scholarly journals Fe–Doped TiO2–Carbonized Medium–Density Fiberboard for Photodegradation of Methylene Blue under Visible Light

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4888
Author(s):  
Justin Alfred Pe ◽  
Sung-Phil Mun ◽  
Min Lee
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Rate Constant ◽  
Rate Constants ◽  
Medium Density Fiberboard ◽  
Continuous Treatment ◽  
Bandgap Energy ◽  
Medium Density ◽  
Blue Led ◽  
Photodegradation Rate

Fe–doped titanium dioxide–carbonized medium–density fiberboard (Fe/TiO2–cMDF) was evaluated for the photodegradation of methylene blue (MB) under a Blue (450 nm) light emitting diode (LED) module (6 W) and commercial LED (450 nm + 570 nm) bulbs (8 W, 12 W). Adsorption under daylight/dark conditions (three cycles each) and photodegradation (five cycles) were separately conducted. Photodegradation under Blue LED followed pseudo-second-order kinetics while photodegradation under commercial LED bulbs followed pseudo-first-order kinetics. Photodegradation rate constants were corrected by subtracting the adsorption rate constant except on the Blue LED experiment due to their difference in kinetics. For 8 W LED, the rate constants remained consistent at ~11.0 × 10−3/h. For 12 W LED, the rate constant for the first cycle was found to have the fastest photodegradation performance at 41.4 × 10−3/h. After the first cycle, the rate constants for the second to fifth cycle remained consistent at ~28.5 × 10−3/h. The energy supplied by Blue LED or commercial LEDs was sufficient for the bandgap energy requirement of Fe/TiO2–cMDF at 2.60 eV. Consequently, Fe/TiO2–cMDF was considered as a potential wood-based composite for the continuous treatment of dye wastewater under visible light.

scholarly journals Real roles of perylene diimides for improving photocatalytic activity

RSC Advances ◽  
2020 ◽  
Vol 10 (39) ◽  
pp. 23024-23037 ◽  
Author(s):  
Fengxia Zhang ◽  
Wenjing Li ◽  
Tianyi Jiang ◽  
Xuemei Li ◽  
Yuanyuan Shao ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Hydrothermal Method ◽  
Perylene Diimides ◽  
Photodegradation Rate ◽  
Composite Photocatalysts ◽  
Visible Light Driven

Three novel visible-light-driven composite photocatalysts were synthesized by hydrothermal method. The effects of introducing PDIs with different structures into TiO2 were evaluated by assaying the photodegradation rate of methylene blue.

scholarly journals Photocatalytic Degradation of Methylene Blue and Methyl Orange by Y-PTC Metal-Organic Framework

2021 ◽  
Vol 7 (2) ◽  
pp. 129-141
Author(s):  
Adawiah Adawiah ◽  
Muhammad Derry Luthfi Yudhi ◽  
Agustino Zulys
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Metal Organic Framework ◽  
Light Irradiation ◽  
Bandgap Energy ◽  
Metal Organic ◽  
Organic Framework

The yttrium based metal-organic framework (MOF) Y-PTC was synthesized by the solvothermal method using perylene as the linker and yttrium as metal ion. This study aims to assess the photocatalytic activity of yttrium-perylenetetracarboxylate (Y-PTC) metal-organic framework (MOF) toward methylene blue and methyl orange under visible light irradiation. The results of the FTIR analysis showed that Y-PTC MOF had a different structure and composition from its precursor (Na4PTC). The Y-PTC MOF has a bandgap energy value of 2.20 eV with a surface area of 47.7487 m2/g. The SEM-EDS analysis showed an elemental composition of yttrium, carbon, and oxygen, were 6.9%, 72.1% and 20.7%, respectively. Furthermore, Y-PTC MOF was able to adsorb dyes at the optimum by 78.10% and 35.57% toward methylene blue (MB) and methyl orange (MO) at the dispersion period of 60 mins. Y-PTC MOF exhibited photocatalytic activity towards the degradation of methylene blue and methyl orange under visible light irradiation. The addition of H2O2 inhibited Y-PTC photocatalytic activity towards MO degradation from 50.89% to 26.38%. In contrast to MO, the addition of H2O2 had a positive effect on MB, which increased the degradation from 87.56% to 91.65%. Therefore, Y-PTC MOF possessed the potential of a photocatalyst material in dyes degradation under visible light irradiation.

Preparation of Visible-Light Active Mn-Doped TiO2 Photocatalyst and its Photodegradation of Methylene Blue from Solution

2014 ◽  
Vol 989-994 ◽  
pp. 531-535
Author(s):  
Yin Chen ◽  
Xiao Jun Ma
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Doping Concentration ◽  
Sol Gel ◽  
Mn Doping ◽  
Enhanced Absorption ◽  
Photodegradation Rate ◽  
Visible Light Active ◽  
Mn Doped

Mn-doped TiO2nanocrystal photocatalysts were prepared by the sol-gel method using MnSO4·H2O as manganese source. The catalysts were characterized by XRD, SEM, EPR, UV-Vis, their photocatalytic activity for methylene blue (MB) degradation was investigated. The results showed that Mn was doped into the crystal lattice of TiO2, and had no influence on TiO2crystal structure; the size of TiO2nanoparticle gradually decreased with Mn doping concentration increasing. The Mn-doped TiO2catalysts have enhanced absorption in the visible light region, and its visible light absorptivity increased with Mn doping concentration increasing. The UV-Vis showed the Mn-doped TiO2showed higher photocatalytic activity than the undoped TiO2for methylene blue degradation under visible light irradiation. It is also found that the MB photodegradation rate of Mn-doped TiO2improved by 46% than that of the undoped TiO2.

scholarly journals Understanding the Role of Complexation of Fluoroquinolone and β-Lactam Antibiotics with Iron (III) on the Photodegradation under Solar Light and UVC Light

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2603
Author(s):  
Efraím A. Serna-Galvis ◽  
Yudy L. Martínez-Mena ◽  
Jazmín Porras ◽  
Yenny Ávila-Torres ◽  
Javier Silva-Agredo ◽  
...  
Keyword(s):  
Rate Constant ◽  
Rate Constants ◽  
Structural Changes ◽  
Iron Concentration ◽  
Solar Light ◽  
Ferric Ions ◽  
Photodegradation Rate ◽  
Lactam Ring ◽  
Complexation Effects

Antibiotics elimination by some photochemical processes involves ferric ions, but little is discussed about the fundamental aspects of complexation effects on their degradation. This study compares the photodegradation of two fluoroquinolones, three β-lactams, and their ferric complexes in deionized water. The complexed antibiotics were more recalcitrant than the free antibiotics to the solar light action (the photodegradation rate constants diminished by more than 50%). To better study the photodegradation, other experiments considering two representative cases (ciprofloxacin and dicloxacillin) were performed. For ciprofloxacin, as the iron amount was increased from 0 to 7.5 µmol L−1, its photodegradation rate constant decreased from 0.017 to 0.004 min−1. In contrast, for dicloxacillin, the increase in iron concentration (from 0 to 7.5 µmol L−1) accelerated its photodegradation (the rate constant augmented from 0 to 0.0026 min−1). When UVC light was used, the degradations of free and complexed antibiotics were very close, exhibiting values of degradation rate constants between 0.030 and 0.085 min−1. The antimicrobial activity (AA) was eliminated when 90% of ciprofloxacin and 90–95% of dicloxacillin were degraded. The AA removal was associated with structural changes in relevant moieties of antibiotics, such as fluorine and piperazyl ring for ciprofloxacin, or β-lactam ring for dicloxacillin.

scholarly journals TiO2-rGO Composite for Photocatalytic Decolorization of Methylene Blue Under the Visible Light Illumination

2021 ◽  
Vol 9 (4) ◽  
pp. 167
Author(s):  
Ulfa Farizka Hidayati ◽  
Anthoni B. Aritonang ◽  
Lia Destiarti
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Uv Light ◽  
Bandgap Energy ◽  
Light Illumination ◽  
X Ray Diffraction ◽  
Visible Light Illumination ◽  
Blue Solution ◽  
Ft Ir

Titanium dioxide-reduced graphene oxide (TiO2-rGO) was synthesized by hydrothermal method using TiO2 powder and rGO precursor from graphite rod by modified Marcano Method. The obtained TiO2-rGO photocatalyst was characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Diffuse reflectance UV (DRUV). Based on XRD diffractogram, it is known that TiO2 has an anatase crystal phase. In the FTIR spectrum, it was observed that there was an absorption peak at the wavenumber of 1630 cm-1 from the vibration (C=C) as an indication that the C atom was incorporated into the TiO2 structure. The incorporation of C atoms into the TiO2 structure to form TiO2-rGO causes the bandgap energy to decrease from 3.29 eV to 3.20 eV. The photocatalytic activity was tested against decolorization of methylene blue solution for 180 minutes under visible light illumination from a 50 watt LED lamp. Every 10 minutes, absorbance was measured using a UV-Vis spectrophotometer at a wavelength of 664 nm. TiO2-rGO photocatalyst has better photocatalytic activity with %D of 96.39% under UV light and 84.32% under visible light illumination, while TiO2 is only able to degrade 93.87% and 36.55%, respectively.

Visible Light Active Ce-doped TiO2 Nanoparticles for Photocatalytic Degradation of Methylene Blue

2016 ◽  
Vol 13 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Rani P. Barkul ◽  
Farah-Naaz A. Shaikh ◽  
Sagar D. Delekar ◽  
Meghshyam K. Patil
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Tio2 Nanoparticles ◽  
Doped Tio2 ◽  
Visible Light Active

Determination of rate constants of redox reactions of second order from current-less potential-time curves by a simplified graphical-numerical method

1983 ◽  
Vol 48 (5) ◽  
pp. 1358-1367 ◽  
Author(s):  
Antonín Tockstein ◽  
František Skopal
Keyword(s):  
Numerical Method ◽  
Explicit Form ◽  
Rate Constant ◽  
Optimization Algorithm ◽  
Rate Constants ◽  
Redox Reactions ◽  
Second Order ◽  
Wide Region ◽  
Recurrent Formula

A method for constructing curves is proposed that are linear in a wide region and from whose slopes it is possible to determine the rate constant, if a parameter, θ, is calculated numerically from a rapidly converging recurrent formula or from its explicit form. The values of rate constants and parameter θ thus simply found are compared with those found by an optimization algorithm on a computer; the deviations do not exceed ±10%.

The Effect of p-Toluidine on the Two-Step Electroreduction of Zn(II) in Water-Methanol and Water-Dimethylformamide

1999 ◽  
Vol 64 (4) ◽  
pp. 585-594 ◽  
Author(s):  
Barbara Marczewska
Keyword(s):  
Electron Transfer ◽  
Binary Mixtures ◽  
Rate Constant ◽  
Rate Constants ◽  
Electrode Surface ◽  
Mercury Electrode ◽  
Forward Rate ◽  
Solvent Molecules ◽  
Activated Complex

The acceleration effect of p-toluidine on the electroreduction of Zn(II) on the mercury electrode surface in binary mixtures water-methanol and water-dimethylformamide is discussed. The obtained apparent and true forward rate constants of Zn(II) reduction indicate that the rate constant of the first electron transfer increases in the presence of p-toluidine. The acceleration effect may probably be accounted for by the concept of the formation on the mercury electrode an activated complex, presumably composed of p-toluidine and solvent molecules.

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