Vertical grown BiOI nanosheets on TiO2 NTs/Ti meshes toward enhanced photocatalytic performances

Abstract

Vertical grown BiOI nanosheets were fabricated by the solvothermal deposition on the surface of TiO2 nanotube arrays (TiO2 NTs)/Ti meshes for the enhanced photocatalytic removal of organic dyes and heavy metal ions. The BiOI nanosheets with different size and distribution were prepared by changing the reagent concentration. The photoelectrochemical results illustrated that the TiO2 NTs/BiOI (0.05) prepared with Bi3+ concentration of 0.05 mol/L showed the uniform nanosheet structure, strong solar absorption, high photocurrent generation, low interface resistance and outstanding photocatalytic property. The visible light photocurrent and photovoltage achieved 114.33 μA/cm2 and -0.24 V, and the photocatalytic removal efficiencies of MO, RhB, MB and Cr (VI) achieved 92.22%, 97.28%, 96.57% and 70.51%, respectively. Moreover, the photocatalytic stability, active group and electron transfer mechanism were also investigated. The TiO2 NTs/BiOI heterojunction provided the effective charge carrier transportation path, which dramatically inhibited the combination and consumption of electrons. The design and construction of TiO2 NTs/BiOI electrodes identified the strategy for the efficient photocatalytic pollution treatment.