scholarly journals Synthesis Method Effect of CoFe2O4on Its Photocatalytic Properties for H2Production from Water and Visible Light

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yudith Ortega López ◽  
Hugo Medina Vázquez ◽  
Jesús Salinas Gutiérrez ◽  
Vanessa Guzmán Velderrain ◽  
Alejandro López Ortiz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Ball Milling ◽  
Synthesis Method ◽  
Milling Process ◽  
Bet Surface Area ◽  
Light Spectrum ◽  
Vis Spectroscopy ◽  
Adsorption Desorption

Currently, the need for more efficient materials that work in the visible light spectrum for hydrogen production has been increasing. Under this criterion, ferrites are ideal because their energetic properties are favorable to photocatalysis as they have a low band gap (1.5 to 3 ev). In this particular research, ferrite is presented as a hydrogen producer. Cobalt ferrites were synthesized by chemical coprecipitation (CP) and ball milling (BM) for comparison of their performance. The characterization of the materials was carried out with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET surface area, UV-VIS spectroscopy, and water adsorption/desorption tests. Evaluation of the photocatalytic activity under visible light was followed by gas chromatography. The results showed that cobalt ferrite by ball milling had a higher photocatalytic activity; this is attributed to the vacancies generated during the milling process at which the sample was exposed.

scholarly journals Palladium nanoparticles anchored to anatase TiO2 for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

2015 ◽  
Vol 6 ◽  
pp. 428-437 ◽  
Author(s):  
Kah Hon Leong ◽  
Hong Ye Chu ◽  
Shaliza Ibrahim ◽  
Pichiah Saravanan
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Plasmon Resonance ◽  
Visible Light ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Palladium Nanoparticles ◽  
Noble Metals ◽  
Visible Region ◽  
Bet Surface Area

Freely assembled palladium nanoparticles (Pd NPs) on titania (TiO2) nano photocatalysts were successfully synthesized through a photodeposition method using natural sunlight. This synthesized heterogeneous photocatalyst (Pd/TiO2) was characterized through field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), BET surface area, UV–vis diffuse reflectance spectra (UV-DRS), Raman and photoluminescence (PL) analyses. The simple and smart synthesis anchored well the deposition with controlled Pd NPs size ranging between 17 and 29 nm onto the surface of TiO2. Thus, it gives the characteristic for Pd NPs to absorb light in the visible region obtained through localized surface plasmon resonance (LSPRs). Apparently, the photocatalytic activity of the prepared photocatalysts was evaluated by degrading the endocrine disrupting compound (EDC) amoxicillin (AMX) excited under an artificial visible light source. In the preliminary run, almost complete degradation (97.5%) was achieved in 5 h with 0.5 wt % Pd loading and the degradation followed pseudo-first-order kinetics. The reusability trend proved the photostability of the prepared photocatalysts. Hence, the study provides a new insight about the modification of TiO2 with noble metals in order to enhance the absorption in the visible-light region for superior photocatalytic performance.

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.

scholarly journals Effect of Different Calcination Temperatures on the Structural and Photocatalytic Performance of Bi-TiO2/SBA-15

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Jing Ma ◽  
Jia Chu ◽  
Liangsheng Qiang ◽  
Juanqin Xue
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Calcination Temperatures ◽  
New Novel ◽  
Vis Spectroscopy ◽  
Novel Material ◽  
Adsorption Desorption

The new novel material Bi-TiO2/SBA-15 was synthesized by an easy wet impregnation method. A combination of XRD, XPS, Raman, N2adsorption-desorption isotherm measurement, TEM, and solid state UV-Vis spectroscopy has been used to characterize the Bi-TiO2/SBA-15 material. It was found that SBA-15 retained the ordered hexagonal mesostructure after incorporation of TiO2and Bi. The photodecomposition of rhodamine B (RhB) in aqueous medium was selected to evaluate the photocatalytic performance of Bi-TiO2/SBA-15 under visible light irradiation (λ≥420 nm). The experiment results indicated that Bi-TiO2/SBA-15 exhibited higher photocatalytic activities than pure TiO2and Bi2O3. The influences of calcination temperature were studied. It strongly influenced the activity of the samples. The sample calcined at 550°C shows the highest photocatalytic activity in the decomposition of RhB under visible light. The catalyst preserved almost its initial photocatalytic activity after six reuses.

Enhancement of visible light photocatalytic activity of tantalum oxynitride and tantalum nitride by coupling with bismuth oxide; an example of composite photocatalysis

2015 ◽  
Vol 1738 ◽  
Author(s):  
Shiba P Adhikari ◽  
Lifeng Zhang ◽  
Michael Gross ◽  
Abdou Lachgar
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Bismuth Oxide ◽  
Synthesis Method ◽  
Visible Region ◽  
Solution Chemistry ◽  
Tantalum Nitride ◽  
Electromagnetic Spectrum ◽  
Vis Spectroscopy ◽  
Photocatalytic Activities

ABSTRACTComposite photocatalysts comprised of two semiconducting oxides, with suitable band gaps and band positions, have been reported as an effective approach to enhance photocatalytic activity in the visible region of the electromagnetic spectrum. Here, we report the synthesis, characterization, and photocatalytic evaluations of semiconducting composites made by combing bismuth oxide with either tantalum oxynitride or tantalum nitride. Visible light active composites were synthesized using solution chemistry synthesis method. The composites were characterized by powder X- ray diffraction (PXRD), diffuse reflectance UV-Vis spectroscopy, and photoluminescence (PL). Their photocatalytic activities were evaluated for generation of hydrogen from an aqueous methanol solution under visible light irradiation (λ≥ 420 nm). The as-prepared composite catalysts are found to have longer photogenerated charge-carrier life time, resulting in enhanced photocatalytic activities.

The Photocatalysis Properties of Heterostructured WO3-TiO2 Composite Prepared by Waste WC-TiC Hardmetal

2013 ◽  
Vol 873 ◽  
pp. 603-611
Author(s):  
Yi Long Yang ◽  
Jin Shu Wang ◽  
Yong Li Li ◽  
Jun Shu Wu ◽  
Hong Yi Li
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Critical Role ◽  
Nitrogen Adsorption ◽  
Light Illumination ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Vis Spectroscopy ◽  
Adsorption Desorption

We reported a facile hydrothermal route for the preparation of WO3TiO2 composite nanoparticles (TWCNs) using waste WC-TiC hardmetal in the presence of hydrofluoric acid (HF). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and nitrogen adsorption/desorption analysis were employed for structural and composition analyses of the TWCNs. Our results suggested that HF was not only strongly involved in the growth of WO3, but also played a critical role in the etching effect for TWCN product. The photocatalytic activity of TWCNs was investigated by UV-vis spectroscopy. Dye molecules could be rapidly decomposed with TWCNs photocatalyst under visible light illumination. The enhanced photocatalytic activity is attributed to well matched band edge positions of WO3 and TiO2, and the large specific surface area of TWCNs in view of the incorporation of mesopores. The results presented here are expected to make a contribution toward the development of recycling waste resource delicately for photocatalytic water purification.

scholarly journals Synthesis and Characterization of CdS/TiO2-Montmorillonite Nanocomposite with Enhanced Visible-Light Absorption

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Feng-shan Zhou ◽  
Dai-mei Chen ◽  
Bao-lin Cui ◽  
Wei-heng Wang
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Cds Nanoparticles ◽  
X Ray Diffraction ◽  
Visible Light Absorption ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Adsorption Desorption

Sodium montmorillonite (MMT) was chosen as the carrier; a serial of CdS/TiO2-MMT nanocomposites with enhanced visible-light absorption ability was prepared by hydrothermal synthesis method combination with semiconductor compound modification method. The samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV-Vis) spectroscopy; the results showed that TiO2and CdS nanoparticles were loaded on the surface of montmorillonite uniformly. N2adsorption-desorption experiment showed that the specific surface area of TiO2/montmorillonite nanocomposite made by this method can reach 200 m2/g and pore-size distribution was from 4 to 6 nm; UV-Vis showed that the recombination of CdS and TiO2enhanced visible-light absorption ability of samples of TiO2/montmorillonite and visible-light absorption ability increase with the increased of the adsorption of CdS.

Novel p–n junction UiO-66/BiOI photocatalysts with efficient visible-light-induced photocatalytic activity

2018 ◽  
Vol 77 (5) ◽  
pp. 1441-1448 ◽  
Author(s):  
Yuejin Li ◽  
Xili Shang ◽  
Changhai Li ◽  
Xiaoming Huang ◽  
Jingjing Zheng
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Salicylic Acid ◽  
Visible Light ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Uv Visible ◽  
Adsorption Desorption ◽  
Junction Structure ◽  
First Time

Abstract Novel visible-light-induced UiO-66/BiOI photocatalysts with a p–n junction structure have been prepared for the first time through a facile hydrothermal method. The prepared photocatalysts were characterized using the powder X-ray diffraction, high resolution transmission electron microscopy, scanning electron microscopy, UV–visible diffuse reflectance spectra, and N2 adsorption–desorption (Brunauer–Emmett–Teller) techniques respectively. The photodegradation performances of UiO-66/BiOI photocatalysts were evaluated by photodegrading salicylic acid under visible-light irradiation. The UiO-66/BiOI composites displayed much higher photocatalytic efficiencies than pure BiOI under visible light. When the content of UiO-66 was 5.2 wt%, the composite (UiO-66/BiOI-2) has the best photocatalytic activity. Most of the salicylic acid molecules can be degraded in 100 min. The degradation rate of UiO-66/BiOI-2 samples is higher than single BiOI and UiO-66. The enhanced photocatalytic performance of UiO-66/BiOI may be ascribed to the formation of p–n heterojunctions between BiOI and UiO-66, which facilitates the transfer and separation of the photogenerated charge carriers. After recycling of the photocatalyst for five times for the photodegradation of salicylic acid, more than 85% of salicylic acid could still be degraded in the fifth cycle, implying that the as-prepared photocatalysts are highly stable.

scholarly journals Synthesis, Characterization, and Photocatalytic Activity of Zn-Doped SnO2/Zn2SnO4Coupled Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Tiekun Jia ◽  
Junwei Zhao ◽  
Fang Fu ◽  
Zhao Deng ◽  
Weimin Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Synthesis Method ◽  
Diffuse Reflection Spectroscopy ◽  
Transmission Electron ◽  
20 Nm ◽  
Adsorption Desorption

Zn-doped SnO2/Zn2SnO4nanocomposites were prepared via a two-step hydrothermal synthesis method. The as-prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-vis diffuse reflection spectroscopy, and adsorption-desorption isotherms. The results of FESEM and TEM showed that the as-prepared Zn-doped SnO2/Zn2SnO4nanocomposites are composed of numerous nanoparticles with the size ranging from 20 nm to 50 nm. The specific surface area of the as-prepared Zn-doped SnO2/Zn2SnO4nanocomposites is estimated to be 71.53 m2/g by the Brunauer-Emmett-Teller (BET) method. The photocatalytic activity was evaluated by the degradation of methylene blue (MB), and the resulting showed that Zn-doped SnO2/Zn2SnO4nanocomposites exhibited excellent photocatalytic activity due to their higher specific surface area and surface charge carrier transfer.

scholarly journals Photocatalytic activity of Pr-modified TiO2 for the degradation of bisphenol A

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Denise S. Cordeiro ◽  
Fernando L. Cassio ◽  
Larissa Ciccotti ◽  
Thiago L. R. Hewer ◽  
Paola Corio ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Bisphenol A ◽  
Pore Diameter ◽  
Sol Gel ◽  
Bandgap Energy ◽  
Photocatalytic Efficiency ◽  
Average Pore ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Adsorption Desorption

AbstractPraseodymium doped TiO2 nanoparticles were successfully prepared by the sol–gel method and characterized by X-ray powder diffraction, N2 adsorption–desorption isotherm, and UV–vis spectroscopy. The effects of the dopant on the crystallite size, specific surface area, average pore diameter, pore volume, and bandgap energy were investigated. The photocatalytic activity of the catalysts was evaluated by bisphenol A degradation and mineralization, which is a representative endocrine disruptor. Furthermore, under visible light irradiation the Pr-modified TiO2 photocatalysts exhibited higher photocatalytic efficiency than unmodified TiO2. When praseodymium was loaded (1.0–5.0%) onto the surface of TiO2, the rates of degradation and mineralization were increased 3–5 times.

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