Photocatalytic degradation of 2,4-D and 2,4-DP herbicides on Pt/TiO2 nanoparticles

Abstract

Titanium dioxide was synthesized by the sol–gel method and platinum supported on titanium dioxide were prepared by a wet impregnation chemical process at different platinum contents. The prepared samples were dried over night at 110°C and then calcined at 500°C for 4h. Structural and morphological characterization has been carried out by means of X-ray diffraction (XRD), differential scanning calorimetry–thermogravimetric analysis (DSC–TGA), Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller surface area measurement (BET) and transmission electron microscopy coupled to the energy dispersive spectroscopy (TEM/EDX). The adsorption performance and photocatalytic activity of the samples were investigated using two chlorophenoxy herbicides: 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-(2,4-dichlorophenoxy) propionic acid (2,4-DP) as models of organic pollutants in water. The obtained results show that Pt/TiO2 exhibited higher photocatalytic activity than TiO2 particles for the degradation of the two selected herbicides. The photocatalytic activity increases by increasing the platinum yield in the catalyst.