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81.
基于密度泛函理论的第一性原理平面波赝势方法, 运用Vasp方法计算了Eu, N掺杂及Eu/N共掺杂锐钛矿TiO2的结构, 并分析了其电子及光学性质. 通过计算发现有一些Eu的4f态电子在Eu掺杂锐钛矿TiO2的体系的费米能级附近出现杂质能级, 并且N掺杂会使得锐钛矿TiO2的禁带宽度减小. 对于共掺杂体系而言, Eu/N共掺杂的协同效应能导致锐钛矿TiO2的晶格畸变及禁带宽度减小. 与此同时, 计算得到的光吸收谱表明Eu/N混合掺杂锐钛矿TiO2展现出了明显的光谱吸收边缘红移. 这些计算结果表明Eu/N共掺杂锐钛矿TiO2具有优良的光催化活性.
关键词:
2')" href="#">TiO2
共掺杂
可见光催化剂
密度泛函理论 相似文献
82.
With the ever‐increasing concerns on environmental pollution and energy crisis, it is of great urgency to develop high‐performance photocatalyst to eliminate organic pollutants from wastewater and produce hydrogen via water splitting. Herein, a polypyridyl‐based mixed covalent CuI/II complex with triangular {Cu3} and rhombic {Cu2Cl4} subunits alternately extended by mixed SCN– and Cl– heterobridges [Cu4(DNP)(SCN)Cl4]n ( 1 ) [DNP = 2,6‐bis(1,8‐naphthyridine‐2‐yl)pyridine] was solvothermally synthesized and employed as a dual‐functional co‐photocatalyst. Resulting from a narrowed band‐gap of 1.07 eV with suitable redox potential and unsaturated CuI/II sites, the complex together with H2O2 can effectively degrade Rhodamine B and methyl orange up to 87.4 and 88.2 %, respectively. Meanwhile, the complex mixed with H2PtCl6 can also accelerate the photocatalytic water splitting in the absence of a photosensitizer with the hydrogen production rate of 27.5 μmol · g–1 · h–1. These interesting findings may provide informative hints for the design of the multiple responsive photocatalysts. 相似文献
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85.
采用溶剂热法制备氨基功能化Fe_3O_4磁性材料(NH_2@nFe_3O_4),通过浸渍法将磺化酞菁铝(AlPcS)负载于NH_2@nFe_3O_4。材料的傅立叶红外、漫反射、X射线衍射、扫描电镜、透射电镜、振动磁强计等表征表明:AlPcS主要通过静电作用与NH_2@nFe_3O_4结合,AlPcS-NH_2@nFe_3O_4平均粒径为127 nm,饱和磁化强度为75.3 emu·g-1。在可见光和空气作用下,该功能化磁性材料对降解弱碱性水溶液中环境内分泌干扰物双酚A(BPA)具有较高的光敏化活性。随着AlPcS负载量的增加活性呈先升高后下降的趋势,负载量为3.4%(质量分数)的复合材料性能最佳,反应60 min后,20.0 mg·L-1BPA降解率为96%;循环使用10次,BPA降解率仍保持93%以上。通过NaN3猝灭实验探讨了反应机理,证实1O2是光敏化过程中的主要活性物种。 相似文献
86.
Sayoko Shironita 《Applied Surface Science》2008,254(23):7604-7607
Pt particles in a uniform dispersion were successfully synthesized on single-site photocatalyst (Ti-containing mesoporous silica (Ti-HMS)) under UV-light irradiation by a photo-assisted deposition (PAD) method. Using an aqueous solution of H2PtCl6 as a precursor, the nano-sized Pt metal particles were deposited directly on the photo-excited tetrahedrally coordinated titanium oxide moieties within the framework of mesoporous silica (PAD-Pt/Ti-HMS). The Pt catalysts were characterized by means of XRD, Pt LIII-edge XAFS, CO adsorption, and TEM analysis. It was demonstrated that Pt particles had mean diameter of 4 nm in a narrow size distribution. Meanwhile, Pt particles loaded by a conventional impregnation method (imp-Pt/Ti-HMS) showed a wide size distribution ranging from 2 to 30 nm. The PAD-Pt/Ti-HMS catalyst was more active in the CO oxidation than the conventional impregnated imp-Pt/Ti-HMS catalyst. It is suggested that the PAD method using single-site photocatalyst is a useful and unique technique to prepare fine and uniform Pt nanoparticles. 相似文献
87.
《Arabian Journal of Chemistry》2020,13(11):8424-8457
Nowadays, increasing extortions regarding environmental problems and energy scarcity have stuck the development and endurance of human society. The issue of inorganic and organic pollutants that exist in water from agricultural, domestic, and industrial activities has directed the development of advanced technologies to address the challenges of water scarcity efficiently. To solve this major issue, various scientists and researchers are looking for novel and effective technologies that can efficiently remove pollutants from wastewater. Nanoscale metal oxide materials have been proposed due to their distinctive size, physical and chemical properties along with promising applications. Cupric Oxide (CuO) is one of the most commonly used benchmark photocatalysts in photodegradation owing to the fact that they are cost-effective, non-toxic, and more efficient in absorption across a significant fraction of solar spectrum. In this review, we have summarized synthetic strategies of CuO fabrication, modification methods with applications for water treatment purposes. Moreover, an elaborative discussion on feasible strategies includes; binary and ternary heterojunction formation, Z-scheme based photocatalytic system, incorporation of rare earth/transition metal ions as dopants, and carbonaceous materials serving as a support system. The mechanistic insight inferring photo-induced charge separation and transfer, the functional reactive radical species involved in a photocatalytic reaction, have been successfully featured and examined. Finally, a conclusive remark regarding current studies and unresolved challenges related to CuO are put forth for future perspectives. 相似文献
88.
A good photocatalyst with high efficiency can be synthesized easily using eco-friendly materials and processes. Our synthesized samples exhibit all of the aforementioned features. In this work, manganese co-doped ZnO at different weight percentages (3, 6, 9, and 15 wt.%) with and without 1.5 wt.% aluminum was synthesized by hydrothermal method, and their photocatalytic activity in aqueous solutions of methyl orange (MO) was investigated under visible light. The structural and optical properties of the samples were characterized using X-ray powder diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, and diffuse reflectance spectroscopy. In this work, Mn2+ ions in the 9%Mn/ZnO sample and Mn2+, Al3+ ions in the (9%Mn, 1.5%Al)/ZnO sample calcined at 800 °C were replaced instead with some Zn2+ ions in hexagonal wurtzite structures of ZnO. These structures were found next to each other in the form of a hexagonal shape that created 3D-hexagonal-like ZnO nanostructures. Finally, nanoparticles (NPs) and nano hexagonal-like ZnO nanostructures were, respectively, dispersed on the surface of 3D-hexagonal-like structure of 9%Mn/ZnO and (9%Mn, 1.5%Al)/ZnO. Diffuse reflectance spectroscopy analysis showed that the (9%Mn, 1.5%Al)/ZnO sample had more light absorption than 9%Mn/ZnO. However, contrary to our expectations, the 9%Mn/ZnO sample had better decolorization efficiency (94%) after 60 min under visible light, which could be attributed to a significant increase in the level of recombination by the aluminum ions. 相似文献
89.
Polyaniline (PANI)/MIL-88A(Fe) (Px@M88) composites were constructed through a simple one-pot hydrothermal method. The photocatalytic and photo-Fenton activities of Px@M88 composites toward reduction of Cr(VI) and degradation organic pollutants were explored by white light irradiation. PANI, as a conductive polymer, can improve MIL-88A(Fe)’s conductivity and the efficiency of photogenerated e−–h+ pair separation. In the presence of H2O2, a photo-Fenton reaction occured to boost the degradation efficiency of organic pollutants like bisphenol A. In addition, P9@M88 showed excellent recycling and stability in cycling experiments. Finally, a possible reaction mechanism for photocatalytic degradation was proposed and verified by X-ray photoelectron spectroscopy and electron spin resonance determination and electrochemical characterizations. 相似文献
90.
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/Ag2WO4/g‐C3N4 (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 Ag2WO4 and Ag/Ag2WO4. Characterization and photocatalytic tests showed that the strong coupling effect between the Ag/Ag2WO4 nanoparticles and the exfoliated ultrathin g‐C3N4 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