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1.
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
2.
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
3.
Bi 2WO 6 multilayer films have been fabricated successfully by a layer-by-layer (LbL) technique from Bi 2WO 6 nanoplates, which show higher visible-light photoactivity ( λ>420 nm) than that of Bi 2WO 6 nanoplate powders and P25 TiO 2 films. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and UV-visible absorption spectroscopy. Photocatalytic activities of the films were evaluated by the rhodamine B (RhB) decomposition under UV and visible-light irradiation. Thickness and photoactivity of the film can be modified easily by changing the deposition cycles. Bi 2WO 6 films have the spectral selectivity of the photocatalytic degradation of RhB. Under the wavelength greater than 300 nm, the RhB molecules tend to be transformed to rhodamine over Bi 2WO 6 films selectively. However, in the case of shorter wavelength ( λ=254 nm) light irradiation, the RhB molecules can be photodegraded completely. 相似文献
4.
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
5.
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
6.
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
7.
Bi2MoO6 nanoplates modified with intermetallic AgPd nanoparticles synthesized by photoreduction deposition method were used for visible-light-driven photodegradation of rhodamine B. The as-synthesized AgPd/Bi2MoO6 nanocomposites were identified by XRD. The 2θ diffraction angle of the (111) plane of pure metallic cubic Ag at 38.11° of heterostructure 10% Ag/Bi2MoO6 nanocomposites shifted to a higher diffraction angle at 38.17° of heterostructure 10% Ag0.7Pd0.3/Bi2MoO6 nanocomposites. TEM images of the as-synthesized nanocomposites showed good metallic Ag and intermetallic AgPd nanoparticles with particle size of 10–12 nm which were fully supported on top of Bi2MoO6 nanoplates. Bi2MoO6 nanoplates deposited with intermetallic AgPd nanoparticles show significant photocatalytic activity better than Ag/Bi2MoO6 and Bi2MoO6 due to the formation of AgPd/Bi2MoO6 Schottky barrier. 相似文献
8.
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
9.
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
10.
The visible-light-driven photocatalyst Bi 2WO 6 nanoparticles have been prepared by calcining amorphous complex precursor at a relatively low temperature of above 450 oC. The effects of calcination temperature and time on the structures and properties of Bi 2WO 6 nanoparticles have been investigated in detail. The photocatalytic activity of the Bi 2WO 6 powders were evaluated by degradation of RhB molecules in water under visible light irradiation ( λ>400 nm). The results showed that the particle size and grain size of Bi 2WO 6 increased with the calcination temperature and time. The photocatalytic activity of the best sample was about 8.8 times higher than that of the sample prepared by traditional solid state reaction and the photo-degradations was a zero-order reaction. The best route to enhance the photocatalytic activity of Bi 2WO 6 was to prepare the sample at a lower temperature for a longer time, due to the samples with better crystallization and smaller particle size. 相似文献
11.
通过简单水热制备了大小均一,直径约为2.5 μm的球状Bi2WO6粉体.系统研究表面活性剂SDS和PVP对水热制备Bi2WO6光催化剂的影响.利用XRD,EDS,SEM,TEM和DRS等分析技术对催化剂的组成、形貌、比表面积和带隙宽度等进行了表征.实验结果表明,表面活性剂对催化剂的形貌和催化活性有较大影响.在水热制备过... 相似文献
12.
Plasmonic Ag/AgCl‐modified bismuth subcarbonate (Bi 2O 2CO 3) composites were prepared by a multistep process with hydrothermal, deposition, and photoreduction in the absence of organic capping agents. The properties of the obtained Ag/AgCl/Bi 2O 2CO 3 samples were characterized using X‐ray diffraction, field emission scanning electron microscopy and X‐ray photoelectron, UV–visible diffuse reflectance, and photoluminescence spectroscopies. The results reveal that Ag/AgCl nanoparticles are dispersed on the Bi 2O 2CO 3 surface to achieve plasmonic Ag/AgCl/Bi 2O 2CO 3. The Ag/AgCl/Bi 2O 2CO 3 nanocomposites show improved rhodamine B (RhB) adsorption capacity and photocatalytic activity compared with pure Bi 2O 2CO 3 and Ag/AgCl. In addition, the Ag/AgCl/Bi 2O 2CO 3 composite with 20 wt% Ag/AgCl exhibits the highest photocatalytic activity and remains stable for the photodegradation of RhB under visible light. The enhanced photocatalytic activity of Ag/AgCl/Bi 2O 2CO 3 may be attributed to the surface plasmon resonance effect of in situ generated Ag nanoparticles and synergistic effect of Ag/AgCl and Bi 2O 2CO 3, which increase the separation efficiency of photogenerated electron–hole pairs under visible light irradiation. 相似文献
13.
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
14.
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
15.
以硝酸铟作为前驱体,在蒸馏水和乙二胺的混合溶剂中制备出了InOOH纳米晶,详细地考察了反应溶剂及温度对终产物的影响。利用X射线粉末衍射(XRD)、紫外-可见漫反射光谱(UV-Vis DRS)、扫描电子显微镜(SEM)和透射电镜(TEM)对样品的晶相结构、光吸收性质及其形貌进行了详细的表征。考察了样品在紫外光下及可见光下对液相中的染料罗丹明B(RhB)的光催化降解性能。发现InOOH在紫外光下可以彻底分解RhB,而在可见光下只能使RhB脱色。InOOH在紫外光和可见光下对RhB的分解遵循两种不同的反应机制。 相似文献
16.
采用简单的化学还原沉积和二次水热的方法成功制备了CdS和Au共同修饰Z型CdS/Au/Bi2MoO6(CdS/Au/BMO)光催化剂。通过X射线粉末衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)等测试技术对其组成、形貌、光吸收特性和光电化学性能等进行系统表征。实验结果表明,CdS/Au/BMO-2复合材料在可见光照射下表现出最佳的降解效率,其降解RhB的速率常数约为BMO的8.8倍和CdS的20倍。Au NPs作为固态电子媒介,为光生电子的传输和转移提供了一个通道,同时Au NPs的表面等离子体共振(SPR)效应和CdS纳米粒子显著拓宽了催化体系对可见光的响应范围;通过对催化剂的组成、结构和光电性能表征,确定了CdS/Au/BMO的能带结构,进而探讨了CdS/Au/BMO活性增强机制。 相似文献
17.
Ag nanoparticles supported on the surface of three-dimensional (3D) flower-like ZnO nanostructure were synthesized by a microwave-assisted solution method. The obtained products were characterized by X-ray diffraction analysis, field-emission scanning electron microscopy, Fourier-transform infrared spectroscopy, Raman spectrophotometry, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The analytical results confirmed homogeneously distributed Ag nanoparticles supported on the surface of flower-like ZnO nanostructure. The photocatalytic effect of the heterostructure Ag/ZnO nanocomposites was investigated using photodegradation under ultraviolet (UV) light of methylene blue as model dye. The heterostructure Ag/ZnO nanocomposites exhibited much higher photocatalytic activity than pure ZnO flowers. The improved photocatalytic properties are attributed to formation of a Schottky barrier at the metal–semiconductor interface of the Ag/ZnO nanocomposites. 相似文献
18.
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
19.
The novel Bi 2WO 6 nanomaterials, which consist of nanosheets and nanoparticles, were successfully synthesized by a combination of electrospinning
and calcining processes. The Bi 2WO 6 with different morphologies and microstructures had been obtained in the same experimental conditions. The growth mechanism
of such special nanostructures was investigated, and citric acid played an important role in the formation of Bi 2WO 6 nanostructures. The Bi 2WO 6 nanomaterials exhibited excellent photocatalytic property in the photodegradation of the pulping and papermaking wastewater
under visible light irradiation. Besides, preparation of the photocatalyst using electrospinning was beneficial for separation
and recycling. So, the Bi 2WO 6 nanomaterials have a great potential in application for wastewater treatment in the future. 相似文献
20.
通过无模板法一步合成了一种新型N掺杂石墨烯负载的CdS空心球复合材料. 采用X射线衍射、透射电镜、红外光谱、紫外-可见光谱、N 2吸附-脱附、荧光光谱和X射线光电子能谱等技术对该材料进行了表征, 并在可见光照射下测试了其在降解亚甲基蓝和水杨酸中的光催化性能. 结果表明, 相对于氧化石墨烯负载硫化镉空心球和单独的硫化镉空心球, 氮掺杂石墨烯负载的硫化镉空心球具有更高的光催化活性和稳定性. 这是由于氮掺杂的石墨烯能充当优异的电子受体和传输体, 从而抑制了载流子的复合. 另外发现, 羟基自由基是可见光下降解亚甲基蓝的主要活性物种. 相似文献
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