Samarium and Nitrogen Co‐Doped Bi2WO6 Photocatalysts: Synergistic Effect of Sm3+/Sm2+ Redox Centers and N‐Doped Level for Enhancing Visible‐Light Photocatalytic Activity

Samarium and nitrogen co‐doped Bi₂WO₆ 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 Bi₂WO₆ 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 Bi₂WO₆ possessed strong visible‐light absorption. Remarkably, the samarium and nitrogen co‐doped Bi₂WO₆ exhibited higher photocatalytic activity than single‐doped and pure Bi₂WO₆ under visible‐light irradiation. Radical trapping experiments indicated that holes (h⁺) and superoxide radicals ( ^. O₂^?) 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 Sm³⁺/Sm²⁺ redox pair centers and the N‐doped level. The mechanism of the excellent photocatalytic activity of Sm‐N‐Bi₂WO₆ is also discussed.     

Fe~(3+)掺杂三维分级纳米Bi_2WO_6的合成及其光催化活性增强机理(英文)

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。     

Fe3+掺杂三维分级纳米Bi2WO6的合成及其光催化活性增强机理

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。     

Br-掺杂Bi2WO6的水热法合成及其可见光催化性能

以Bi（NO₃）₃·5H₂O和Na₂WO₄·2H₂O为主要原料,采用水热法合成了纯相Bi₂WO₆,并对其进行非金属离子Br^-掺杂改性。采用XRD、SEM、TEM、XPS、Raman、PL和DRS研究了Br^-掺杂对Bi₂WO₆的物相结构、形貌和可见光催化性能的影响。结果表明,Br^-掺杂可有效提高Bi₂WO₆的可见光催化性能,当掺杂量（物质的量百分数）为8%时,溴掺杂Bi₂WO₆的光催化性能最好,可见光照射40 min后,可降解96.73%的罗丹明-B,与未掺杂Bi₂WO₆相比,其降解率提高了36.32%。     

Br~-掺杂Bi_2WO_6的水热法合成及其可见光催化性能

以Bi(NO_3)_3·5H_2O和Na_2WO_4·2H_2O为主要原料,采用水热法合成了纯相Bi_2WO_6,并对其进行非金属离子Br-掺杂改性。采用XRD、SEM、TEM、XPS、Raman、PL和DRS研究了Br~-掺杂对Bi_2WO_6的物相结构、形貌和可见光催化性能的影响。结果表明,Br-掺杂可有效提高Bi_2WO_6的可见光催化性能,当掺杂量(物质的量百分数)为8%时,溴掺杂Bi_2WO_6的光催化性能最好,可见光照射40 min后,可降解96.73%的罗丹明-B,与未掺杂Bi_2WO_6相比,其降解率提高了36.32%。     

Micelle‐Directing Synthesis of Ag‐Doped WO3 and MoO3 Composites for Photocatalytic Water Oxidation and Organic‐Dye Adsorption

In this paper, an Ag‐doped WO₃ (and MoO₃) composite has been prepared by following a simple micelle‐directed method and high‐temperature sintering route. The as‐prepared samples were characterized by X‐ray diffraction, inductively coupled plasma, transmission electron microscopy, X‐ray photoelectron spectroscopy, UV/Vis diffuse reflectance spectroscopy, Brunauer–Emmett–Teller, photoluminescence spectroscopy, and electrochemical impedance spectroscopy techniques. The photocatalytic experiments reveal that their oxygen‐production rates are up to 95.43 μmol (75.45 μmol) for Ag‐doped WO₃ (MoO₃), which is 9.5 (7.3) times higher than that of pure WO₃: 9.012 μmol (MoO₃: 9.00 μmol) under visible‐light illumination (λ ≥420 nm), respectively. The improvement of their photocatalytic activity is attributed to the enhancement of their visible‐light absorption and the separation efficiency of photogenerated carriers by Ag doping. Moreover, Ag‐doped WO₃ (MoO₃) also shows excellent adsorption of rhodamine B (RhB) and methylene blue (MB) in aqueous solution, with maximum adsorption capacities towards RhB and MB of 822 and 820 mg g⁻¹ for Ag‐doped WO₃, and 642 and 805 mg g⁻¹ for Ag‐doped MoO₃, respectively.     

BiOI/Bi2WO6对甲基橙和苯酚的光催化降解及光催化机理

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-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/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。     

BiOI/Bi_2WO_6对甲基橙和苯酚的光催化降解及光催化机理(英文)

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。     

稀土离子Tm3+掺杂Bi2WO6的可见光催化性能

以Na₂WO₄·2H₂O和Bi（NO₃）₃·5H₂O为主要原料,采用水热法合成了稀土离子Tm³⁺掺杂的Bi₂WO₆光催化剂。采用XRD、SEM、TEM、Raman、PL、DRS研究了Tm³⁺掺杂Bi₂WO₆的物相,微观形貌和可见光催化性能。结果表明,Tm³⁺掺杂有效提高了Bi₂WO₆的光催化性能,当掺杂量为6%时,样品的光催化性能最好,可见光照射30 min后,对罗丹明B的降解效率达到91.27%,而可见光照射5 h后,对焦糖色素的降解效率达45.25%。与未掺杂Bi₂WO₆相比,分别提高了27.78%和35.22%。     

Dual-Plasmon Resonance Coupling Promoting Directional Photosynthesis of Nitrate from Air

Photocatalysis, particularly plasmon-mediated photocatalysis, offers a green and sustainable approach for direct nitrogen oxidation into nitrate under ambient conditions. However, the unsatisfactory photocatalytic efficiency caused by the limited localized electromagnetic field enhancement and short hot carrier lifetime of traditional plasmonic catalysts is a stumbling block to the large-scale application of plasmon photocatalytic technology. Herein, we design and demonstrate the dual-plasmonic heterojunction (Bi/Cs_xWO₃) achieves efficient and selective photocatalytic N₂ oxidation. The yield of NO₃⁻ over Bi/Cs_xWO₃ (694.32 μg g⁻¹ h⁻¹) are 2.4 times that over Cs_xWO₃ (292.12 μg g⁻¹ h⁻¹) under full-spectrum irradiation. The surface dual-plasmon resonance coupling effect generates a surge of localized electromagnetic field intensity to boost the formation efficiency and delay the self-thermalization of energetic hot carriers. Ultimately, electrons participate in the formation of ⋅O₂⁻, while holes involve in the generation of ⋅OH and the activation of N₂. The synergistic effect of multiple reactive oxygen species drives the direct photosynthesis of NO₃⁻, which achieves the overall-utilization of photoexcited electrons and holes in photocatalytic reaction. The concept that the dual-plasmon resonance coupling effect facilitates the directional overall-utilization of photoexcited carriers will pave a new way for the rational design of efficient photocatalytic systems.     

Synthesis of TiO2/Bi2WO6 nanofibers with electrospinning technique for photocatalytic methyl blue degradation

TiO₂/Bi₂WO₆ 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 m² g^?1) and porous structure. Besides, the TiO₂/Bi₂WO₆ 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.     

稀土离子Tm3+掺杂Bi2WO6的可见光催化性能

以Na_2WO_4·2H_2O和Bi(NO_3)_3·5H_2O为主要原料,采用水热法合成了稀土离子Tm~(3+)掺杂的Bi_2WO_6光催化剂。采用XRD、SEM、TEM、Raman、PL、DRS研究了Tm~(3+)掺杂Bi_2WO_6的物相,微观形貌和可见光催化性能。结果表明,Tm~(3+)掺杂有效提高了Bi_2WO_6的光催化性能,当掺杂量为6%时,样品的光催化性能最好,可见光照射30 min后,对罗丹明B的降解效率达到91.27%,而可见光照射5 h后,对焦糖色素的降解效率达45.25%。与未掺杂Bi_2WO_6相比,分别提高了27.78%和35.22%。     

Zn对砖块状单斜WO3光催化活性的影响

利用简单的方法合成了Zn掺杂砖块状WO₃材料，并用罗丹明B对其光催化性能进行了评估。利用X射线衍射、拉曼光谱、扫描电镜、紫外可见漫反射光谱、红外光谱和X射线光电子能谱分析等技术对合成材料进行了表征，结果表明适量Zn掺杂可保持WO₃的砖块状形貌。光催化结果表明Zn掺杂量（质量分数）为5%的WO₃光催化性能最好，这是因为该材料内形成了大量的氧空位且羟基含量较高。     

Fabrication of an efficient ternary TiO2/Bi2WO6 nanocomposite supported on g-C3N4 with enhanced visible-light- photocatalytic activity: Modeling and systematic optimization procedure

In this study, a ternary TiO₂/g-C₃N₄/Bi₂WO₆ nanocomposite was prepared via a facial approach. The final structure was applied as a new photocatalyst for the removal of brilliant green (BG) dye, as a model of organic pollutants, from the aqueous solution. The results of FESEM, EDS with mapping, XRD, FTIR, UV–vis DRS, PL, and EIS analyses further demonstrate the successful establishment of heterojunction between TiO_2, g-C₃N₄, and Bi₂WO₆. Integration of g-C₃N₄ and Bi₂WO₆ with TiO2 was remarkably decreased the band gap energy of TiO₂ to 2.68 eV (from 3.15 eV). The effects of various experimental factors such as TiO₂/g-C₃N₄/Bi₂WO₆ dosage, initial BG concentration, visible irradiation time, and pH on the photocatalyst behavior of TiO₂/g-C₃N₄/Bi₂WO₆ were investigated by 2 ^k-1 factorial design. The results of the analysis of variance demonstrate these experimental factors are effective on the BG degradation efficiency. The response surface methodology was applied to achieve the optimization procedure of BG degradation. According to these results, the complete BG removal efficiency was obtained for the optimal conditions of 15.76 mg of TiO₂/g-C₃N₄/Bi₂WO₆ nanocomposite, an initial BG concentration of 10 ppm, pH of 9, and time duration of 70 min. The improved photocatalytic performance of ternary TiO₂/g-C₃N₄/Bi₂WO₆ nanocomposite was related to the formation of heterojunction between TiO_2, g-C₃N₄, and Bi₂WO₆, significant light adsorption ability, and low recombination of photogenerated carriers.     

Photocatalytic oxidation of acetaldehyde by hybrid Pt/WO3–MOR photocatalysts under visible or sunlight irradiation

A hybrid photocatalyst was prepared from visible light-responsive Pt/WO₃ and siliceous mordenite (MOR) zeolite by simple impregnation with an aqueous solution of (NH₄)₁₀W₁₂O₄₁·5H₂O. Unmodified Pt/WO₃ had low photocatalytic activity in gas phase oxidation of acetaldehyde because of its low surface area (3–5 m²/g). In contrast, the Pt/WO₃–MOR had higher photocatalytic activity under focused sunlight and Xe lamp irradiation. Pt/WO₃–MOR with low WO₃ content (<20 wt%) adsorbed sufficient acetaldehyde, but absorption of light in the visible region was low. The optimum zeolite content enhancing the photocatalytic activity of Pt/WO₃ was estimated to be 30–50 % (w/w). Adsorption of the gaseous reactants and the efficiency of absorption of incident light are both important aspects of high photocatalytic activity.     

水热法制备Pr掺杂Bi2WO6三维花状微球的光催化性能

通过水热法制备稀土Pr掺杂Bi₂WO₆三维花状微球,利用XRD、SEM、N₂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-Bi₂WO₆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。     

水热法制备Pr掺杂Bi2WO6三维花状微球的光催化性能

通过水热法制备稀土Pr掺杂Bi₂WO₆三维花状微球,利用XRD、SEM、N₂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-Bi₂WO₆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。     

Flower-like Bi2WO6/ZnO composite with excellent photocatalytic capability under visible light irradiation

The photocatalytic ability of ZnO is improved through the addition of flower-like Bi₂WO₆ to prepare a Bi₂WO₆/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 N₂ adsorption-desorption isotherms. After modification, the band gap energy of Bi₂WO₆/ZnO is reduced from 3.2 eV for ZnO to 2.6 eV. Under visible light irradiation, the Bi₂WO₆/ZnO composite shows an excellent photocatalytic activity for degrading methylene blue (MB) and tetracycline. The photo-degradation efficiencies of (0.3:1) Bi₂WO₆/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) Bi₂WO₆/ZnO exhibits a higher transient photocurrent density of approximately 4.5 μA compared with those of bare Bi₂WO₆ and ZnO nanoparticles. The successful recombination of Bi₂WO₆ 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 [O₂]^? 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.     

Enhanced visible‐light‐driven photocatalytic activity of F doped reduced graphene oxide ‐ Bi2WO6 photocatalyst

The reduced graphene oxide‐Bi₂WO₆ (rGO‐BWO) photocatalysts with the different R_F/O values (molar ratio of the F molar mass and the O's molar mass of Bi₂WO₆) 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.     

球状MoS2/WO3复合半导体制备及其对RhB的光催化性能

采用水热法成功制备了MoS₂/WO₃复合半导体光催化剂,分别通过SEM、TEM、EDS、XRD、Raman和DRS对催化剂的形貌,组成及结构进行表征,并用BET模型计算比表面积。对比发现球状MoS₂/WO₃对罗丹明B（RhB）的光降解效率明显高于纯WO₃、片状MoS₂/WO₃复合半导体。针对球状MoS₂/WO₃复合半导体,分别研究了MoS₂不同负载量（0.5%,1%,2%,5%,10%）对RhB光催化降解性能的影响,结果表明MoS₂含量为2%时催化效果最佳。同时,研究了溶液的pH值（pH=1,3,6,7,11）对光催化降解反应活性的影响,结果显示pH=6时降解率最高。当催化剂量增加到1 g·L^-1时,30min后RhB降解率达到96.6%。球状MoS₂/WO₃的瞬态光电流为0.050 6 mA·cm^-2,比纯WO₃提高了2.4倍。经过5次循环实验,球状MoS₂/WO₃复合半导体催化剂仍能保持90%的高降解率。