scholarly journals Solar Light-Driven Photocatalysis Using BaFe2O4/rGO for Chlorhexidine Digluconate Contaminated Water: Comparison With Artificial UV and Visible Light-Mediated Photocatalysis

2021 ◽  
Author(s):  
Astha Singh ◽  
Brijesh Kumar Mishra
Keyword(s):  
Graphene Oxide ◽  
Visible Light ◽  
Uv Light ◽  
Organic Pollutant ◽  
Parent Compound ◽  
Degradation Pathway ◽  
Reaction Rate Constant ◽  
Barium Nitrate ◽  
Solar Light ◽  
Chlorhexidine Digluconate

Abstract Synthesis and characterization of dual functioning material is an effective approach for promotion of organic pollutant degradation through adsorption as well as photocatalysis. Herein, graphene oxide modified by addition of barium nitrate and iron to construct smooth sheet-like structure (BaFe2O4/rGO) for removal of Chlorhexidine Digluconate (CHD). Compare with GO (75.69% -UV-light ;88.17%-visible-light), BaFe2O4/rGO showed significant adsorption-photocatalysis effect under visible-light (93.95%) than UV-light (78.17%). The introduction of barium nitrate and iron into graphene oxide led to smooth porous structure with increased surface area (93.66 m2 g-1), which resulted in large number of adsorption active site and great photocatalytic activity with efficient charge separation. Although, catalysts did not mineralize CHD completely, but the parent compound mineralized to some extent, which was confirmed by the TOC measurement and UV254 absorbance variation. In addition, toxicity of degraded products was analyzed by bacterial susceptibility test on Bacillus cereus DPAML065 suggested that nontoxic byproducts of CHD formed, which led to their safe disposal. Based on the identified transformed products, the possible degradation pathway was proposed. Batch studies demonstrated that BaFe2O4/rGO is highly photoactive based on reaction rate constant (R2=0.984), where the kinetics data was well-fitted using the pseudo-first order. Moreover, efficiency of catalysts was examined under solar light to achieve the sustainability.

Visible light responsive Cu2MoS4 nanosheets incorporated reduced graphene oxide for efficient degradation of organic pollutant

2017 ◽  
Vol 418 ◽  
pp. 128-137 ◽  
Author(s):  
R. Rameshbabu ◽  
R. Vinoth ◽  
M. Navaneethan ◽  
S. Harish ◽  
Y. Hayakawa ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Organic Pollutant ◽  
Reduced Graphene

scholarly journals Sheet-on-belt branched TiO2(B)/rGO powders with enhanced photocatalytic activity

2018 ◽  
Vol 9 ◽  
pp. 1550-1557 ◽  
Author(s):  
Huan Xing ◽  
Wei Wen ◽  
Jin-Ming Wu
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Charge Separation ◽  
Reaction Rate ◽  
Uv Light ◽  
Three Dimensional ◽  
Reaction Rate Constant ◽  
Light Illumination ◽  
Reduced Graphene

TiO2(B) is usually adopted to construct phase junctions with anatase TiO2 for applications in photocatalysis to facilitate charge separation; its intrinsic photocatalytic activity, especially when in the form of one- or three-dimensional nanostructures, has been rarely reported. In this study, a sheet-on-belt branched TiO2(B) powder was synthesized with the simultaneous incorporation of reduced graphene oxide (rGO). The monophase, hierarchically nanostructured TiO2(B) exhibited a reaction rate constant 1.7 times that of TiO2(B)/rGO and 2.9 times that of pristine TiO2(B) nanobelts when utilized to assist the photodegradation of phenol in water under UV light illumination. The enhanced photocatalytic activity can be attributed to the significantly increased surface area and enhanced charge separation.

scholarly journals Degradation of Paracetamol by Photolysis Using C-N-codoped TiO2

Molekul ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. 189
Author(s):  
Vanny Yulia Safitri ◽  
Adlis Santoni ◽  
Diana Vanda Wellia ◽  
Khoiriah Khoiriah ◽  
Safni Safni
Keyword(s):  
Water Pollution ◽  
Visible Light ◽  
Uv Light ◽  
Light Irradiation ◽  
Solar Light ◽  
Tio2 Catalyst ◽  
Codoped Tio2 ◽  
Uv Light Irradiation ◽  
Optimum Weight ◽  
Visible Light Degradation

Paracetamol is generally used as analgesic and antipyretic drugs. Contamination paracetamol in the environment can occur because of waste material disposal from production site and immediate disposal of household that cause water pollution. Paracetamol is degraded by photolysis method under irradiation 10 watt UV-light (λ=365 nm), visible-light (Philips LED 13 watt 1400 lux) and solar-light with and without addition C-N-codoped TiO2catalyst. The solution is analyzed by UV-Vis spectrophotometer at λ 200-400 nm. Optimum weight of C-N-codoped TiO2 catalyst obtained is 20 mg under UV-light photolysis. Paracetamol 4 mg/L is degraded 45.48% after 120 minutes under UV-light irradiation without catalyst, and increases to be 69.31% by using 20 mg catalyst. While degradation percentage of paracetamol is 16.96 % without catalyst, the percentage increases to be 34.29% after using 20 mg catalyst for 120 minutes photolysis under visible-light. Degradation of paracetamol by solar light achieves only 12.27% in absance of catalyst for 120 minutes irradiation, but it increases significantly until 70.39% in presence of 20 mg catalyst.

Self-Assembled Reduced Graphene Oxide-TiO2 Thin Film for the Enhanced Photocatalytic Reduction of Cr(VI) Under Simulated Solar Irradiation

2019 ◽  
Vol 19 (6) ◽  
pp. 3376-3387 ◽  
Author(s):  
Hongyuan Shang ◽  
Min Ma ◽  
Fasheng Liu ◽  
Zhe Miao ◽  
Aiping Zhang
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Rate Constant ◽  
Solar Irradiation ◽  
Solar Light ◽  
X Ray ◽  
Simulated Solar Light ◽  
Reduced Graphene

In this study, reduced graphene oxide-TiO2 (RGO-TiO2) thin film was prepared by a simple self-assembly method at the gas/liquid interface. The as-prepared thin films were characterized by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), UV-visible-diffuse reflectance spectroscopy (UV-vis-DRS) and X-ray photoelectron spectroscopy (XPS). Photocatalytic activities of TiO2 and RGO-TiO2 thin film were investigated via the reduction of Cr(VI) under simulated solar light and visible light (λ > 420 nm) irradiation. The results showed that the RGO-TiO2 thin film exhibited remarkably enhanced activity for photoreduction of Cr(VI) under simulated sunlight or visible light irradiation, with a reaction rate constant of 5.7 times greater than that of pure TiO2 thin film. The main reason for enhanced photocatalytic activity is that introduction of RGO can restrain the recombination of photogenerated electron–hole pairs and reduce the aggregation of TiO2 NPs. The effects of different reaction parameters such as irradiation time, irradiation source, pH values, catalyst dosage and initial Cr(VI) concentration were investigated in detail. The highest photoreduction efficiency of Cr(VI) was achieved and the reduction rate constant k was 0.0189 min−1 during the reduction of 0.5 mg L−1 of Cr(VI) with 10 cm2 RGO-TiO2 thin film at pH 2.0 and 293 K. Moreover, different scavengers were also added in the photoreduction of Cr(VI) system to identify the reactive species. Based on the results of the present study, a possible mechanism of photoreduction on RGO-TiO2 thin film under simulated solar light was proposed. Overall, this study provides a novel approach to efficiently photoreduction of Cr(VI) by RGO-TiO2 thin film.

scholarly journals Reduced Graphene Oxide/ZnIn2S4 Nanocomposite Photocatalyst with Enhanced Photocatalytic Performance for the Degradation of Naproxen under Visible Light Irradiation

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 710
Author(s):  
Kun Fu ◽  
Yishuai Pan ◽  
Chao Ding ◽  
Jun Shi ◽  
Huiping Deng
Keyword(s):  
Graphene Oxide ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Reduced Graphene Oxide ◽  
Environmental Remediation ◽  
Dominant Role ◽  
Degradation Pathway ◽  
Light Illumination ◽  
One Pot ◽  
Reduced Graphene

The development of photocatalysts with visible light response is of great significance to cope with energy crisis and environmental remediation. In this study, a visible light-driven photocatalyst reduced graphene oxide/ZnIn2S4 (rGO/ZIS) was prepared by a facile one-pot hydrothermal method. The photocatalyst was used for the degradation of naproxen under visible light illumination and it exhibited remarkably degradation efficiency (nearly 99% within 60 min). The improved photocatalytic degradation performance can be attributed to the enhancement of light adsorption capacity and effective separation of photoinduced electron–hole pairs. The reactive species quenching experiments and EPR measurements demonstrated that superoxide radical (–O2−) and hole (h+) play a dominant role in the photocatalytic degradation reactions. In addition, the degradation intermediates were identified and the degradation pathway was suggested.

scholarly journals TiO2Nanocatalysts Supported on a Hybrid Carbon-Covered Alumina Support: Comparison between Visible Light and UV Light Degradation of Rhodamine B

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Mphilisi M. Mahlambi ◽  
Ajay K. Mishra ◽  
Shivani B. Mishra ◽  
Rui W. Krause ◽  
Bhekie B. Mamba ◽  
...  
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
Uv Light ◽  
Reaction Rate Constant ◽  
Titania Nanoparticles ◽  
Impregnation Method ◽  
Alumina Support ◽  
Photodegradation Efficiency ◽  
Carbon Covered Alumina ◽  
Hybrid Carbon

Titania nanoparticles were successfully supported on carbon-covered alumina (CCA) supports via the impregnation method to form carbon-covered alumna titania (CCA/TiO2). The CCA supports were synthesised through an equilibrium adsorption of toluene 2,4-diisocyante where the N=C=O irreversibly adsorbs on the alumina and pyrolysis at 700°C affords CCA supports. These CCA/TiO2nanocatalysts were tested for their photocatalytic activity both under UV and visible light using Rhodamine B as a model pollutant. The reaction rate constant of the CCA/TiO2was found to be higher than that of unsupported titania and the reaction kinetics were found to follow an apparent first-order rate law. The CCA/TiO2nanocatalysts had a much larger surface area than the unsupported titania and they exhibited overall higher photodegradation efficiency under both UV and visible light than unsupported TiO2.

scholarly journals A Novel 2D Graphene Oxide Modified α-AgVO3 Nanorods: Design, Fabrication and Enhanced Visible-Light Photocatalytic Performance

2021 ◽  
Author(s):  
Yan Xing ◽  
Jian WU ◽  
Xin MIN ◽  
Xingao LI
Keyword(s):  
Graphene Oxide ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Light Response ◽  
Reaction Rate Constant ◽  
First Principles Calculations ◽  
Solar Absorption ◽  
In Suit ◽  
Apparent Reaction Rate Constant ◽  
Apparent Reaction Rate

Abstract Silver vanadates are promising visible-light-responded photocatalysts with suitable bandgap for solar absorption. However, the easy recombination of photogenerated carriers limits their performance. To overcome this obstacle, a novel 2D graphene oxide (GO) modified α-AgVO3 nanorods (GO/α-AgVO3) photocatalyst was designed herein to improve the separation of photocarriers. The GO/α-AgVO3 was fabricated through a facile in-suit coprecipitation method at room temperature. It was found that the as-prepared 0.5 wt.% GO/α-AgVO3 exhibited the most excellent performance for Rhodamine B (RhB) decomposition, with an apparent reaction rate constant 18 times higher than that of pure α-AgVO3 under visible-light irradiation. In light of the first-principles calculations and the heterojunction analysis, the mechanism underpinned the enhanced photocatalytic performance was proposed. The enhanced photocatalytic performance was ascribed to the appropriate bandgap of α-AgVO3 nanorods for visible light response and efficient separation of photocarriers through GO nanosheets. This work demonstrates the feasibility of overcoming the easy recombination of photogenerated carriers and provides a valuable GO/α-AgVO3 photocatalyst for pollutant degradation.

ZnO Photocatalysis Using Solar Energy for the Removal of Trace Amounts of Alfa-Methylstyrene, Diquat and Indigo Carmine from Water

2014 ◽  
Vol 17 (2) ◽  
Author(s):  
O. M. Shibin ◽  
B. Rajeev ◽  
V. Veena ◽  
E. P. Yesodharan ◽  
Yesodharan Suguna
Keyword(s):  
Visible Light ◽  
Chemical Oxygen Demand ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Indigo Carmine ◽  
Parent Compound ◽  
Oxygen Demand ◽  
Solar Photocatalyst ◽  
Significant Chemical ◽  
Trace Pollutants

AbstractSemiconductor photocatalysis using ZnO has been extensively investigated for the chemical and bacterial decontamination of water and air. In most of these cases, UV light is the source of energy and visible light induced photocatalytic degradation of trace pollutants in water has not received adequate attention. In the present study, ZnO is evaluated as a solar photocatalyst for the removal of trace amounts of three typical pollutants, i.e. alpha- Methylstyrene (AMS, a petrochemical), Diquat (herbicide) and Indigo carmine (IC, a dye) from water. Degradation by itself does not result in complete mineralisation and decontamination as seen from the significant Chemical Oxygen Demand even after the parent compound has disappeared. However, the intermediates also get mineralized eventually. The study indicates that solar photocatalysis can be used as a viable tool for the purification water contaminated with these chemicals. The degradation follows variable kinetics depending on the concentration of the substrates. H

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