Two kinds of Fe-containing pillared bentonites were used as heterogeneous photocatalysts. Structural characteristics were examined by using XRD, BET and TEM. Results indicate that both catalysts have large surface areas and iron element is in the form of α-Fe₂O₃ of high catalytic activity. The photocatalytic activities of the photocatalysts were determined by the photo-assisted degradation of an organic azo dye methyl orange, and the influence of different types of catalysts, their amounts and the H₂O₂ concentration were also investigated. Experimental results show that two kinds of heterogeneous photocatalysts both have high catalytic activities of decoloration and COD_Cr removal. Degradation ratios of two photocatalysts have predominance compared with those of homogeneous Fenton reactions, respectively. The photocatalytic activity of Fe-Al-Bent is superior to that of Fe-Bent because of its larger surface area and higher acidity. In addition, our experiments also illustrate that Fe-Al-Bent can be easily recovered, regenerated and reused.

Key words: pillared clay, heterogeneous photocatalyst, photocatalytic degradation, methyl orang