Preparation, photocatalytic activity, and mechanism of Cd2Sb2O6.8-graphene composite

• Cd2Sb2O6.8-GR nanocomposite performs high photocatalytic activity.
• Graphene plays an important role in the enhancement of its photocatalytic activity.
• The role of GR was carefully verified and a possible mechanism on samples are proposed for the first time.
• Our research presents a new idea for the design of efficient composite photocatalyst.

Novel nanocomposite materials, based on graphene (GR) and Cd2Sb2O6.8, were synthesized successfully through a facial one-step hydrothermal method for the first time. Characterized by X-ray diffraction, UV–vis diffuse reflectance spectroscopy, transmission electron microscopy, field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy, Raman spectroscopy, etc., it demonstrated that Cd2Sb2O6.8 nanoparticles were effectively anchored in GR sheets. By the degradation of rhodamine B (RhB) and methylene blue, such Cd2Sb2O6.8-GR nanocomposites exhibited a much higher photocatalytic activity than the pure Cd2Sb2O6.8. Especially, when the mass ratio of GR in Cd2Sb2O6.8-GR nanocomposite was 2% (labeled as Cd2Sb2O6.8-2%GR), it possessed the optimal photocatalytic ability on the degradation of RhB which was as high as that of commercial P25. It was proved that GR played an important role in the enhancement of photocatalytic performance of composites. Which give a good chance to make an effective charge separation and generation of multifarious reactive species, such as OH, O2−, h+, e−. A possible mechanism of the degradation process was carefully discussed. This work provided a new insight into the photocatalytic degradation of dyes under UV irradiation and opens up a new prospect to Cd2Sb2O6.8-GR photocatalysts.

In this work, Cd2Sb2O6.8-GR nanocomposite photocatalyst was prepared through a facial one-step method. Which exhibited obviously high photocatalytic activity in the degradation of organic pollutants. The role of graphene was carefully verified and a possible mechanism for degradation of organic pollutants on Cd2Sb2O6.8-GR were proposed and discussed in detail.Figure optionsDownload as PowerPoint slide