Enhanced photocatalytic properties of TiO2/rGO nanocomposites Doped with CdS

[Display omitted] •TiO2/rGO nanocomposites (NC) with low concentration of CdS were synthesized.•The photocatalytic activity of NC 5-fold increased when 5 wt% CdS was used.•The photodegradation of MB is 14.4 and 11.6 times higher than for pure NC or CdS.•The reasons for the increase in photocatalytic activity of NC/CdS have been studied. To increase the photocatalytic activity of nanocomposite based on TiO2 and rGO (NC) and improve its photosensitivity in the visible region of the spectrum, the influence of CdS concentration (1 to 10 wt% with respect to NC) on its physicochemical and photocatalytic properties was studied. The addition of CdS to NC leads to a significant increase in the photocatalytic activity. An almost fivefold increase in photocurrent compared to pure NC was registered for NC/CdS_5%. Data on Methylene blue photodegradation showed that after 210 min of irradiation, only 5 % of dye molecules remained in solution. This value is 14.4 and 11.6 times higher than that of pure NC or CdS, respectively. Enhanced photocatalytic activity is related both to the improvement of NC absorption in the region of 400–800 nm and the decrease of the band gap width of NC upon addition of CdS, as well as the significant change in the electrophysical characteristics of the nanocomposite.