scholarly journals Influence of Operational Parameters on the Photocatalytic Activity of Powdered TiO2 for the Reduction of CO2

2014 ◽  
Vol 14 (2) ◽  
pp. 122-130 ◽  
Author(s):  
Oman Zuas ◽  
Jin Seog Kim ◽  
Jarnuzi Gunlazuardi
Keyword(s):  
Photocatalytic Activity ◽  
Reaction Pathway ◽  
Co2 Reduction ◽  
Product Formation ◽  
Operational Parameters ◽  
Illumination Time ◽  
Reaction Media

In this report, the results from a study on the influence of operational parameters on TiO2 photocatalytic activity for CO2 reduction under an ultraviolet-visible (UV-vis) illumination are presented. The results indicated that the TiO2 was found to be active for CO2 reduction with CH3OH as the major products, while other minor products (CO, CH4, and C2H4) were also detected. In addition, the formation of such reduction products was obviously influenced by the operational parameters. Under this study, the optimum operational parameters for CO2 reduction at 298 °K were determined to be: NaOH concentration 0.2 M, TiO2 dosage 2 g/L, volume of the reaction media 75 mL, the pressure of system 800 kPa. It was also found that the increase in UV-vis illumination time have increased the yield of product formation. A possible reaction pathway for the formation of the reduction products is also discussed.

Enhanced photocatalytic activity of CeO2 using β-cyclodextrin on visible light assisted decoloration of methylene blue

2013 ◽  
Vol 69 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Sakthivel Pitchaimuthu ◽  
Ponnusamy Velusamy
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Inclusion Complexation ◽  
Processing Parameters ◽  
Operational Parameters ◽  
Illumination Time ◽  
Operational Conditions ◽  
Electron Microscopy Analysis ◽  
Initial Ph

An attempt has been made to enhance the photocatalytic activity of CeO2 for visible light assisted decoloration of methylene blue (MB) dye in aqueous solutions by β-cyclodextrin (β-CD). The inclusion complexation patterns between host and guest (i.e., β-CD and MB) have been confirmed with UV–visible spectral data. The interaction between CeO2 and β-CD has also been characterized by field emission scanning electron microscopy analysis. The photocatalytic activity of the catalyst under visible light was investigated by measuring the photodegradation of MB in aqueous solution. The effects of key operational parameters such as initial dye concentration, initial pH, CeO2 concentration as well as illumination time on the decolorization extents were investigated. Among the processing parameters, the pH of the reaction solution played an important role in tuning the photocatalytic activity of CeO2. The maximum photodecoloration rate was achieved at basic pH (pH 11). Under the optimum operational conditions, approximately 99.6% dye removal was achieved within 120 min. The observed results indicate that the decolorization of the MB followed a pseudo-first order kinetics.

Enhanced photocatalytic activity of CO2 reduction to methanol through the use of a novel-structured CuCaAg2Se–graphene–TiO2 ternary nanocomposite

2020 ◽  
Vol 44 (39) ◽  
pp. 16795-16809 ◽  
Author(s):  
Zambaga Otgonbayar ◽  
Kwang Youn Cho ◽  
Won-Chun Oh
Keyword(s):  
Photocatalytic Activity ◽  
Catalytic Activity ◽  
Charge Transfer ◽  
Effective Charge ◽  
Co2 Reduction ◽  
Nanocomposite Materials ◽  
Ternary Nanocomposite ◽  
Key Factor ◽  
Effective Charge Transfer

Effective charge transfer is a key factor in enhancing the catalytic activity of photocatalytic nanocomposite materials.

scholarly journals Rhodium(ii)-catalyzed C–H aminations using N-mesyloxycarbamates: reaction pathway and by-product formation

2019 ◽  
Vol 10 (3) ◽  
pp. 718-729 ◽  
Author(s):  
Emna Azek ◽  
Maroua Khalifa ◽  
Johan Bartholoméüs ◽  
Matthias Ernzerhof ◽  
Hélène Lebel
Keyword(s):  
Reaction Pathway ◽  
Product Formation ◽  
Dft Study ◽  
By Products

DFT study to elucidate the mechanism of Rh-catalyzed C–H aminations with N-mesyloxycarbamates and the pathway by which by-products formed.

scholarly journals Synthesis of novel MgAl layered double oxide grafted TiO2 cuboids and their photocatalytic activity on CO2 reduction with water vapor

2015 ◽  
Vol 5 (6) ◽  
pp. 3288-3295 ◽  
Author(s):  
Cunyu Zhao ◽  
Lianjun Liu ◽  
Guiying Rao ◽  
Huilei Zhao ◽  
Luhui Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Water Vapor ◽  
Co2 Reduction ◽  
Double Oxide

Photocatalytic CO2 reduction with H2O by hybrid MgAl-LDO/TiO2 materials.

scholarly journals Microwave-Assisted Solvothermal Synthesis of Chalcogenide Composite Photocatalyst and Its Photocatalytic CO2 Reduction Activity under Simulated Solar Light

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 789
Author(s):  
Gang-Juan Lee ◽  
Yu-Hong Hou ◽  
Hsin-Ting Huang ◽  
Wenmin Wang ◽  
Cong Lyu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Photocatalytic Activity ◽  
Co2 Reduction ◽  
Carbon Dioxide Reduction ◽  
Photoluminescence Intensity ◽  
Composite Photocatalyst ◽  
Microwave Assisted ◽  
Reduction Activity ◽  
Operation Conditions ◽  
Co Doped

A novel heterostructure consisting of Ru and Cu co-doped ZnS nanopowders (RCZS) into a MoS2-graphene hybrid (MSG) is successfully prepared by the microwave-assisted solvothermal approach. RCZS nanopowders are fabricated on the surface of MSG, which produces a nanoscale interfacial between RCZS and MSG. As the photo-excited electrons of RCZS can easily migrate to MoS2 through graphene by hindering the electron and hole (e– and h+) recombination, the photocatalytic activity could be improved by effective charge transfer. As RCZS are anchored onto the MSG, the photoluminescence intensity of the chalcogenide composite photocatalyst obviously decreases. In addition, a quaternary ruthenium and copper-based chalcogenide RCZS/MSG is able to improve the harvest and utilization of light. With the increase in the concentrations of Ru until 4 mol%, the band gap significantly decreases from 3.52 to 2.73 eV. At the same time, moderate modification by ruthenium can decrease the PL intensity compared to the pristine CZS/MSG sample, which indicates the enhancement of e– and h+ separation by Ru addition. The photocatalytic activity of as-synthesized chalcogenide composite photocatalysts is evaluated by the photocatalytic carbon dioxide reduction. Optimized operation conditions for carbon dioxide reduction have been performed, including the concentration of NaOH solution, the amount of RCZS/MSG photocatalyst, and the content of co-doped ruthenium. The doping of ruthenium would efficiently improve the performance of the photocatalytic activity for carbon dioxide reduction. The optimal conditions, such as the concentration of 2 M NaOH and the 0.5RCZS/MSG dosage of 0.05 g L–1, provide the maximum methane gas yield of 58.6 μmol h−1 g–1.

Photocatalytic Activity of Metal Oxide Supported Gallium Oxide for CO2 Reduction with Water

2020 ◽  
Vol 93 (5) ◽  
pp. 694-700 ◽  
Author(s):  
Ryota Ito ◽  
Masato Akatsuka ◽  
Akiyo Ozawa ◽  
Muneaki Yamamoto ◽  
Tetsuo Tanabe ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Metal Oxide ◽  
Gallium Oxide ◽  
Co2 Reduction

scholarly journals Conjugated Electron Donor–Acceptor Hybrid Polymeric Carbon Nitride as a Photocatalyst for CO2 Reduction

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1779 ◽  
Author(s):  
Asif Hayat ◽  
Mati Ur Rahman ◽  
Iltaf Khan ◽  
Javid Khan ◽  
Muhammad Sohail ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Molecular Orbital ◽  
Density Functional ◽  
Carbon Nitride ◽  
Co2 Reduction ◽  
Characterization Methods ◽  
Base Functions ◽  
Activity Performance ◽  
Donor Acceptor ◽  
Polymeric Carbon

This work incorporates a variety of conjugated donor-acceptor (DA) co-monomers such as 2,6-diaminopurine (DP) into the structure of a polymeric carbon nitride (PCN) backbone using a unique nanostructure co-polymerization strategy and examines its photocatalytic activity performance in the field of photocatalytic CO2 reduction to CO and H2 under visible light irradiation. The as-synthesized samples were successfully analyzed using different characterization methods to explain their electronic and optical properties, crystal phase, microstructure, and their morphology that influenced the performance due to the interactions between the PCN and the DPco-monomer. Based on the density functional theory (DFT) calculation result, pure PCN and CNU-DP15.0 trimers (interpreted as incorporation of the co-monomer at two different positions) were extensively evaluated and exhibited remarkable structural optimization without the inclusion of any symmetry constraints (the non-modified sample derived from urea, named as CNU), and their optical and electronic properties were also manipulated to control occupation of their respective highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Also, co-polymerization of the donor–acceptor 2,6-diamino-purine co-monomer with PCN influenced the chemical affinities, polarities, and acid–base functions of the PCN, remarkably enhancing the photocatalytic activity for the production of CO and H2 from CO2 by 15.02-fold compared than that of the parental CNU, while also improving the selectivity.

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