▎ 摘　　要

A novel 3D bismuth 3D-BiOClxBr1-x/GO heterojunction with excellent visible light activity was synthesized by doping graphene oxide (GO) in as-prepared 3D-BiOCl0.5Br0.5 via a facile hydrothermal method. The synthesized 3D-BiOCl0.5Br0.5/GO heterojunction exhibited a hierarchical globose corolla-like nanoscale structure with a large surface area and a suitable pore size. GO doping was favorable for forming a chemical bond between GO and bismuth oxyhalide. Introducing a small amount of GO sheets into 3D-BiOCl0.5Br0.5 can improve the surface chemical structure of 3D-BiOCl0.5Br0.5, increase surface adsorption sites, accelerate electron transmission and avoid e(-) and h(+) recombination. In this way, the adsorption and degradation capacities of 3D-BiOCl0.5Br0.5/GO to formaldehyde were significantly enhanced. Under visible light irradiation, the synthesized samples demonstrated advanced photocatalytic capacities for formaldehyde degradation when compared with pure 3D-BiOCl0.5Br0.5, indicating synergistic enhancement effects between GO and 3D BiOCl0.5Br0.5. The efficiency of the 3D-BiOCl0.5Br0.5/GO heterojunction for formaldehyde degradation was over 89.6% within 120 min at room temperature, which shows promise for effectively treating environmental pollution caused by indoor aldehyde emissions. Enhanced photocatalytic activity mechanisms of the 3D-BiOCl0.5Br0.5/GO heterojunction were proposed based on experimental findings. (C) 2019 Elsevier B.V. All rights reserved.