absorption edges of F‐doped rGO‐BWO samples and the photocatalytic activities had been enhanced. Moreover, the photocatalytic activity of F‐doped rGO‐BWO with R F/O = 0.05 were better than rGO‐BWO and the other F‐doped rGO‐BWO under 500 W Xe lamp light irradiation. The enhanced photocatalytic activity can be attributed to the morphology of the intact microsphere that signify the bigger specific surface area for providing more possible reaction sites for the adsorption–desorption equilibrium of photocatalytic reaction, the introduction of F ? ions that may cause the enhancement of surface acidity and creation of oxygen vacancies under visible light irradiation, the narrower band gap which means needing less energy for the electron hole pair transition. 相似文献
19.
A novel visible light-responsive homogeneous catalyst based on Bi 2WO 6 quantum dots (QDs-BWO)/Bi 2WO 6 nanosheets (N-BWO) was successfully fabricated through a simple hydrothermal method. A variety of techniques were employed to investigate the morphology, structure, and electronic properties of the samples. The photocatalytic performance of the QDs/N-BWO materials was investigated by monitoring the degradation of 4-chlorophenol and rhodamine B under visible light irradiation. The as-fabricated QDs/N-BWO materials showed higher photocatalytic activity than both QDs-BWO and N-BWO. The results reveal that the incorporation of the QDs improved the separation efficiency of electron-hole pairs, leading to enhanced photocatalytic activity. Moreover, the results of quenching experiments show that ·O 2– species played a major role in the degradation process. This work provides an important reference for the fabrication of homogeneous catalysts with high performance in the degradation of different types of pollutants. 相似文献
20.
Uniform Bi 2WO 6 spheres with high visible light activity were prepared via a solvothermal route. A variety of techniques including transmission electron micrographs (TEM), X-ray powder diffraction (XRD), N 2 adsorption, FT-IR spectra, and UV–Vis spectra were employed to characterize the structure of the Bi 2WO 6 materials so obtained. The results show that the sphere-like Bi 2WO 6 samples were successfully prepared. And, under the photocatalytic degradation of Rhodamine B, the samples demonstrated high activity, three times higher than that of a sample from the solid-state method. Moreover, the uniform structure made the sample easy to separate from the reaction solution, providing an intrinsic advantage to the normal Bi 2WO 6 samples. 相似文献
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