Ti₂O₇: An efficient and stable photocatalyst for the photoreduction of Cr(VI) ions in water

In the present work, the photocatalytic activity of La₂Ti₂O₇ for the photoreduction of Cr(VI) ions in water was investigated. The results indicated that La₂Ti₂O₇ is an efficient photocatalyst with 98% of reduction efficiency of Cr(VI) ions after 3h ultraviolet (UV) irradiation. Meanwhile, the stability of La₂Ti₂O₇ in the photocatalysis was investigated by repeatedly performing Cr(VI) photoreducing experiments. It can be found that the photocatalytic activity of La₂Ti₂O₇ remained almost unchanged after nine successive cycles, and the reduction ratio of Cr(VI) ions was still up to 50% in the twentieth cycle. Furthermore, for practical purposes, the photocatalytic reduction of Cr(VI) ions was studied as functions of the solution pH, initial Cr(VI) concentration and additional salts.