Visible-light responsive ZnSe-anchored mesoporous TiO2 heterostructures for boosted photocatalytic reduction of Cr(VI)

Abstract

Abstract The accumulation of Cr(VI) ions in water can cause serious influences on the environment and human health. This work reports a humble synthesis of ZnSe nanoparticles anchored to the sol-gel prepared TiO2 for visible-light-driven photocatalytic reduction of Cr(VI) ions. The 7.9 nm ZnSe nanoparticles were attached to TiO2 surfaces at a content of 1.0−4.0 wt% as experiential by TEM investigation. The designed nanocomposite unveiled mesostructured surfaces exhibiting surface areas of 176−210 m2 g−1. The impregnation of ZnSe amended the visible-light absorption of TiO2 due to the bandgap decrease from 3.14 to 2.90 eV. The photocatalytic reduction of Cr(VI) applying the optimized portion of 3.0 wt% ZnSe/TiO2 was achieved at 177 μmol min−1. This photocatalytic activity is higher than the common Degussa P25 and pristine TiO2 by 20 and 30 times, respectively. The improved performance is signified by the efficient interfacial separation of charge carriers by the introduction of ZnSe. This innovative ZnSe/TiO2 has also shown photocatalytic stability for five consecutive runs.