Novel 2D/2D BiOBr/Zn(OH)2 photocatalysts for efficient photoreduction CO2

•The heterostructural 2D/2D BiOBr/Zn(OH)2 composite was prepared by direct precipitation polymerization.•The composite displays more effective charge separation and migration.•The composite presents a high CO production of 16.21 μmol g−1. For the sake of enhancing the photocatalytic performance of BiOBr, 2D Zn(OH)2 nanosheets were introduced on 2D BiOBr nanosheets to construct a 2D heterosturcture in BiOBr/Zn(OH)2 composites by direct precipitation polymerization. After depositing Zn(OH)2, the specific surface areas of BiOBr/Zn(OH)2 composites were improved, which resulted in more active sites. Meanwhile, the synergistic action between Zn(OH)2 and BiOBr can adjust the band-gap, enhancing the light absorption and reducing the charge transfer resistance. BiOBr/Zn(OH)2 composites possessed the better separation efficiency of photogenerated carriers. Meanwhile, the results showed that the ability of photocatalytic CO2 reduction was improved. Under 3 h simulated sunlight irradiation, BiOBr/Zn(OH)2–10% showed the highest performance of photocatalytic CO2 reduction, and the total output of photocatalytic reduction product CO was 16.21 μmol g−1, which is 2.2 times than that of BiOBr.