Synthesis and photocatalytic activity of g-C3N4/CdS materials under visible light

The g-C3N4/CdS composite photocatalysts consisting of cadmium sulfide (CdS) and graphitic carbon nitride g-C3N4) with a different mass ratio of CdS were successfully prepared and denoted as CNCS-1:1, CNCS-1:3, CNCS-1:5. The obtained materials were characterized by X-Ray diffraction (XRD), infrared spectra (IR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The UV-vis DRS results showed that CNCS-1:1, CNCS-1:3 and CNCS-1:5 materials possess bandgap of around 2.31, 2.25 and 2.28 eV, respectively. The photocatalytic activity of the materials was assessed by degradation of methylene blue (MB) under visible light. Among the three materials, CNCS-1:3 exhibited the highest photocatalytic activity. The enhancement of photocatalytic activity of the CNCS-1:3 (or g-C3N4/CdS) composites compared to single components, g-C3N4 and CdS was observed, which can be attributed to the reduction of combination rate of photogenerated electron – hole pairs in the composites.