Enhanced photocatalytic activity of anatase by the rational modification of the {001} facets with Fe(iii) ions

Abstract

Anatase nanosheets (ANs) with a high percentage of the {001} facets are considered good photocatalysts due to the higher energy of these facets as compared to that of the {101} facets. Accordingly, it is important to overcome the drawback of decreasing the electron transport deficiency without varying the morphology of the catalysts. In order to solve this issue, herein, the rational modification of ANs by Fe(III) was proven to be a feasible approach. A series of metal ions (Mn, Fe, Co, Ni, and Cu) are used to support the feasibility of this rational design. As result, Fe(III)-modified ANs (Fe-0.5-TiO₂) present excellent activity for the decomposition of dye molecules and p-chlorophenol compared to the other samples and the commercial P25 catalyst under simulated solar-light irradiation (200 mW cm⁻²). It is proposed that the Fe(III) ions bind electrons and form Fe³⁺/Fe²⁺ redox couples on the surface of ANs, which have a lower potential than the conduction band of TiO₂. Thus ˙O₂⁻ is more easily generated. The Fe(III) species are attributed as the electron-trapping centers and enhance the efficiency of electron transport in TiO₂.