The Morphology Effect on Ca-Bi-O System Photocatalytic Property under Visible-Light Irradiation

2013 ◽  
Vol 538 ◽  
pp. 219-222 ◽  
Author(s):  
Hai Ying Wang ◽  
Ke Xiong ◽  
Yan Chun Hu ◽  
Ke Lei Zhang ◽  
Rui Xiong
Keyword(s):  
Visible Light ◽  
Surface Area ◽  
Photocatalytic Property ◽  
Solid State Reaction Method ◽  
Bet Surface Area ◽  
Visible Absorption ◽  
Visible Light Driven ◽  
Morphology Effect ◽  
Uv Visible ◽  
The Relationship

Four main phases in Ca-Bi-O systems, Ca6Bi6O15, Ca4Bi6O13, CaBi2O4 and Ca5Bi14O26 were prepared by solid-state reaction method. UV-visible absorption spectra show that the samples of CaBi2O4, Ca4Bi6O13 and Ca5Bi14O26 have visible-light reactivity with the band gap of 3.08 eV, 2.76 eV and 2.60eV, respectively. The results of SEM and BET measurements indicate that CaBi2O4 has the morphology of flower-like nanostructure and the high BET surface area, while Ca6Bi6O15, Ca4Bi6O13, and Ca5Bi14O26 have the morphology of particles of various shapes with a diameter from 200 nm to 2 μm and low BET surface area. CaBi2O4 was found to be a most efficient visible-light-driven photocatalyst in degradation MB. This work may deepen the understanding of the relationship between the photocatalytic properties and the crystal structures in Ca-Bi-O system.

scholarly journals The Photocatalytic and Antibacterial Performance of Nitrogen-Doped TiO2: Surface-Structure Dependence and Silver-Deposition Effect

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2261 ◽  
Author(s):  
Abdul Wafi ◽  
Erzsébet Szabó-Bárdos ◽  
Ottó Horváth ◽  
Mihály Pósfai ◽  
Éva Makó ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Surface Area ◽  
Photocatalytic Performance ◽  
Visible Region ◽  
Bet Surface Area ◽  
Doped Tio2 ◽  
X Ray ◽  
Nitrogen Doped ◽  
Visible Light Driven

Catalysts for visible-light-driven oxidative cleaning processes and antibacterial applications (also in the dark) were developed. In order to extend the photoactivity of titanium dioxide into the visible region, nitrogen-doped TiO2 catalysts with hollow and non-hollow structures were synthesized by co-precipitation (NT-A) and sol–gel (NT-U) methods, respectively. To increase their photocatalytic and antibacterial efficiencies, various amounts of silver were successfully loaded on the surfaces of these catalysts by using a facile photo-deposition technique. Their physical and chemical properties were evaluated by using scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive X-ray spectroscopy (TEM–EDS), Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), and diffuse reflectance spectra (DRS). The photocatalytic performances of the synthesized catalysts were examined in coumarin and 1,4-hydroquinone solutions. The results showed that the hollow structure of NT-A played an important role in obtaining high specific surface area and appreciable photoactivity. In addition, Ag-loading on the surface of non-hollow structured NT-U could double the photocatalytic performance with an optimum Ag concentration of 10−6 mol g−1, while a slight but monotonous decrease was caused in this respect for the hollow surface of NTA upon increasing Ag concentration. Comparing the catalysts with different structures regarding the photocatalytic performance, silverized non-hollow NT-U proved competitive with the hollow NT-A catalyst without Ag-loading for efficient visible-light-driven photocatalytic oxidative degradations. The former one, due to the silver nanoparticles on the catalyst surface, displayed an appreciable antibacterial activity, which was comparable to that of a reference material practically applied for disinfection in polymer coatings.

Hierarchical Brookite TiO2–Bi2MoO6 Nanospheres with Efficient Visible-Light-Driven Photocatalytic Response

2021 ◽  
Vol 21 (10) ◽  
pp. 5370-5377
Author(s):  
Ying Ma ◽  
Yu-Long Jia ◽  
Yin-He Lin ◽  
Wen-Bing Shi
Keyword(s):  
Visible Light ◽  
Surface Area ◽  
Light Absorption ◽  
Three Dimensional ◽  
Photocatalytic Property ◽  
Hierarchical Architecture ◽  
Visible Light Driven ◽  
Excellent Cycling Stability ◽  
Loading Amount ◽  
Absorption Features

Hierarchical TiO2–Bi2MoO6 nanospheres as efficient visible-light responsive photocatalyst are fabricated by dispersing brookite TiO2 nanorods on the hierarchical Bi2MoO6 nanospheres, which provides visible-light absorption and large surface area. The morphologies, surface area and light absorption features of as-prepared TiO2–Bi2MoO6 can be rational controlled by varying the loading amount of TiO2 nanorods on hierarchical Bi2MoO6 nanospheres. As a result, the TiO2–Bi2MoO6-3 yields 380 ppm CO2 production for decomposing 2-propanol at 11 h under visible light irradiation, realizing 4.4 times enhancement of photocatalytic property with respect to pure TiO2 nanorods. Moreover, the three-dimensional hierarchical architecture enables the hybrid TiO2–Bi2MoO6 excellent cycling stability.

High Surface Area SnO2 -Ta2 O5 Composite for Visible Light-driven Photocatalytic Degradation of an Organic Dye

2018 ◽  
Vol 94 (4) ◽  
pp. 633-640 ◽  
Author(s):  
Bharath Velaga ◽  
Pradeep P. Shanbogh ◽  
Diptikanta Swain ◽  
Chandrabhas Narayana ◽  
Nalini G. Sundaram
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Organic Dye ◽  
Visible Light Driven

Polyimide with enhanced π stacking for efficient visible-light-driven photocatalysis

2021 ◽  
Author(s):  
Kelian Zhang ◽  
Hanmei Li ◽  
Haixian Shi ◽  
Wei Hong
Keyword(s):  
Visible Light ◽  
Surface Area ◽  
Organic Semiconductor ◽  
Light Harvesting ◽  
Photocatalytic Efficiency ◽  
Π Stacking ◽  
Visible Light Driven ◽  
Donor Acceptor

The organic semiconductor of polyimide has received considerable attention as a chemically stable donor-acceptor photocatalyst, yet exhibits moderate photocatalytic efficiency which is limited by low surface area, insufficient light harvesting...

Effects of Synthesis Conditions on the Crystalline Phases and Photocatalytic Activities of Silver Vanadates via Hydrothermal Method

2009 ◽  
Vol 1171 ◽  
Author(s):  
Chao-Ming Huang ◽  
Guan T. Pan ◽  
Lung C. Chen ◽  
C.K. Thomas Yang ◽  
Wen S. Chang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Surface Area ◽  
Synthesis Method ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Synthesis Conditions ◽  
Vis Spectroscopy ◽  
Visible Light Driven

AbstractVisible-light-driven Ag3VO4 photocatalysts were successfully synthesized using low-temperature hydrothermal synthesis method. Under various hydrothermal conditions, the structures of silver vanadates were tuned by manipulating the hydrothermal time and the ratio of silver to vanadium. X-ray diffraction (XRD) results reveal that the powders prepared in a stoichiometric ratio consisted of pure α-Ag3VO4 or mixed phases of Ag4V2O7 and α-Ag3VO4. With increasing the Ag-to-V mole ratio to 6:1, the resulting samples were identified as pure monoclinic structure α-Ag3VO4. UV-vis spectroscopy indicated that silver vanadate particles had strong visible light absorption with associated band gaps in the range of 2.2-2.5 eV. The sample synthesized in the excess silver exhibited higher photocatalytic activity than that synthesized in a stoichiometric ratio. The powder synthesized at silver-rich at 140℃ for 4 h (SHT4) exhibited the highest photocatalytic activity among all samples. The reactivity of SHT4 (surface area, 3.52 m2 g-1) on the decomposition of gaseous benzene was about 16 times higher than that of P25 (surface area, 49.04 m2 g-1) under visible light irradiation. A well developed crystallinity of Ag3VO4 of SHT 4 was considered to enhance the photocatalytic efficiency.

Structure-controllable superhydrophobic Cu meshes for effective separation of oils with different viscosities and aqueous pollutant purification

RSC Advances ◽  
2016 ◽  
Vol 6 (21) ◽  
pp. 17642-17650 ◽  
Author(s):  
Stephen Boakye-Ansah ◽  
Yong Taek Lim ◽  
Ha-Jin Lee ◽  
Won San Choi
Keyword(s):  
Visible Light ◽  
Water Separation ◽  
Effective Separation ◽  
Visible Light Driven ◽  
Oil Water Separation ◽  
Oil Water ◽  
Surface Morphologies ◽  
The Relationship

The visible light-driven purification of aqueous pollutants after oil/water separation was demonstrated and the relationship between the surface morphologies of meshes and the viscosities of oils for effective separation was investigated.

scholarly journals Synthesis of a high-surface area V2O5/TiO2–SiO2 catalyst and its application in the visible light photocatalytic degradation of methylene blue

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24368-24376 ◽  
Author(s):  
Ajay Kumar Adepu ◽  
Srinath Goskula ◽  
Suman Chirra ◽  
Suresh Siliveri ◽  
Sripal Reddy Gujjula ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Bet Surface Area ◽  
Titanium Silicate ◽  
Ft Ir ◽  
Synthesized Materials ◽  
Visible Light Photocatalytic

In the present study, we synthesized several high-surface area V2O5/TiO2–SiO2 catalysts (vanado titanium silicate, VTS). The synthesized materials are characterized by PXRD, FE-SEM/EDAX, TEM, BET-surface area, FT-IR, UV-Vis, XPS, fluorescence and photocatalytic studies.

scholarly journals Effect of Cu, Cr, S Doped TiO2 for Transparent Plastic Bar Reinforced Concrete

2020 ◽  
Vol 10 (20) ◽  
pp. 7334
Author(s):  
Seung-Hoon Seo ◽  
Byoung-Il Kim
Keyword(s):  
Absorption Spectrum ◽  
Reinforced Concrete ◽  
Visible Light ◽  
High Performance Concrete ◽  
Test Method ◽  
Visible Absorption Spectrum ◽  
Nox Removal ◽  
Transparent Plastic ◽  
Visible Absorption ◽  
Uv Visible

In this study, after firing and powdering Cu, Cr, and S with NP-400 TiO2, an NOx removal rate test was performed according to the ISO test method to analyze the photocatalytic reactivity in visible light. The distribution of the photocatalyst and visible light reactivity on the surface of the test specimen were confirmed through SEM (Scanning electron microscope), EDS (Energy dispersive spectroscopy), XRD (X-ray diffraction), UV-visible absorption spectrum and energy band gap tests. The flowability of UHPC (Ultra high performance concrete) slightly decreased due to the increase in the photocatalyst mixing rate, but both J-Ring and L-Box test results showed that there is no problem when concrete is placed. As a result of SEM and EDS tests, good microstructure and peak values were confirmed in the test specimens doped with Cu, and as a result of the XRD test, anatase and rutile peaks were confirmed in the Cu, Cr, and S specimens. In the UV-visible absorption spectrum analysis, it was confirmed that only the specimen doped with Cu maintains a high absorption power of 0.8 up to 700 nm, and the inherent band gaps are reduced to 2.9 eV, thereby increasing the possibility of reaction in visible light. Finally, as a result of the NOx removal test by the ISO test method, about 15.8% was removed for 5 h in the specimen doped with Cu, and the removal efficiency is estimated to be possible up to about 25% when applied with the TPBRC (transparent plastic bar reinforced concrete).

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