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1.
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
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.
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
4.
Highly efficient visible-light-driven Ag 3PO 4/Bi 2MoO 6 hybrid photocatalysts with different mole ratios of Ag 3PO 4 were prepared via sonochemical method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that product are cubic Ag 3PO 4 nanoparticles supported on orthorhombic Bi 2MoO 6 nanoplates. Under visible light irradiation (>420 nm), the Ag 3PO 4/Bi 2MoO 6 photocatalysts displayed the higher photocatalytic activity than pure Bi 2MoO 6 for the decolorization of rhodamine B (RhB). Among the hybrid photocatalysts, 10% Ag 3PO 4/Bi 2MoO 6 exhibited the highest photocatalytic activity for the decolorization of RhB due to the efficient separation of electron–hole pairs. 相似文献
5.
利用溶剂热法, 把Bi 2WO 6纳米颗粒植入g-C 3N 4层间和表面成功地制备了Bi 2WO 6/g-C 3N 4复合型光催化剂。通过XRD、SEM、TEM、BET和UV-Vis分别对样品的结构、组成、形貌、比表面积、光学性能进行了表征。结果表明, g-C 3N 4层状结构被部分剥离成碎片且与Bi 2WO 6纳米颗粒形成了复合物。Bi 2WO 6/g-C 3N 4复合型光催化剂与单一Bi 2WO 6相比不仅扩展了可见光的响应范围、增大了比表面还加速了光生电子与空穴的分离。结果表明, Bi 2WO 6的最佳负载量为60wt%时, 复合型光催化剂具有最高的可见光催化活性且性能稳定、易回收。 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.
利用水热法合成了Fe3+掺杂的三维分级纳米Bi2WO6,借助X射线衍射(XRD)、场发射扫描电镜(FE-SEM)、透射电镜(HRTEM)、能谱(EDS)、紫外可见漫反射(UV-Vis-DRS)等测试手段对所得样品的相组成、形貌和谱学特征进行了表征。选择罗丹明B为模型污染物研究所得样品在可见光下的催化活性。结果表明,Fe3+掺杂Bi2WO6为新颖的分级纳米结构,且Fe3+掺杂能有效提高Bi2WO6的光催化活性,Fe3+掺杂量对Bi2WO6活性的影响显著;实验结果还表明,所得Fe3+掺杂Bi2WO6催化剂的稳定性较好,易于回收。此外,还对Fe3+掺杂Bi2WO6的光催化活性增强机理进行了研究,缺电子的Fe3+作为电子捕获中心有利于促进光生电子-空穴对的分离,从而提高Bi2WO6的光催化活性。 相似文献
8.
利用水热法合成了Fe 3+掺杂的三维分级纳米Bi 2WO 6,借助X射线衍射(XRD)、场发射扫描电镜(FE-SEM)、透射电镜(HRTEM)、能谱(EDS)、紫外可见漫反射(UV-Vis-DRS)等测试手段对所得样品的相组成、形貌和谱学特征进行了表征。选择罗丹明B为模型污染物研究所得样品在可见光下的催化活性。结果表明,Fe 3+掺杂Bi 2WO 6为新颖的分级纳米结构,且Fe 3+掺杂能有效提高Bi 2WO 6的光催化活性,Fe 3+掺杂量对Bi 2WO 6活性的影响显著;实验结果还表明,所得Fe 3+掺杂Bi 2WO 6催化剂的稳定性较好,易于回收。此外,还对Fe 3+掺杂Bi 2WO 6的光催化活性增强机理进行了研究,缺电子的Fe 3+作为电子捕获中心有利于促进光生电子-空穴对的分离,从而提高Bi 2WO 6的光催化活性。 相似文献
9.
Magnetically separable Fe 3O 4/AgCl photocatalysts were prepared by a one-pot sequential method. A series of techniques proved the hybrid structure of Fe 3O 4/AgCl composites. Fe 3O 4/AgCl composites had a much higher photocatalytic activity toward Rhodamine B (RhB) degradation than pure AgCl under the simulated solar light irradiation. The existence of metal Ag resulted in high photocatalytic activity of Fe 3O 4/AgCl, which was related with the amount of metallic Ag. The scavenging experiments showed that the degradation reaction most probably was initiated by the photoinduced single-electron transfer, and the generation of superoxide anion (O 2 -· ) played a significant role. The composite photocatalysts could be recycled by applying an external magnetic field, and the reused composites maintained their original photocatalytic activity. Fe 3O 4/AgCl composites were highly efficient, magnetically separable, and recoverable. This proves their potential applications in the photodegradation of organic pollutants. 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.
以TiO 2纳米管为模板,采用多组分自组装结合水热法制备Bi 2WO 6/TiO 2纳米管异质结构复合材料。通过多种技术如X射线衍射(XRD),X射线光电子能谱(XPS),N 2吸附-脱附,扫描电镜(SEM),高分辨透射电镜(HRTEM)和紫外可见漫反射吸收光谱(UV-Vis DRS)考察所制备样品的组成、结构、形貌、光吸收和电子性质。Bi 2WO 6纳米片或纳米粒子分布在TiO 2纳米管上,形成异质结构。随后,通过在紫外、可见和微波辅助光催化模式下降解染料罗丹明B(RhB)来评价复合催化剂的光催化活性。与TiO 2纳米管和Bi 2WO 6相比,Bi 2WO 6/TiO 2-35纳米管在多模式下表现出更优异的光催化活性。与紫外和可见降解模式相比,Bi 2WO 6/TiO 2-35纳米管在微波辅助光催化模式下对RhB的降解效率最高。这种增强的光催化活性源于适量Bi 2WO 6的引入、纳米管独特的形貌特征和降解模式所引起的增强的量子效率。降解过程中的活性物种被证明是h +,·OH和·O 2-自由基。而且,在微波辅助光催化模式下,可产生更多的·OH和·O 2-自由基。 相似文献
12.
经由溶剂热反应、光辅助还原过程制备Bi/Bi VO_4Bi_4V_2O_(11)纳米复合光催化材料。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、高分辨率透射电子显微镜(HRTEM)、X射线光电子能谱(XPS)、紫外-可见漫反射光谱(UV-Vis DRS)、N_2吸附-脱附等温线和光致发光(PL)等手段对该复合物进行表征。实验结果表明当金属Bi与BiVO_4Bi_4V_2O_(11)的质量比值为0.8,可见光照射30 min时,Bi/BiVO_4Bi_4V_2O_(11)复合催化剂对罗丹明B(RhB)的降解率可达95.6%。此外,Bi/BiVO_4Bi_4V_2O_(11)对四环素(TC)的降解也表现出增强的光催化性能。Bi/BiVO_4Bi_4V_2O_(11)复合材料提升的光催化性能可能归因于金属Bi的表面等离子体共振(SPR)效应、拓宽的可见光吸收范围和增大的比表面积。此外,提出了复合光催化剂可能的光催化机理。 相似文献
13.
In this work, an Ag-loaded octahedral Bi 2WO 6 photocatalyst has been successfully prepared by the hydrothermal method and photo deposition method. X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDX), field-emission scanning electron microscopy (FE-SEM) and ultra-violet adsorption spectrum (UV-Vis) were employed for characterization of the composite photocatalyst. Furthermore, two different photocatalysts including the obtained Ag-loaded octahedral Bi 2WO 6 were employed here for photodegradation of model contaminated water of Orange II (OII). Results show that Ag-loaded Bi 2WO 6 photocatalyst exhibits superior photocatalytic properties compared to the undoped Bi 2WO 6. The reasons for improvement in photocatalytic activity of the Ag-loaded octahedral Bi 2WO 6 were also discussed. 相似文献
14.
Photoactive metal–organic frameworks (MOFs) have proven to be a promising porous material in the field of catalysis. Controllable integration of these MOFs with inorganic semiconductor materials may endow new multifunctional hybrid materials with preferable photocatalytic properties. In this research, NH2-MIL-125(Ti) nanoplates modified Bi2WO6 microspheres was prepared via a simple solvothermal method. The photocatalytic behaviors of the acquired catalysts was evaluated via the degradation of tetracycline hydrochloride (TC) under visible light. The experimental results showed that NH2-MIL-125(Ti)/Bi2WO6 composites display higher photocatalytic activity than that of single Bi2WO6, and the ideal incorporation amount of NH2-MIL-125(Ti) was around 5 wt%. The steady state fluorescence spectrum, transient photocurrents and electrochemical impedance spectroscopy verified that the introduction of NH2-MIL-125(Ti) could accelerate the separation and transfer of photogenerated carriers and thus improve the photocatalytic activity of Bi2WO6. The photocatalytic mechanism was explored in detail. This work extends the knowledge of integrating MOFs with traditional photocatalysts to form new composite materials in the area of environmental purification. 相似文献
15.
Solid photocatalysts with high specific surface area,superior photoactivity and ease of recycling are highly desired in chemical process,water treatment and so on.In this study,a facile stepwise sol-gel coating approach was utilized to synthesize Pt decorated oxygen-deficient mesoporous titania microspheres with core-shell structure and convenient magnetic separability(denoted as Fe_3 O_4@-SiO_2@Pt/mTiO_(2-x)).These photocatalysts consist of magnetic Fe_3 O4 cores,nonporous insulating SiO_2 middle layer and mesoporous anatase TiO_(2-x) shell decorated by Pt nanoparticles(~3.5 nm) through wet impregnation and H_2 reduction.As a result of high activity of oxygen-deficiency of black TiO_(2-x) by H_2 reduction and efficient inhibition of electron-hole recombination by Pt nanoparticles,the rationally designed core-shell Fe_3 O_4@SiO_2@Pt/mTiO_(2-x) photocatalysts exhibit superior photocatalytic performance in rhodamine B(RhB) degradation under visible light irradiation,with more than 98% of RhB degraded within 50 min.These core-shell structured photocatalysts show excellent recyclability under the assistance of magnetic separation with well-retained photocatalytic performance even after running five cycles.This stepwise synthesis method paves the way for the rational design of a high-efficiency recyclable heterogeneous catalyst,including photocatalysts,for various applications. 相似文献
16.
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
17.
采用一种简单的无模板水热合成法制备了具有分级结构的钨酸铋纳米花,并将钨酸铋纳米花材料应用于可见光催化去除水中的四环素类抗生素。通过X射线粉末衍射、扫描电镜、透射电镜、紫外固体漫反射、比表面分析等一系列物理表征对光催化剂和催化反应体系进行了表征。研究结果表明钨酸铋纳米光催化剂对四环素类抗生素(四环素和土霉素)均具有良好的降解能力。此外,催化剂对碱性溶液中四环素的降解效率普遍较高,且该催化剂表现出良好的循环稳定性。 相似文献
18.
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
19.
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
20.
In this paper, Bi 2O 3 and rare earth (La, Ce)‐doped Bi 2O 3 visible‐light‐driven photocatalysts were prepared in a Triton X‐100/ n‐hexanol/cyclohexane/water reverse microemulsion. The resulting materials were characterized by X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface area, photoluminescence spectra (PLS) and UV–Vis diffuse reflectance spectroscopy. The XRD patterns of the as‐prepared catalysts calcined at 500°C exhibited only the characteristic peaks of monoclinic α‐Bi 2O 3. PLS analysis implied that the separation efficiency for electron‐hole has been enhanced when Bi 2O 3 was doped with rare earth. UV–Vis diffuse reflectance spectroscopy measurements presented an extension of light absorption into the visible region. The photocatalytic activity of the samples was evaluated by degradation of methyl orange (MO) and 2,4‐dichlorophenol (2,4‐DCP). The results displayed that the photocatalytic activity of rare earth‐doped Bi 2O 3 was higher than that of dopant‐free Bi 2O 3. The optimal dopant amount of La or Ce was 1.0 mol%. And the mechanisms of influence on the photocatalytic activity of the catalysts were discussed. 相似文献
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