Background
Type: Article

Photocatalytic degradation and adsorption of herbicide 2,4-dichlorophenoxyacetic acid from aqueous solution using TiO2/BiOBr/Bi2S3 nanostructure stabilized on the activated carbon under visible light

Journal: Environmental Nanotechnology, Monitoring and Management (22151532)Year: May 2021Volume: 15Issue:
DOI:10.1016/j.enmm.2020.100415Language: English

Abstract

TiO2/BiOBr/Bi2S3 nanostructure impregnated on the activated carbon (AC) was synthesized, in order to achieve considerable synergy between photocatalysis and adsorption for 2,4-dichlorophenoxyacetic acid (2,4-D) removal from polluted water. The XRD, XRF, EDX, FE-SEM, and FT-IR analyses confirmed successful formation of the catalyst. The results of UV-DRS analysis, showed the estimated band gaps obtained were about 2.8 eV and 2.55 eV for the TiO2/BiOBr and TiO2/BiOBr/Bi2S3 nanostructures respectively showing high potential for the wide range of visible and solar spectrum. The photocatalytic degradation results based on the response surface methodology (RSM) experimental design confirmed that initial 2,4-D concentration, pH, catalyst concentration, irradiation time and the interaction between TiO2/BiOBr/Bi2S3/AC concentration and irradiation time had the most effects, respectively. The best results were obtained under the optimum conditions (2,4-D = 90 mg/L, pH = 3, catalyst = 0.6 mg/L and irradiation time = 90 min) on which the pollutant removal efficiency was 98 % and TOC removal efficiency was determined 74 %. Increasing the visible light intensity to 120 mW/cm2 resulted in a complete degradation. The coexistence of 10 % BiOBr and 5%Bi2S3 compounds on TiO2 not only increased the absorption edge to 600 nm and charge transportation but also improved photocatalytic properties of TiO2/BiOBr/Bi2S3/AC nanostructure as it could be an appropriate compound for water treatment. © 2020 Elsevier B.V.


Author Keywords

2,4-dichlorophenoxyacetic acidAdsorptionHeterojunction catalystPhotocatalytic degradationTiO2/BiOBr/Bi2S3/ACVisible light