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Novel BiOI/I-(BiO)2CO3 composite was constructed for the first time.

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BiOI/I-(BiO)2CO3 displayed excellent activity for MO and phenol removal.

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BiOI/I-(BiO)2CO3 exhibited enhanced separation efficiency of photocharges.

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Doping and heterojunction cooperatively facilitated activity enhancement.

Abstract 

The wide-band-gap semiconductor (BiO)2CO3 was modified by interior doping with I− ions and surface loading with BiOI to prepare a highly efficient visible-light active photocatalyst for the degradation of methyl orange and phenol. The interior I− ions elevate the valence band position of (BiO)2CO3 and induce visible-light photocatalytic activity, while the in-situ-formed BiOI/I-(BiO)2CO3 heterojunction significantly improves the separation of photoinduced charge carriers. By the action of the reactive species h+ and O2−, methyl orange and phenol were degraded over the novel BiOI/I-(BiO)2CO3 composite at rates that were 18- and 4-times, respectively, those of unmodified (BiO)2CO3. Thus, the findings presented here may be widely applied in the development of wide-band-gap semiconductor photocatalytic systems for the highly efficient removal of contaminants from wastewater.

Experimental

Photocaalytic activity measurements

    solutions were used to evaluate the photocatalytic activities of the samples. In the experiements, 0.10g of the photocatalyst was dispersed in 50ml of MO solytion(10 mg/L) and stirred magnetically for 30 min in the dark to reach addsorption- desporption equilibrium. The suspensioin was then irradiated in a photoreaction apparatus with a 300 W Xe lamp(PE300BFA, 300W. Beijing China Education Au-light Co., Ltd.)