A facile approach to construct BiOI/Bi₅O₇I composites with heterostructures: Efficient charge separation and enhanced photocatalytic activity

A series of BiOI/Bi₅O₇I composite photocatalysts with heterostructures was successfully synthetized through a facile hydrothermal method. Attributed to the heterostructure between BiOI and Bi₅O₇I, photogenerated electrons and holes can be separated efficiently. The photocatalytic activity of the as-prepared samples was evaluated through the MO degradation reaction. The removal rate of MO was up to 93% after 40 min under visible light (λ ≥ 400 nm) irradiation, while the photocatalytic activity showed no decay after 3 cycles. Furthermore, the photocatalytic mechanism of MO degradation over the BiOI/Bi₅O₇I composite photocatalyst was investigated by taking TA, H₂O₂ and EDTA as probes. The experimental results indicate that the enhanced photocatalytic performance is attributed to the synergistic effect of photogenerated holes and superoxide radicals. The excellent activity and photostability reveal that the BiOI/Bi₅O₇I composite photocatalyst is a promising visible-light-response photocatalyst with potential applications in the field of water treatment.