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1.
Bi 2WO 6 powder photocatalyst was prepared using Bi(NO 3) 3 and Na 2WO 4 as raw materials by a simple hydrothermal method at 150 °C for 24 h, and then calcined at 300, 400, 500, 600 and 700 °C for 2 h, respectively. The as-prepared samples were characterized with UV-visible diffuse reflectance spectra, fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and N 2 adsorption-desorption measurement. The photocatalytic activity of the samples was evaluated using the photocatalytic oxidation of formaldehyde at room temperature under visible light irradiation. It was found that post-treatment temperature obviously influenced the visible-light photocatalytic activity and physical properties of Bi 2WO 6 powders. At 500 °C, Bi 2WO 6 powder photocatalyst showed the highest visible-light photocatalytic activity due to the samples with good crystallization and high BET surface area. 相似文献
2.
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
3.
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
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.
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
6.
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
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.
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
9.
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
10.
In this study, a hydrostable Z-scheme Ag/CsPbBr 3/Bi 2WO 6 photocatalyst was designed and fabricated for the degradation of Rhodamine B (RhB). The structural instability of CsPbX 3 perovskites in water is one of the main obstacles that restrict their practical application in photocatalytic wastewater treatment. The photocatalyst was prepared in three steps: passivation of CsPbBr 3 nanocrystals (NCs) with 3-mercaptopropionic acid (MPA), construction of a heterojunction between MPA-passivated CsPbBr 3 NCs and Bi 2WO 6 ultrathin nanosheets, and doping Ag nanoparticles as charge mediators in the heterojunction. The as-obtained 5%Ag/20%CsPbBr 3/Bi 2WO 6 exhibits good stability and excellent photocatalytic activity. The degradation rate is 93.9% in 120 min, which is 4.41 times than that of Bi 2WO 6. 相似文献
11.
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
12.
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
13.
以五水合硝酸铋和二水合钨酸钠为原料,以十六烷基三甲基溴化铵(CTAB)为溴源,制备Br掺杂Bi 2WO 6,通过调节CTAB的含量,利用水热法制备了Br掺杂量不同的Bi 2WO 6催化剂。以抗生素环丙沙星、诺氟沙星作为污染物,测试Br掺杂Bi 2WO 6催化剂的光催化性能。结果表明,2%掺杂量(物质的量分数)的Bi 2WO 6相比于Bi 2WO 6的光催化降解性能最好。此外,通过X射线粉末衍射、红外光谱、扫描电镜、荧光光谱、X射线光电子能谱和拉曼光谱等一系列表征,对Br掺杂后催化剂的物相组成、微观形貌、光生电荷分离率和光学性质等进行分析。最后进行了自由基捕获实验并提出了可能的光催化机理。 相似文献
14.
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
15.
以工业固体废弃物粉煤灰漂珠(fly ash cenospheres,FACs)为载体,采用水热法制备了新颖的漂珠负载Bi2WO6复合材料(Bi2WO6/FACs),通过X射线衍射(XRD),扫描电子显微镜(SEM),X-射线光电子能谱(XPS),和紫外-可见漫反射光谱(DRS)技术对其进行了表征。XRD数据显示了正交相Bi2WO6的特征衍射峰。DRS结果证实了引入FACs后Bi2WO6对可见光的吸收增强。在可见光的照射下,以亚甲基蓝溶液的光催化降解评价了Bi2WO6/FACs复合材料的光催化性能。结果表明:Bi2WO6/FACs的光催化性能优于纯Bi2WO6的,其一级反应速率常数(k)为后者的2.4倍。尤其是由于漂珠质轻中空的特性,Bi2WO6/FACS复合光催化剂可长时间漂浮于水面,既能充分吸收光能,又有利于催化剂的回收和重复利用。 相似文献
16.
以工业固体废弃物粉煤灰漂珠(fly ash cenospheres, FACs)为载体, 采用水热法制备了新颖的漂珠负载Bi 2WO 6复合材料(Bi 2WO 6/FACs), 通过X射线衍射(XRD), 扫描电子显微镜(SEM), X-射线光电子能谱(XPS), 和紫外-可见漫反射光谱(DRS)技术对其进行了表征。XRD数据显示了正交相Bi 2WO 6的特征衍射峰。DRS结果证实了引入FACs后Bi 2WO 6对可见光的吸收增强。在可见光的照射下, 以亚甲基蓝溶液的光催化降解评价了Bi 2WO 6/FACs复合材料的光催化性能。结果表明:Bi 2WO 6/FACs的光催化性能优于纯Bi 2WO 6的, 其一级反应速率常数( k)为后者的2.4倍。尤其是由于漂珠质轻中空的特性, Bi 2WO 6/FACS复合光催化剂可长时间漂浮于水面, 既能充分吸收光能, 又有利于催化剂的回收和重复利用。 相似文献
17.
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
18.
通过水热法制备稀土Pr掺杂Bi 2WO 6三维花状微球,利用XRD、SEM、N 2吸附-脱附、紫外-可见吸收光谱和光致发光光谱对所制备的光催化材料进行表征。通过降解亚甲基蓝评价样品的光催化活性。结果表明,1.0% Pr-Bi 2WO 6样品的可见光催化活性最佳,降解率达到95%。Pr掺杂提高了催化剂的可见光吸收性能并且能够束缚光生电子使得电子空穴对有效分离从而获得强氧化物质。对其光催化降解做出了合理的解释。 相似文献
19.
通过水热法制备稀土Pr掺杂Bi 2WO 6三维花状微球,利用XRD、SEM、N 2吸附-脱附、紫外-可见吸收光谱和光致发光光谱对所制备的光催化材料进行表征。通过降解亚甲基蓝评价样品的光催化活性。结果表明,1.0% Pr-Bi 2WO 6样品的可见光催化活性最佳,降解率达到95%。Pr掺杂提高了催化剂的可见光吸收性能并且能够束缚光生电子使得电子空穴对有效分离从而获得强氧化物质。对其光催化降解做出了合理的解释。 相似文献
20.
Ag/Bi 2WO 6 nanocomposites were successfully synthesized by a combination of hydrothermal method and ultrasonic vibration. The phases, vibration modes, constituents and morphologies were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The visible-light-driven photocatalytic activitiy of 0–10 wt% Ag/Bi 2WO 6 samples was studied by determining the photodegradation of rhodamine B under xenon lamp. In this research, 10 wt% Ag/Bi 2WO 6 nanocomposites exhibit the highest efficiency and have the promising photocatalytic properties for waste water treatment. 相似文献
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