Interfacial coupling effects on adsorptive and photocatalytic performances for photoresponsive graphene-wrapped SrTiO@Ag under UV-visible light: experimental and DFT approach.

Understanding the graphene/semiconductor/metal interactions is crucial to design innovative photocatalytic materials with efficient photocatalytic activity for environmental cleanup applications. SrTiO on reduced graphene oxide (rGO) with various graphene contents was successfully synthesized in this study utilizing a simple hydrothermal method, followed by decorating the surface with Ag particles by using the photodeposition process. Under UV-visible light irradiation, the resulting composites were tested for their improved photocatalytic activity to decompose methylene blue (MB). The prepared photocatalysts were characterized by XRD, SEM, EDX, DLS, FT-IR, Raman spectroscopy, and DRS. First-principle density functional theory calculations (DFT) were also carried out by using the generalized gradient approximation (GGA) and PBE functional with the addition of on-site Coulomb correction (GGA + U). The obtained SrTiO/rGO@Ag composites showed great improvement in the photocatalytic performances over pristine SrTiO. For the degradation reaction of MB, SrTiO/rGO@Ag composites yielded the best photocatalytic activity with efficacy reach 94%, which was also shown that it could be recycled up to four times with nearly unchanged photocatalytic activity.