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

Abstract

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.

Catalytic performance of ZnO-Ce nanoparticles decorated on biochar derived from Milkvetch for photocatalytic removal of reactive blue 19 dye

“…The heterogeneous photocatalytic advanced oxidation process is an approach in which a strong oxidant such as hydrogen peroxide or ozone and a catalyst containing zinc oxide, iron, and manganese are used in the presence or absence of an ultraviolet radiation source [11,12]. These procedures are based on the formation of free hydroxyl radicals with high oxidizing power, which cause the conversion of organic chemical pollutants into inorganic substances that are most effective in oxidizing organic compounds [13,14]. When the energy of a photon is equal to or greater than the energy gap (Eg) of the semiconductor, excitation of the electron from the valence band to the conduction band occurs, and the excitation of the electron creates a hole in the valence band [15].…”