scholarly journals Benzothiazole heterogeneous photodegradation in nano α-Fe 2 O 3 /oxalate system under UV light irradiation

2018 ◽  
Vol 5 (6) ◽  
pp. 180322 ◽  
Author(s):  
Xiangyun Han ◽  
Xi Zhang ◽  
Lei Zhang ◽  
Mei Pan ◽  
Jinlong Yan
Keyword(s):  
Liquid Chromatography ◽  
Oxalic Acid ◽  
High Performance ◽  
Uv Light ◽  
Transformation Products ◽  
Light Irradiation ◽  
Order Kinetic ◽  
Uv Light Irradiation ◽  
Order Kinetic Model ◽  
Set Up

The photodegradation of benzothiazole (BTH) in wastewater with the coexistence of iron oxides and oxalic acid under UV light irradiation was investigated. Results revealed that an effective heterogeneous photo-Fenton-like system could be set up for BTH abatement in wastewater under UV irradiation without additional H 2 O 2 , and 88.1% BTH was removed with the addition of 2.0 mmol l −1 oxalic acid and 0.2 g l −1 α-Fe 2 O 3 using a 500 W high-pressure mercury lamp (365 nm). The degradation of BTH in the photo-Fenton-like system followed the first-order kinetic model. The photoproduction of hydroxyl radicals (·OH) in different systems was determined by high-performance liquid chromatography. Identification of transformation products by using liquid chromatography coupled with high resolution tandem mass spectrometry provided information about six transformation products formed during the photodegradation of BTH. Further insight was obtained by monitoring concentrations of the sulfate ion ( SO 4 2 − ) and nitrate ion ( NO 3 − ) , which demonstrated that the intermediate products of BTH could be decomposed ultimately. Based on the results, the potential photodegradation pathway of BTH was also proposed.

scholarly journals Photocatalytic oxidation of nitrite ion over carbon nitride

2018 ◽  
Vol 14 (1-2) ◽  
pp. 174-178 ◽  
Author(s):  
Siti Maryam Jasman ◽  
Hendrik Oktendy Lintang ◽  
Siew Ling Lee ◽  
Leny Yuliati
Keyword(s):  
High Performance ◽  
Photocatalytic Oxidation ◽  
Carbon Nitride ◽  
Uv Light ◽  
Nitrogen Adsorption ◽  
Thermal Polymerization ◽  
Light Irradiation ◽  
Polymerization Process ◽  
Nitrite Ion ◽  
Uv Light Irradiation

Nitrite ion (NO2-) is a toxic inorganic contaminant, which is widely used in industry and agriculture as a food preservative and a fertilizing agent. One of the methods to reduce the toxicity of the NO2- is by oxidizing it into less hazardous compounds, such as nitrate ion (NO3-). In this study, we demonstrated that a simple and green photocatalytic process can be employed to oxidize the NO2- to NO3- over a metal free-carbon nitride photocatalyst under ultraviolet (UV) light irradiation. The carbon nitride was synthesized via pyrolysis of urea precursor by a thermal polymerization process at 823 K for 4 hours. The prepared carbon nitride was then characterized by using X-ray diffractometer (XRD), field emission scanning electron microscope (FESEM), diffuse reflectance UV-visible (DR UV-vis), fluorescence, and Fourier transform infrared (FTIR) spectrophotometers, as well as nitrogen  adsorption-desorption isotherm analyzer. All the characterization results supported the successful synthesis of the carbon nitride. The carbon nitride was then used as the photocatalyst for oxidation of NO2- to NO3- under UV light irradiation for 3 h. The decrease of the NO2- and the formation of the NO3- were analyzed by using a high performance liquid chromatography (HPLC) equipped with Hypersil GoldTM PFP column. The mobile phase used was a mixture of methanol (MeOH) and water (H2O) with the ratio of MeOH:H2O was 30:70. The addition of orthophosphoric acid was required to set the pH at 2.5. The flow rate was fixed at 0.8 ml min-1 and the monitored wavelength was 220 nm. It was revealed that carbon nitride could oxidize NO2- to NO3- with a moderate conversion of 15%. Fluorescence quenching showed that there were good interactions between the emission sites of carbon nitride and the NO2- molecules. The good interactions would be one driving force for the carbon nitride to act as a good photocatalyst to oxidize the NO2- to NO3-. The oxidation pathway by the photogenerated species was also proposed.

Photoelectrocatalytic degradation of Rhodamine B using graphene and titanium dioxide composite catalyst

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744098
Author(s):  
Yu Zhao ◽  
Wen-Han Du ◽  
Lei Chen ◽  
Jin Xiao ◽  
Chao Xiong ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Rhodamine B ◽  
High Performance ◽  
Separation Efficiency ◽  
Uv Light ◽  
Synthesis Method ◽  
Light Irradiation ◽  
Composite Catalyst ◽  
Uv Light Irradiation ◽  
Photoelectrocatalytic Degradation

Graphene and titanium dioxide (TiO2) composite catalyst has been synthesized by hydrothermal synthesis method, and used for the degradation of Rhodamine B (Rh.B) in water. The photoelectrocatalytic activity of this composite was evaluated by decomposing of Rh.B in water under visible or UV light irradiation. The degradation results indicated that the photoelectrocatalytic performance of this composite catalyst was greatly enhanced due to the improved adsorption performance and separation efficiency of photo-generated carriers possibly. The composite with graphene content of 10 wt.% exhibited superior activity under UV light irradiation. After 30 min of reaction, the photoelectrocatalytic degradation ratio of Rh.B was about 96% when pH [Formula: see text] 6–7. The results of this work provide a good method for the treatment of organic wastewater with high performance.

scholarly journals Oxalic Acid-Induced Photodissolution of Ferrihydrite and the Fate of Loaded As(V): Kinetics and Mechanism

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1143 ◽  
Author(s):  
Hai-Tao Ren ◽  
Jing Han ◽  
Ting-Ting Li ◽  
Qi Lin ◽  
Jia-Horng Lin ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Iron Oxides ◽  
Uv Light ◽  
Water Environment ◽  
Light Irradiation ◽  
Aquatic Environments ◽  
Light Illumination ◽  
Acidic Water ◽  
Uv Illumination ◽  
Uv Light Irradiation

The fate of arsenic in the water environment is of great concern. Here, the influences of oxalic acid and UV light illumination on the dissolution of naked ferrihydrite (Fhy), Fhy loaded with As(V) [Fhy*-As(V)], as well as the fate of As(V) at pH 3.0 were studied. With the assistance of oxalic acid, complexes of Fe(III)-oxalic acid produced on Fhy/Fhy*-As(V) were reduced to Fe(II)-oxalic acid by photo-induced electrons under UV light irradiation. UV light has nearly no impact on the release of As(V) in the system of Fhy*-As(V) without the assistance of oxalic acid. Nevertheless, in the existence of oxalic acid, UV light illumination resulted in the contents of liberated As(V) decreased by 775–1300% compared to that without light. Considering the coexistence of As(V), oxalic acid as well as iron oxides in aquatic environments, the present study revealed that UV illumination could enhance the retention of As(V) on Fhy in the acidic water environment containing oxalic acid.

scholarly journals Photocatalytic and Antibacterial Properties of Ag-CuFe2O4@WO3 Magnetic Nanocomposite

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 298
Author(s):  
Mohammad Hossein Sayadi ◽  
Najmeh Ahmadpour ◽  
Shahin Homaeigohar
Keyword(s):  
Drug Concentration ◽  
Uv Light ◽  
Antibacterial Properties ◽  
Order Kinetic ◽  
Magnetic Photocatalyst ◽  
First Order ◽  
Photodegradation Efficiency ◽  
Uv Light Irradiation ◽  
Efficient Performance ◽  
Order Kinetic Model

This study aimed to synthesize a new magnetic photocatalytic nanosystem composed of Ag-CuFe2O4@WO3 and to investigate its photodegradation efficiency for two drug pollutants of Gemfibrozil (GEM) and Tamoxifen (TAM) under Ultraviolet (UV) light irradiation. In this regard, the effect of pH, catalyst dosage, and drug concentration was thoroughly determined. The largest photodegradation level for GEM (81%) and TAM (83%) was achieved at pH 5, a photocatalyst dosage of 0.2 g/L, drug concentration of 5 mg/L, and contact time of 150 min. The drug photodegradation process followed the pseudo first-order kinetic model. In addition to the photodegradation effect, the nanocomposites were proved to be efficient in terms of antibacterial activity, proportional to the Ag doping level. The Ag-CuFe2O4@WO3 nanocomposite exhibited a stable, efficient performance without an obvious catalytic loss after five successive cycles. Taken together, the developed magnetic photocatalyst is able to simultaneously disinfect wastewater streams and to degrade pharmaceutical contaminants and thus shows a promising potential for purification of multi-contaminant water systems.

scholarly journals TiO2-Powdered Activated Carbon (TiO2/PAC) for Removal and Photocatalytic Properties of 2-Methylisoborneol (2-MIB) in Water

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1622
Author(s):  
Xiao-Pin Guo ◽  
Peng Zang ◽  
Yong-Mei Li ◽  
Dong-Su Bi
Keyword(s):  
Activated Carbon ◽  
Natural Organic Matter ◽  
Uv Light ◽  
Sol Gel ◽  
Light Irradiation ◽  
Nano Tio2 ◽  
Uv Light Irradiation ◽  
Adsorption Capacities ◽  
Taste And Odor ◽  
Composite Photocatalysts

2-methylisoborneol (2-MIB) is a common taste and odor compound caused by off-flavor secondary metabolites, which represents one of the greatest challenges for drinking water utilities worldwide. A TiO2-coated activated carbon (TiO2/PAC) has been synthesized using the sol-gel method. A new TiO2/PAC photocatalyst has been successfully employed in photodegradation of 2-MIB under UV light irradiation. In addition, the combined results of XRD, SEM-EDX, FTIR and UV-Vis suggested that the nano-TiO2 had been successfully loaded on the surface of PAC. Experimental results of 2-MIB removal indicated that the adsorption capacities of PAC for 2-MIB were higher than that of TiO2/PAC. However, in the natural organic matter (NOM) bearing water, the removal efficiency of 2-MIB by TiO2/PAC and PAC were 97.8% and 65.4%, respectively, under UV light irradiation. Moreover, it was shown that the presence of NOMs had a distinct effect on the removal of MIB by TiO2/PAC and PAC. In addition, a simplified equivalent background compound (SEBC) model could not only be used to describe the competitive adsorption of MIB and NOM, but also represent the photocatalytic process. In comparison to other related studies, there are a few novel composite photocatalysts that could efficiently and rapidly remove MIB by the combination of adsorption and photocatalysis.

Photocatalytic performance of Cu-doped titania thin films under UV light irradiation

2021 ◽  
Vol 553 ◽  
pp. 149535
Author(s):  
Elisa Moretti ◽  
Elti Cattaruzza ◽  
Cristina Flora ◽  
Aldo Talon ◽  
Eugenio Casini ◽  
...  
Keyword(s):  
Thin Films ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Light Irradiation ◽  
Uv Light Irradiation ◽  
Doped Titania
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