Photodegradation of 2,4-D over PdO/Al2O3–Nd2O3 photocatalysts prepared by the sol–gel method

The photocatalytic activity of 1.0 wt% PdO supported on Al2O3–Nd2O3 binary oxides prepared by the sol–gel method was studied in the photodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D). The photocatalysts were characterized by N2 physisorption, XRD and UV–vis spectroscopy. PdO supported on γ-Al2O3 photo-degrades the 2,4-D, however the addition of Nd2O3 to γ-Al2O3 notably improves the photocatalytic activity. As the concentration of Nd2O3 in the binary oxide increases from 2 to 10 wt%, the photodegradation of 2,4-D is highly enhanced. The catalytic test for PdO supported on pure Nd2O3 showed scarce photocatalytic activity. Total organic carbon (TOC) analysis showed that the 2,4-D has been completely destroyed on the PdO/Al2O3–Nd2O3 photocatalysts after 6 h under irradiation.