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.

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.

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.

scholarly journals Modified Sol-Gel Synthesis of Carbon Nanotubes Supported Titania Composites with Enhanced Visible Light Induced Photocatalytic Activity

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Quanjie Wang ◽  
Yanqing Wang ◽  
Baorong Duan ◽  
Mengmeng Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Photocatalytic Activity ◽  
Carbon Nanotube ◽  
Visible Light ◽  
Sol Gel ◽  
High Photocatalytic Activity ◽  
Raw Material ◽  
Tetrabutyl Titanate ◽  
Multiwalled Carbon ◽  
Photodegradation Efficiency

Multiwalled carbon nanotube (MWCNT) enhanced MWCNT/TiO2nanocomposites were synthesized by surface coating of carbon nanotube with mixed phase of anatase and rutile TiO2through a modified sol-gel approach using tetrabutyl titanate as raw material. The morphological structures and physicochemical properties of the nanocomposites were characterized by FT-IR, XRD, DTA-TG, TEM, and UV-Vis spectra. The results show that TiO2nanoparticles with size of around 15 nm are closely attached on the sidewall of MWCNT. The nanocomposites possess good absorption properties not only in the ultraviolet but also in the visible light region. Under irradiation of ultraviolet lamp, the prepared composites have the highest photodegradation efficiency of 83% within 4 hours towards the degradation of Methyl Orange (MO) aqueous solution. The results indicate that the carbon nanotubes supported TiO2nanocomposites exhibit high photocatalytic activity and stability, showing great potentials in the treatment of wastewater.

Hydrothermal Synthesis of Visible Light Active SnO2-SnS2 Nanocomposite Photocatalyst for the Reduction of Cr(VI) in Water

2013 ◽  
Vol 709 ◽  
pp. 7-10
Author(s):  
Jing Li ◽  
Xi Hua Du ◽  
Wei Min Dai ◽  
Yong Cai Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Sno2 Nanoparticles ◽  
High Photocatalytic Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Light Active ◽  
Composition Structure

A low temperature (130 °C) hydrothermal method was proposed for the synthesis of SnO2-SnS2 nanocomposite. The composition, structure and optical property of the as-synthesized SnO2-SnS2 nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic activity was tested by the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation. It was found that the as-synthesized SnO2-SnS2 nanocomposite exhibited high photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation, whereas SnO2 nanoparticles displayed no photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation.

TEM Study of Rutile-Phase TiO2 Nanosheets

2013 ◽  
Vol 850-851 ◽  
pp. 156-159
Author(s):  
Xin Yan Wu ◽  
Wei Xiong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Rutile Phase ◽  
High Photocatalytic Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process

TiO2 nanosheets have been successfully synthesized via a simple sol-gel process. These nanostructures were characterized by transmission electron microscopy (TEM) and x-ray energy dispersive spectrometer (EDS). The sheet-shaped single-crystalline nanostructures are pure rutile-phase structure, with landscape dimension of 10-45 nm. EDS investigation confirms that the TiO2 nanosheets are only composed of Ti and O, and the atomic ration of Ti and O is close to 1:2. High photocatalytic activity might be expected for those TiO2 nanosheets due to their large surface area.

Visible-Light Driven LaNiO3 Nanosized Photocatalysts Prepared by a Sol-Gel Process

2011 ◽  
Vol 279 ◽  
pp. 83-87 ◽  
Author(s):  
Pei Song Tang ◽  
He Sun ◽  
Feng Cao ◽  
Jin Tian Yang ◽  
Sheng Liang Ni ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Light Absorption ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
High Photocatalytic Activity ◽  
Visible Light Absorption ◽  
Average Grain Size ◽  
Sol Gel Process

The LaNiO3 nanoparticles were prepared by a sol-gel process. The LaNiO3 nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). XRD and SEM demonstrate the successful synthesis of single phase perovskite LaNiO3 and an average grain size of 80 nm in diameter. It was found that the as-prepared LaNiO3 shows strong visible-light absorption with absorption onset of 545 nm, indicating a narrow optical band gap of 2.28 eV. Consequently, LaNiO3 nanoparticles show high visible-light photocatalytic activity for decomposition of methyl orange in comparison with the commercial Degussa P25. The photocatalytic experiment shows the high photocatalytic activity for the decomposition of methyl orange under visible-light irradiation, which is attributed to the strong visible-light absorption.

scholarly journals Photocatalytic Degradation of Tetracycline by a Novel (CMC)/MIL-101(Fe)/β-CDP Composite Hydrogel

2021 ◽  
Vol 8 ◽  
Author(s):  
Hui Zhang ◽  
Liang Zhou ◽  
Jing Li ◽  
Sijia Rong ◽  
Jianping Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Photogenerated Electron ◽  
High Photocatalytic Activity ◽  
Composite Hydrogel ◽  
Light Irradiation ◽  
Structure And Property ◽  
Photocatalytic Material

Herein, we report a novel carboxymethyl cellulose (CMC)/MIL-101 (Fe)/poly(β-cyclodextrin) (β-CDP) hydrogel with high photocatalytic activity. β-CDP can significantly enhance the photoactivity of MIL-101(Fe) in the hydrogel prepared by a simple solvothermal method. The structure and property of this composite hydrogel were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Tetracycline was selected as a model pharmaceutical antibiotic to evaluate the photocatalytic activity of the composite hydrogel under visible light irradiation and darkness, respectively. This composite hydrogel shows excellent activity for degrading pharmaceutical antibiotics under visible light irradiation. The increased photocatalytic activity can be attributed to β-CDP, which acts as a promoter and affords an efficient separation of photogenerated electron-hole pairs of MIL-101(Fe). Moreover, the composite hydrogel is shown to have good water retainability. The hydrogel is inexpensive and shows high photocatalytic activity. Hence, it can be used as an efficient photocatalytic material.

scholarly journals Controlled Growth of LDH Films with Enhanced Photocatalytic Activity in a Mixed Wastewater Treatment

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 807 ◽  
Author(s):  
Zhongchuan Wang ◽  
Pengfei Fang ◽  
Parveen Kumar ◽  
Weiwei Wang ◽  
Bo Liu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Environmental Remediation ◽  
High Photocatalytic Activity ◽  
Manufacturing Cost ◽  
Transport Pathways ◽  
Layer Spacing ◽  
Double Hydroxides

Due to multiple charge transport pathways, adjustable layer spacing, compositional flexibility, low manufacturing cost, and absorption of visible light, layered double hydroxides (LDHs) are a promising material for wastewater treatment. In this study, LDH films and Fe-doped LDH films with different metal ions (Ni, Al, Fe) on the surface of conductive cloth were successfully prepared and applied for the photocatalytic degradation of wastewater containing methyl orange and Ag ions under visible-light irradiation. The chemical state of Fe ions and the composition of LDHs on methyl orange photodegradation were investigated. The experimental results showed that LDH films exhibited high photocatalytic activity. The photocatalytic activity of LDH films on methyl orange improved in the mixed wastewater, and the Fe-doped NiAl–LDH films exhibited best visible-light photocatalytic performance. The analysis showed that Ag ions in the mixed wastewater were reduced by the LDH films and subsequently deposited on the surface of the LDH films. The Ag nanoparticles acted as electron traps and promoted the photocatalytic activity of the LDH films on methyl orange. Thus, we have demonstrated that prepared LDH films can be used in the treatment of mixed wastewater and have broad application prospects in environmental remediation and purification processes.

Nonporous Nitrogen and Ruthenium Co-Doped Titania Films for Photocatalysis

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940043 ◽  
Author(s):  
O. Linnik ◽  
L. Khoroshko
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Structural Properties ◽  
Sol Gel ◽  
High Photocatalytic Activity ◽  
Gel Technique ◽  
Titania Films ◽  
Doped Titania ◽  
Co Doped

Nitrogen and ruthenium co-doped titania films synthesized by sol–gel technique exhibit high photocatalytic activity under both UV and visible light. Incorporation of nitrogen and ruthenium ions in titania lattice is proven by XPS. Both doping agents affected the structural properties of the films.

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