Novel I-BiOBr/BiPO4 heterostructure: synergetic effects of I− ion doping and the electron trapping role of wide-band-gap BiPO4 nanorods

Abstract

A novel I⁻-doped BiOBr/BiPO₄ (I-BiOBr/BiPO₄) heterostructure was constructed by a facile deposition-precipitation method using wide-band-gap BiPO₄ nanorods as the substrate. The as-prepared I-BiOBr/BiPO₄ composite exhibited a notably enhanced photocatalytic performance in the decomposing of methyl orange and phenol under visible light (λ > 420 nm) irradiation in comparison with BiOBr, I-BiOBr, BiPO₄ and BiOBr/BiPO₄ reference samples. The photocatalytic activity improvement of I-BiOBr/BiPO₄ mainly resulted from the synergetic effects of doped I⁻ ions in I-BiOBr and the heterojunction interface between I-BiOBr and BiPO₄. I⁻ ions doping narrowed the band-gap energy of BiOBr to generate more photocharges under visible light irradiation. Moreover, BiPO₄ quickly trapped and transferred the electrons originating from I-BiOBr. This study affords a facile strategy to intensively improve the visible light photocatalytic activity of the BiOX system for water contaminants removal.