Adsorption and photodegradation kinetics of herbicide 2,4,5-trichlorophenoxyacetic acid with MgFeTi layered double hydroxides

• Calcined LDHs (MgFe and MgFeTi) were synthesized by co-precipitation method.
• The developed LDHs showed excellent photo-Fenton-like degradation of 2,4,5-T.
• The mechanisms for adsorption and photodegradation of 2,4,5-T are proposed.
• A green, low cost and high efficiency photocatalyst for environmental remediation.

The calcined layered double hydroxides (cLDHs) Ti-doped and undoped MgFe for this study were prepared by co-precipitation method followed by calcination at 500 °C. The as-prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) and UV–Vis diffuse reflectance spectrum (DRS) techniques and tested for adsorption and photodegradation (including photocatalytic and photo-Fenton-like) of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in aqueous solutions under visible light irradiation. In the range of studied operating conditions, the as-prepared samples exhibited excellent photo-Fenton-like activity, leading to more than 80–95% degradation of 2,4,5-T at initial concentration of 100 mg L−1 with 4 g calcined LDHs per liter, was accomplished in 360 min, while 2,4,5-T half-life time was as short as 99–182 min. The kinetics of adsorption and photodegradation of 2,4,5-T were also discussed. These results offered a green, low cost and high efficiency photocatalyst for environmental remediation.

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