Synthesis and Photocatalytic Activity of Z-Scheme Photocatalyst Sb2WO6/g-C3N4

Sb2WO6 modified g-C3N4 (Sb2WO6/g-C3N4) composites were synthesized by hydrothermal reaction. The properties of the Sb2WO6/g-C3N4 composites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) , UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and photoluminescence( PL) spectroscopy. The results indicated that the Sb2WO6 grew on the surface of g-C3N4, forming closely contacted interfaces between the Sb2WO6 and g-C3N4 components. The photocatalytic performance of Sb2WO6/g-C3N4 composites was evaluated through the photodegradation of Rhodamine B (RhB). The results showed that 99. 3% of RhB was degraded by Sb2WO6/g-C3N4 composites with 10% (mass fraction) of Sb2WO6 in 60 min under simulated sunlight, which was much higher than that of pure g-C3N4 and Sb2WO6. This highly enhanced photocatalytic activity of the Sb2WO6/g-C3N4 composites can be mainly attributed to strong interfacial interaction promoting the photo-generated electron-hole separation and migration. The results of radical scavenger experiments showed that center dot O-2(-) and h(+) were the dominant reactive species in the photocatalytic reaction. Besides, the Sb2WO6/g-C3N4 composites showed excellent stability over several reaction cycles. Finally, a possible Z-scheme photocatalytic mechanism was proposed based on the experimental results.