Charge separation properties of (BiO)2CO3/BiOI heterostructures with enhanced solar-driven photocatalytic activity

• The absorbance of composites increases and appears red-shift.
• The photo-induced charge separation rate has been enhanced.
• The photocatalytic activity has been greatly promoted.

(BiO)2CO3/BiOI heterojunctions were prepared in-situ by a pore impregnating method using HI aqueous solution. The specific surface area, structure, morphology, and charge separation properties of the heterostructures prepared were characterized by Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), scanning electron microscopy (SEM), and surface photovoltage (SPV) spectroscopy, respectively. The active species were investigated using scavengers. The photocatalytic activities of (BiO)2CO3/BiOI heterojunctions towards discoloration of rhodamine B (RhB) under simulated sun light irradiation were evaluated. Benefiting from enhanced charge separation efficiency, the composite photocatalysts exhibit higher photocatalytic performance than the pure BiOI. Finally, the possible reason was discussed.