Modeling and predicting the photodecomposition of methylene blue via ZnO–SnO2 hybrids using design of experiments (DOE)

2023

Appl Water Sci

The main goal of the present research is the synthesis of new photocatalysts to reduce the amount of organic pollutants in aquatic environments. For this purpose, the amount of TiO2 nanoparticles in the synthesized samples containing MWCNTs is controlled to synthesize two types of photocatalysts named as MCT#1 and MCT#2. Samples characterizing using XRD reveal that the TiO2 nanoparticles have a combined phase of rutile and anatase. So that in both of photocatalysts, the percentage of anatase phase is higher than rutile. The analysis of the degradation rate demonstrates that intensification level of TiO2 nanoparticles in MCT#2 compared to the MCT#1 leads to enhancement of photocatalytic activity of MCT#2. Design of experiment results shows that the destruction amount of MO is affected by irradiation time and pH. Based on ANOVA study, it is observed that both factors have a significant effect on reducing of MO concentration. Analyzing the results based on Duncan's multiple range test at α = 0.05 confirm that all the studied levels of the main parameters have a logical influence on MO destruction. Meanwhile, it can be deducted that the most and the least of destruction is observed at pH = 7 and pH = 3, respectively.

“…Finally, the amount of destruction rate of the MO using synthesized MCT#1 and MCT#2 is calculated using the Eq. 1 (Abbasi s et al 2019;Abbasi et al 2017b):…”

Section: Evaluation Of Contaminant Removal Efficiency Using Mct#1 And...mentioning

confidence: 99%

Studying the destruction of pollutant in the presence of photocatalysts based on MWCNTs with controlled values of TiO2 nanoparticles

2023

Appl Water Sci

“…The reduction of MO concentration with enhancement of the applied photocatalysts concentration (MCT#1 and MCT#2) is due to the augmentation of the contact surface of the photocatalysts with UV irradiation and organic pollutants. The enhancement of the contact surface leads to the increasing of the exited electrons and the created e --h + pairs [7,9,11]. Therefore, the enhancement of the photocatalysts weight fraction has a positive effect on the decomposition rate of MO.…”

Section: Tem Studymentioning

confidence: 99%

“…The UV irradiation leads to the excitation of electrons that are located in the valence band of the semiconductors. The excited electrons can transmit from the valence band to the conduction band [7,8]. Therefore, due to the migration of an electron from the valence layer to the conduction layer, a hole and an electron are produced on the valence band and conduction band, respectively.…”

Section: Introductionmentioning

confidence: 99%

The Dependence of Photocatalytic Activity on Tio2 to MWCNT Ratio in the Composite

2021

Preprint

Self Cite

Here, we prepared two kinds of nanocomposites (MCT#1 and MCT#2) involving MWCNTs and TiO2 nanopaerticles. The characterization of the samples is carried out based on FTIR spectroscopy and TEM. The Ti-O groups that is attibuted to the TiO2 nanopaerticles can be confirmed according to the FTIR analysis. TEM images show that the average particle size of TiO2 nanopaerticles in prepare MCT#1 and MCT#2 is equal to 13 nm and 15 nm, respectively. The influence of nanocomposites weight fraction and illumination time are investigated on the decomposition rate of methyl orange (MO) as pollutant. The photocatalytic results exhibit that the decomposition rate of MO is increased with respect to the weight fraction and illumination time. Meanwhile, higher decomposition rate can be observed using MCT#2 compared to MCT#1. Statistical analysis of the results based on Duncan’s multiple range test at α = 0.05 reveals that all of the applied levels of the factors have a significant effect on the decomposition rate. The response surface results confirm that the effect of illumination time is high that that of weight fraction of MCT#1 and MCT#2.

“…The application of semiconductor photocatalysts is a new approach for decomposition of organic pollutants [1,2]. In this technique, a light source with energy higher than the band gap of used semiconductors is applied [3]. The irradiation of the semiconductors leads to the migration of electrons that are located in the valence band to the conduction band.…”

Section: Introductionmentioning

confidence: 99%

Improvement of photocatalytic decomposition of methyl orange by modified MWCNTs, prediction of degradation rate using statistical models

J Mater Sci: Mater Electron

2021

Self Cite

Multi-walled carbon nanotubes (MWCNTs) have been successfully modi ed with TiO2 nanoparticles via a two-step hydrolysis technique. Firstly, the pristine MWCNTs are functionalized in nitric acid (HNO3) to creation of oxygen containing groups. Secondly, TiO2 nanoparticles are synthesized on the surface of functionalized MWCNTs through hydrolysis method. The synthesized samples have been used as photocatalyst for decomposition of methyl orange (MO) as dye organic pollutant. The characterization of samples using x-ray diffraction pattern (XRD) con rm the presence of TiO2 nanoparticles with mixture of anatase and rutile phases. Regarding the photocatalytic performance of TiO2 nanoparticles and modi ed MWCNTs with TiO2 nanoparticles, it observed that the degradation rate of MO increases by increasing the irradiation time from 5 min to 35 min. The variation of degradation rate upon pH of suspension reveals that the maximum and minimum degradation rate are in acidic (pH=3) and neutral condition (pH=7). Meanwhile, the results show that the presence of MWCNTs leads to the enhancement of degradation rate. The analysis of variance (ANOVA) results con rm that both of main factors (irradiation time and pH) and their interaction have a signi cant in uence on the degradation rate of MO. However, the effect of irradiation time is more than that of pH and their interaction. The graphical methods verify the quality and adequacy of the statistical models for prediction of the degradation rate.