Fabrication of flower-like BiOI/Bi5O7I heterojunction photocatalyst by pH adjustment method for enhancing photocatalytic performance

The flower-like BiOI/Bi5O7I heterojunction photocatalysts were prepared by a pH adjustment method, and the photocatalytic oxidation activity of the as-prepared samples was investigated by gas-phase Hg-0 removal. XRD, SEM, TEM, UV-vis, and PL characterization analysis method were adopted to evaluate the physicochemical property of samples. It was found that the sample showed an excellent photocatalytic performance for mercury removal when the pH of the sample fabrication arrived at 10.0. It can be attributed to the formation of an interfacial heterojunction between BiOI and Bi5O7I, which inhibits the recombination of electrons and holes. A possible photocatalytic reaction mechanism for the oxidation of Hg-0 has also been proposed. (C) 2019 Elsevier B.V. All rights reserved.