scholarly journals The Influence of Calcination Temperature on Photocatalytic Activity of TiO2-Acetylacetone Charge Transfer Complex towards Degradation of NOx under Visible Light

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1463
Author(s):  
Lucas A. Almeida ◽  
Margarita Habran ◽  
Rafael dos Santos Carvalho ◽  
Marcelo E. H. Maia da Costa ◽  
Marco Cremona ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Visible Light ◽  
Calcination Temperature ◽  
Charge Transfer Complex ◽  
Light Exposure ◽  
Sol Gel ◽  
Solar Spectrum ◽  
Photocatalytic Efficiency ◽  
Nanocrystalline Tio2

The improvement of photocatalytic activity of TiO2-based nanomaterials is widely investigated due to the tentative of their industrialization as environmental photocatalysts and their inherently low solar spectrum sensitivity and rapid recombination of charge carriers. Coupling of oxygen-based bidentate diketone to nanocrystalline TiO2 represents a potential alternative for improving the holdbacks. Formation of TiO2-acetylacetone charge transfer complex (CTC) by sol-gel route results in a hybrid semiconductor material with photodegradation activity against toxic NOx gas. In this research, the influence of the chelating agent acetylacetone (ACAC) content on the CTC photocatalytic efficiency under visible light was evaluated. A high content of ACAC in the CTC is not a decisive factor for efficiency of photocatalytic reactions. In fact, the highest efficiency for NOx degradation (close to 100%, during 1 h of visible light exposure) was reported for the material calcined in air at 300 °C with the content of strongly bonded acetylacetone not higher than 3 wt.%. Higher calcination temperature (400 °C) left TiO2 almost completely depleted in ACAC, while at the highest applied temperature (550 °C) a portion of anatase was transformed into rutile and the sample is free of ACAC. The analyses pointed out that superoxide anion radical (O2−) plays an active role in photo-oxidation of NOx. Our findings indicate that this CTC has both high visible light spectral sensitivity and photocatalytic efficiency.

Calcination Temperature Influence on the Microstructure and the Photocatalytic Properties of TiO2 Pillared Rectorite

2011 ◽  
Vol 197-198 ◽  
pp. 790-795
Author(s):  
Zong Wu Wei ◽  
Jian Hua Chen ◽  
Mei Qun Lin ◽  
Ye Chen
Keyword(s):  
Photocatalytic Activity ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Photocatalytic Reaction ◽  
Photocatalytic Efficiency ◽  
Temperature Influence ◽  
High Adsorption ◽  
Bet Analysis ◽  
High Adsorption Capacity ◽  
Xrd Patterns

TiO2 pillared rectorite (TPLR) had been synthesized by sol-gel method, and was characterized by XRD, TEM, BET, UV-vis DRS and FTIR. The effects of calcination temperature on the microstructure and the photocatalytic activity of the as prepared catalyst were investigated. The photocatalytic activity of the catalyst was evaluated by decomposition of Acid Red B (ARB) aqueous solution. XRD patterns revealed that TiO2 is incorporated into the interlayer of the rectorite. TEM demonstrated that TiO2 particles are present in the rectorite. The BET analysis indicated that the surface area of the sample calcined at 300°C (TPLR-300) was larger than those of other samples. The TPLR samples had high adsorption capacity and good photocatalytic efficiency in decomposition of ARB in water. FTIR spectra of the original and the recovered samples indicated that the catalyst had not chemically changed during the photocatalytic reaction.

Facile Synthesis of r-GO @Pd/TiO2 Nanocomposites and Its Photocatalytic Activity Under Visible Light

2016 ◽  
Vol 16 (4) ◽  
pp. 3557-3563 ◽  
Author(s):  
Anh Quang Dao ◽  
Bijuan Zheng ◽  
Hongwei Liu ◽  
Shuang Dong ◽  
Thanh Tuyen Le Thi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Wastewater Treatment ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Catalytic Efficiency ◽  
Average Crystallite Size ◽  
High Photocatalytic Activity ◽  
Synthesis Conditions

Reduced Graphene Oxide Wrapped Pd/TiO2 (r-GO@Pd/TiO2) which exhibited high photocatalytic activity under visible light was synthesized from commercial chemicals. The classic sol–gel method and the Ar gas bubbling composition was used in the preparation of the catalyst. Furthermore, the best Pd-doping concentration in crystals, the wrapping concentration of r-GO over nanoparticles, and the optimal calcination temperature were investigated to enhance the photocatalytic activity of the hybrid catalyst. The experimental results showed that the catalytic efficiency of r-GO@Pd/TiO2 reached maximum value at the optimum synthesis conditions: 0.7 wt% Pd-doped TiO2 by sol–gel process, calcination temperature of 550 °C, 1 mg of GO for 100 gram wrapped Pd/TiO2. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) techniques were conducted to determine the nanostructure of the catalysts. The average crystallite size of nanoparticles was 14 nm with perfect dispersion of Pd dots and wraps of r-GO membrane. Methyl Blue was used as an organic dye model to test the ability in wastewater treatment of the catalysts. A comparison between different catalysts’ characteristics was also studied. The r-GO@Pd/TiO2 showed a higher photocatalytic activity compared to Pd/TiO2 and commercial P25. Additionally, the complete dye reduction under visible light excitation indicated that wrapping r-GO round Pd/TiO2 improved the photocatalytic activity of catalysts. The determination of the stability of r-GO@Pd/TiO2 showed that its photocatalysis was persistent over several times of recycling examination. Therefore, r-GO@Pd/TiO2 in wastewater treatment.

SbVO4-TiO2 Cation Deficient Photocatalyst: Synthesis and Photocatalytic Investigation

2013 ◽  
Vol 702 ◽  
pp. 51-55
Author(s):  
Rahmatollah Rahimi ◽  
Masoumeh Mahjoub Moghaddas ◽  
Solmaz Zargari
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Vanadium Oxide ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Photocatalytic Efficiency ◽  
Visible Light Driven ◽  
Ft Ir ◽  
First Time

For the first time antimony vanadium oxide-TiO2(SbV-T) nanocomposite was synthesized via sol-gel method to improve the photocatalytic efficiency of TiO2. The samples were characterized by FT-IR, XRD, SEM, EDX, and DRS. To investigate the photocatalytic activity of the samples, the photodegradation of methyl orange was carried out under visible light irradiation with pure TiO2, SbVO4, and SbVO4-TiO2nanocomposite. The SbV-T photocatalyst exhibited higher visible light driven photocatalytic efficiency to degrade MO dye. Furthermore the effect of SbVO4 and cationic vacancies in the photocatalytic activity of the SbV-T sample are described.

scholarly journals Synthesis of N/Fe Comodified TiO2Loaded on Bentonite for Enhanced Photocatalytic Activity under UV-Vis Light

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Xi Cao ◽  
Chen Liu ◽  
Yandi Hu ◽  
Wenli Yang ◽  
Jiawei Chen
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Sol Gel ◽  
Visible Region ◽  
Nitrogen Adsorption ◽  
Single Element ◽  
Photocatalytic Efficiency ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Contaminant Degradation

To improve the efficiency of TiO2as a photocatalyst for contaminant degradation, a novel nanocomposite catalyst of (N, Fe) modified TiO2nanoparticles loaded on bentonite (B-N/Fe-TiO2) was successfully prepared for the first time by sol-gel method. The synthesized B-N/Fe-TiO2catalyst composites were characterized by multiple techniques, including scanning electron microscope (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), X-ray fluorescence (XRF), nitrogen adsorption/desorption, UV-Vis diffuse reflectance spectra (DRS), and electron paramagnetic resonance (EPR). The results showed that bentonite significantly enhanced the dispersion of TiO2nanoparticles and increased the specific surface area of the catalysts. Compared with nondoped TiO2, single element doped TiO2, or unloaded TiO2nanoparticles, B-N/Fe-TiO2had the highest absorption in UV-visible region. The photocatalytic activity of B-N/Fe-TiO2was also the highest, based on the degradation of methyl blue (MB) at room temperature under UV and visible light irradiation. In particular, the synthesized B-N/Fe-TiO2showed much greater photocatalytic efficiency than N/Fe-TiO2under visible light, the newly synthesized B-N/Fe-TiO2is going to significantly increase the photocatalytic efficiency of the catalyst using sun light.

STRUCTURAL, OPTICAL PROPERTIES AND PHOTOCATALYTIC ACTIVITY OF NANOCRYSTALLINE TiO2 THIN FILMS DEPOSITED BY SOL-GEL SPIN COATING

2019 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
KOMARAIAH DURGAM ◽  
RADHA EPPA ◽  
REDDY M. V. RAMANA ◽  
KUMAR J. SIVA ◽  
R. SAYANNA ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Photocatalytic Activity ◽  
Spin Coating ◽  
Sol Gel ◽  
Tio2 Thin Films ◽  
Nanocrystalline Tio2

Tuning the Photocatalytic Performance of Plasmonic Nanocomposites (ZnO/Aux) Driven in Visible Light

2019 ◽  
Vol 8 (1) ◽  
pp. 56-61
Author(s):  
Aneeya K. Samantara ◽  
Debasrita Dash ◽  
Dipti L. Bhuyan ◽  
Namita Dalai ◽  
Bijayalaxmi Jena
Keyword(s):  
Electron Transfer ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Transfer Rate ◽  
Photocatalytic Performance ◽  
Light Exposure ◽  
Au Nanoparticle ◽  
Electron Transfer Rate ◽  
Au Nps ◽  
Zno Nanostructure

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.

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.

scholarly journals Nickel and sulfur codoped TiO2 nanoparticles for efficient visible light photocatalytic activity

2021 ◽  
Author(s):  
Mehala Kunnamareddy ◽  
Ranjith Rajendran ◽  
Megala Sivagnanam ◽  
Ramesh Rajendran ◽  
Barathi Diravidamani
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Fourier Transforms ◽  
Phase Particle ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Bandgap Energy ◽  
Visible Light Absorption

AbstractIn this work, Nickel (Ni) and sulfur (S) codoped TiO2 nanoparticles were prepared by a sol-gel technique. The as-prepared catalyst was characterized using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), FT-Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectra (DRS) for investigating crystal structure, crystal phase, particle size and bandgap energy of these samples. The photocatalytic performances of all the prepared catalysts have been investigated for the degradation of methylene blue (MB) under visible light irradiation. It was noticed that Ni-S codoped TiO2(Ni-S/TiO2) nanoparticles exhibited much higher photocatalytic activity compared with pure, Ni and S doped TiO2 due to higher visible light absorption and probable decrease in the recombination of photo-generated charges. It was decided that the great visible light absorption was created for codoped TiO2 by the formation of impurity energy states near both the edges of the collection, which works as trapping sites for both the photogenerated charges to decrease the recombination process.

Visible-Light-Induced Photocatalytic Activity of Boron-Doped BiVO4

2014 ◽  
Vol 809-810 ◽  
pp. 890-894
Author(s):  
Dan Li ◽  
Lian Wei Shan ◽  
Gui Lin Wang ◽  
Li Min Dong ◽  
Wei Li ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Reflectance Spectroscopy ◽  
Scheelite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Boron Doped

Boron-BiVO4 samples were synthesized by sol-gel method. They were characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction. Photocatalytic activity of the obtained BiVO4 samples was investigated through degrading methylene blue (MB). The results reveal that boron-BiVO4 catalysts have monoclinic scheelite structure. The BiVO4 and Co-BiVO4 photocatalysts were responsive to visible light. Co-BiVO4 photocatalyst showed higher photocatalytic activity than pure BiVO4, resulting in the significantly improved efficiency of degradation of MB.

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