scholarly journals Photocatalytic degradation as Davidson–Cole relaxation in time domain

2019 ◽  
Vol 09 (01) ◽  
pp. 1950006 ◽  
Author(s):  
C. L. WANG
Keyword(s):  
Experimental Data ◽  
Differential Equations ◽  
Photocatalytic Degradation ◽  
Gamma Function ◽  
Time Domain ◽  
Degradation Kinetics ◽  
Incomplete Gamma Function ◽  
Response Functions ◽  
Degradation Processes

Photocatalytic degradation processes of different materials are fitted with Mittag-Leffler function and incomplete gamma function, which are response functions for Cole–Cole relaxation and Davidson–Cole relaxation. The fitting results show that both functions can fit experimental data fairly well. The order of derivative in the kinetic differential equations can be either less, or greater than one. In the case of the order of derivative is greater than one, only incomplete gamma function is reasonable for describing the photocatalytic degradation. This work further confirms the existence of the universality in photocatalytic degradation kinetics.

scholarly journals Photocatalytic degradations of JWS-type kinetics

2021 ◽  
Author(s):  
C. L. Wang
Keyword(s):  
Experimental Data ◽  
Fractional Calculus ◽  
Photocatalytic Degradation ◽  
Chemical Kinetics ◽  
Relaxation Function ◽  
Degradation Kinetics ◽  
Material Parameters ◽  
Kinetics Of ◽  
Fitting Parameters

Photocatalytic degradation kinetics of Jurlewicz–Weron–Stanislavsky (JWS) type has been identified. Experimental data are taken from previous published works, and fitted with the JWS relaxation function as well as that of the Havriliak–Negami (HN) model. All experimental data can fit with either model fairly good. From the fitting parameters, the Jonscher indices are calculated and Jonscher diagram is plotted for the chemical kinetics of photocatalytic degradations. This work suggests that material parameters of photocatalysts can be well defined in the sense of fractional calculus.

ON THE INCOMPLETE GAMMA FUNCTION AND ITS NEUTRIX CONVOLUTION FOR NEGATIVE INTEGERS

2019 ◽  
Vol 10 (1) ◽  
pp. 30-51
Author(s):  
Mongkolsery Lin ◽  
◽  
Brian Fisher ◽  
Somsak Orankitjaroen ◽  
◽  
...  
Keyword(s):  
Gamma Function ◽  
Incomplete Gamma Function

Study of Photocatalytic Dergradation, Kinetics and Microbial Activities of Copper (ii) Soya Urea Complex in Non Aqueous Media

2020 ◽  
Vol 17 ◽  
Author(s):  
Vandana Sukhadia ◽  
Rashmi Sharma ◽  
Asha Meena
Keyword(s):  
Staphylococcus Aureus ◽  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Waste Water Treatment ◽  
Aqueous Media ◽  
Research Work ◽  
Solvent Polarity ◽  
Urea Complex ◽  
Pseudo First Order Reaction ◽  
Aqueous Solvent

Aims: The aim of this research work is to synthesise, study and analyse photocatalytic degradation, kinetics and microbial activity of new surfactant Copper (II) soya urea complex(CSU). Background: Photocatalytic degradation has attracted the attention of scientific community throughout the world due to its multiple applications in environment, energy, waste water treatment, pollution control, green chemistry, etc. Copper (II) soya urea complex has been synthesized and characterized through FT-IR, NMR, ESR studies. Objective: Present work deals with the study of photocatalytic degradation of Copper (II) soya urea complex by using ZnO as semiconductor. This study employs a semiconductor catalyst using non polar and non aqueous solvent in photocatalytic degradation. Reaction rate is chosen as the photocatalytic activity, which has been governed by several factors. Antibacterial activities of Copper (II) complex have also been studied against Staphylococcus aureus. Method: Optical density (O.D.) was measured after different time intervals spectrophotometrically to measure the degradation of complex. Mueller-Hinton agar medium was used for antimicrobial activity of synthesized compound at different concentrations by disk/ well diffusion susceptibility testing. Result: Plot of 2+log O.D. (absorbance) versus time was plotted and found linear. The heterogeneous photocatalysis followed pseudo-first-order reaction kinetics.The present study suggests that Copper (II) soya urea (CSU) complex shows antibacterial activity against Staphylococcus aureus at different concentrations. Conclusion: The results were used to determine the rate of photocatalytic degradation of CSU complex .It has been found that rate of degradation varies with different parameters like concentration of complex, amount of catalyst, light intensity, solvent polarity etc. CSU complex derived from soyabean oil has been shown an inhibitory effect on the growth of S. aureus which may causes skin disease.

Photocatalytic Degradation and Antibacterial Study of Copper(II) Mustard Thiourea Complex

2020 ◽  
Vol 10 (3) ◽  
pp. 229-242
Author(s):  
Vandana Sukhadia ◽  
Rashmi Sharma ◽  
Asha Meena
Keyword(s):  
Photocatalytic Degradation ◽  
Skin Diseases ◽  
Polar Solvent ◽  
Degradation Kinetics ◽  
Research Work ◽  
Solvent Polarity ◽  
Inhibitory Effect ◽  
Mustard Oil ◽  
Urea Complex ◽  
Pseudo First Order Reaction

Aims: The aim of this research work is to synthesise, study and analyse photocatalytic degradation, kinetics. Background: Copper(II) mustard thio urea complex has been synthesized and characterized through FT-IR, NMR, ESR studies. Objective: Photocatalytic degradation of copper(II) mustard thio urea complex was studied in the presence of ZnO as a catalyst in the solution form, using a non polar solvent benzene and a polar solvent methanol with different compositions. Antibacterial activities of copper(II) complex have also been studied against Staphylococcus aureus. Method: O.D. was measured after different time intervals spectrophotometrically to measure the degradation of the complex. Result: Plot of 2+ log O.D. (absorbance) versus time was plotted and found to be linear. The heterogeneous photocatalysis followed pseudo-first-order reaction kinetics. The present study suggests that the CMT complex shows antibacterial activity at different concentrations. Conclusion: The rate of photocatalytic degradation of CMT complex was studied and analyzed. It has been found that the rate of degradation varies with different parameters like the concentration of complex, the amount of catalyst, light intensity, solvent polarity etc. The CMT complex derived from natural mustard oil has shown an inhibitory effect on the growth of S. aureus which may cause skin diseases.

scholarly journals Kinetic Modeling and Degradation Study of Liquid Polysulfide Resin-Clay Nanocomposite

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 635
Author(s):  
Mohamadreza Shakiba ◽  
Arash Kakoei ◽  
Iman Jafari ◽  
Erfan Rezvani Ghomi ◽  
Mohammadreza Kalaee ◽  
...  
Keyword(s):  
Experimental Data ◽  
Kinetic Modeling ◽  
Degradation Kinetics ◽  
Nitrogen Atmosphere ◽  
Gravimetric Analysis ◽  
Degradation Kinetic ◽  
Kinetic Evaluation ◽  
Degradation Study ◽  
Clay Nanoparticles ◽  
Conversion Rates

Kinetic modeling and degradation study of liquid polysulfide (LPS)/clay nanocomposite is possible through Ozawa–Flynn–Wall (OFW) and Kissinger methods. Comparing the results of these models with experimental data leads to provide an accurate degradation kinetic evaluation of these materials. To this aim, the morphology and distribution of clay nanoparticles (CNPs) within the LPS matrix were investigated using Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffraction (XRD). To evaluate the interaction between the LPS and the CNPs, the Fourier transform infrared (FTIR) identification was utilized. Furthermore, to investigate the kinetics of degradation, the thermal gravimetric analysis (TGA) and derivative thermogravimetry (DTG) of the samples were used in the nitrogen atmosphere with the help of Kissinger and Ozawa–Flynn–Wall (OFW) models. The characterization results confirmed the homogenous dispersion of the CNPs into the LPS matrix. In addition, the presence of CNPs increased the thermal stability and activation energy (Ea) of the samples at different conversion rates. Moreover, the OFW method was highly consistent with the experimental data and provided an appropriate fit for the degradation kinetics.

Immobilization of Nano-TiO2 on Expanded Perlite for Photocatalytic Degradation of Rhodamine B

2011 ◽  
Vol 110-116 ◽  
pp. 3795-3800 ◽  
Author(s):  
Xiao Zhi Wang ◽  
Wei Wei Yong ◽  
Wei Qin Yin ◽  
Ke Feng ◽  
Rong Guo
Keyword(s):  
Catalytic Activity ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Degradation Kinetics ◽  
Irradiation Time ◽  
Sol Gel ◽  
Polluted Water ◽  
Order Kinetic ◽  
Expanded Perlite ◽  
Initial Concentration

Expanded perlite (EP) modified titanium dioxide (TiO2) with different loading times were prepared by Sol-Gel method. Photocatalytic degradation kinetics of Rhodamine B (RhB) in polluted water by the materials (EP-nanoTiO2), as well as the effects of different loading times and the initial concentration of RhB on photocatalysis rate were examined. The catalytic activity of the regenerated photocatalyst was also tested. The results showed that photocatalyst modified three times with TiO2had the highest catalytic activity. Degradation ratio of RhB by EP-nanoTiO2(modified three times) under irradiation for 6 h were 98.0%, 75.6% and 63.2% for 10 mg/L, 20 mg/L and 30 mg/L, respectively.The photocatalyst activity has little change after the five times recycling, and the degradation rate of RhB decreased less than 8%. The reaction of photocatalysis for RhB with irradiation time can be expressed as first-order kinetic mode within the initial concentration range of RhB between 10mg/L and 30 mg/L. EP-nanoTiO2photocatalyst has a higher activity and stability to degrade RhB in aqueous solution.

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