scholarly journals One-Pot Synthesis of Sulfur-Doped TiO2/Reduced Graphene Oxide Composite (S-TiO2/rGO) with Improved Photocatalytic Activity for the Removal of Diclofenac from Water

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1621
Author(s):  
Marin Kovačić ◽  
Klara Perović ◽  
Josipa Papac ◽  
Antonija Tomić ◽  
Lev Matoh ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Charge Recombination ◽  
Solar Irradiation ◽  
One Pot ◽  
Doped Tio2 ◽  
X Ray ◽  
Sulfur Doping ◽  
Reduced Graphene ◽  
Simulated Solar Irradiation

Sulfur-doped TiO2 (S-TiO2) composites with reduced graphene oxide (rGO), wt. % of rGO equal to 0.5%, 2.75%, and 5.0%, were prepared by a one-pot solvothermal procedure. The aim was to improve photocatalytic performance in comparison to TiO2 under simulated solar irradiation for the treatment of diclofenac (DCF) in aqueous medium. The obtained composites were characterized for physical-chemical properties using thermogravimetric analysis (TGA), X-ray diffractograms (XRD), Raman, scanning electron microscopy (SEM)/energy dispersive X-ray (EDX), Brauner Emmett Teller (BET), and photoluminescence (PL) analyses, indicating successful sulfur doping and inclusion of rGO. Sulfur doping and rGO have successfully led to a decrease in photogenerated charge recombination. However, both antagonistic and synergistic effects toward DCF treatment were observed, with the latter being brought forward by higher wt.% rGO. The composite with 5.0 wt.% rGO has shown the highest DCF conversion at pH 4 compared to that obtained by pristine TiO2, despite lower DCF adsorption during the initial dark period. The expected positive effects of both sulfur doping and rGO on charge recombination were found to be limited because of the subpar interphase contact with the composite and incomplete reduction of the GO precursor. Consequent unfavorable interactions between rGO and DCF negatively influenced the activity of the studied S-TiO2/rGO photocatalyst under simulated solar irradiation.

Synthesis and characterization of barium-doped TiO2 nanocrystals for photocatalytic degradation of Acid Red 18 under solar irradiation

2017 ◽  
Vol 88 ◽  
pp. 200-206 ◽  
Author(s):  
Behzad Shahmoradi ◽  
Mohammad Amin Pordel ◽  
Meghdad Pirsaheb ◽  
Afshin Maleki ◽  
Shadi Kohzadi ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Solar Irradiation ◽  
Synthesis And Characterization ◽  
Tio2 Nanocrystals ◽  
Doped Tio2

Self-Cleaning Tests of Zn-Fe/Anatase-Coated Glass Plates under Direct and Diffuse Sunlight

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Jorge Medina-Valtierra ◽  
Jorge Ramírez-Ortiz ◽  
Claudio Frausto-Reyes
Keyword(s):  
Exposure Time ◽  
Solar Irradiation ◽  
Tio2 Films ◽  
Doped Tio2 ◽  
Diffuse Solar Radiation ◽  
Coated Glass ◽  
Solar Exposure ◽  
Typical Experiment ◽  
Glass Plates ◽  
Self Cleaning

Thin films of anatase (TiO2) doped with 1 wt. percent of zinc ferrite (ZnFe2O4) were formed on glass plates by deposition of a sol-gel mixture using an ultra-spinning technique. After the preparation, the TiO2 films with a thickness of 168-232 nm were investigated with respect to their UV absorption capability and photo-degradation of organic molecules. Microscope observations of the surface of TiO2 films showed that they exhibit a micro-granular surface. To test the self-cleaning properties of the doped TiO2 films, a layer of fluoranthene of around 6.5 mg was sprayed over the glass and then exposed to direct or diffuse solar radiation. While the coated-glass transparency was totally recovered at 88 h of direct solar exposure for the undoped anatase film, the covering of fluoranthene on the 1 wt. percent ZnFe2O4-doped TiO2 film was degraded totally at 52 h of exposure time. As complementary experiments, the same glass plates with metal oxide-doped anatase films, after spraying with a similar layer of the organic contaminant, were placed under diffuse sunlight. In a typical experiment, the covering of fluoranthene was degraded almost 100 percent at an exposure time of 48 days and the transparency of glass plates was recovered totally at 55 days of indirect solar exposure. A correlation was found between the weight losses of the solid contaminant and the intensity of the Raman vibration at 672 cm-1. It was found that under diffuse solar irradiation is possible to remove completely a fluoranthene layer generating an expected application of these active surfaces under extreme conditions.

scholarly journals Photocatalytic degradation of Direct Yellow-27 by photolysis with UV-light and solar irradiation Using N-doped TiO2

2019 ◽  
Vol 1 (2) ◽  
pp. 62
Author(s):  
Deliza . ◽  
Safni . ◽  
Diana Vanda Wellia ◽  
Toyohide Takeuchi
Keyword(s):  
Photocatalytic Degradation ◽  
Uv Light ◽  
Solar Irradiation ◽  
Doped Tio2

.

Degradation of Ametryn in Aqueous Solution by Solar/ S-Doped Titanium Dioxide Process

2010 ◽  
Vol 113-116 ◽  
pp. 1375-1378 ◽  
Author(s):  
Cheng Liu ◽  
Wei Chen
Keyword(s):  
Removal Efficiency ◽  
Degradation Rate ◽  
Solar Irradiation ◽  
Rate Coefficients ◽  
Sulfur Source ◽  
Doped Tio2 ◽  
Photo Catalyst ◽  
Hydrolysis Method ◽  
Water Ph ◽  
Acid Catalyzed

The removal efficiency of ametryn in water and the influencing factors by the combined process of solar irradiation and S-doped TiO2 were studied in detail, in which S-doped TiO2 photo-catalyst with high sunlight activity was prepared by acid catalyzed hydrolysis method with thiourea as sulfur source; As a comparison, solar/TiO2 process was studied in the meantime; The experiment results showed that ametryn could be more effectively oxidized by the solar/S-doped TiO2 process than the solar/ TiO2 one, while the removal efficiency of 60% and 40% respectively after 30 min’s irradiation; Pseudo-first-order model could be used to simulate the oxidation process in which the degradation rate coefficients were independent of the initial concentration of ametryn; Degradation rate could be greatly affected by the concentration of H2O2, the optimum concentration for the system of solar/S-doped TiO2 was found to be 20mg/L, which was 5mg/L higher than that of solar/TiO2 system; Lower water pH favored the degradation of ametryn for the change of charge density of both the ametryn molecular and photo-catalyst surface.

Microcystin-LR Degradation of Titanium Dioxide Process by Solar/ S-Doped

2010 ◽  
Vol 33 ◽  
pp. 327-331 ◽  
Author(s):  
Cheng Liu ◽  
Wei Chen ◽  
Man Wang ◽  
Zhe Cao
Keyword(s):  
Humic Acids ◽  
Degradation Rate ◽  
Oxidation Process ◽  
Solar Irradiation ◽  
Sulfur Source ◽  
Order Model ◽  
Doped Tio2 ◽  
First Order ◽  
Hydrolysis Method ◽  
Acid Catalyzed

The removal efficiency of microcystin-LR in water and the influencing factors by combined process of solar irradiation and S-doped TiO2 were studied in detail, in which S-doped TiO2 photo-catalyst with high sunlight activity was prepared by acid catalyzed hydrolysis method using thiourea as sulfur source. The experiment results showed that MC-LR could be more effectively oxidized by the solar/S-doped TiO2 process than by solar/ TiO2 process, whose removal effect were about 70% and 55% after 40 min’s irradiation, respectively. Pseudo-first-order model could be used to simulate the oxidation process. Degradation rate could be greatly affected by the concentration of H2O2, the optimum concentration for the system of solar/S-doped TiO2 was found to be 20mg/L, which was 5mg/L higher than that of solar/TiO2 system. Humic acids decreased the degradation rate, and solar/S-doped TiO2 process more easily affected, for the humic acids could not only compete with molecular MC-LR for radicals but also adsorb part of sunlight which can excite radical with TiO2.

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