Visible-light driven photocatalytic degradation of organic dyes by carbonized palladium-impregnated graphene oxide quantum dots

In this study, palladium impregnated graphene oxide quantum dots (Pd-GOQD) have been synthesized by biogenic carbonization. The formation of Pd-GOQD and GOQD was confirmed by physicochemical techniques such as Brunauer–Emmett–Teller (BET), photoluminescence spectroscopy, XRD, Raman spectroscopy, XPS analysis, and HAADF-STEM analysis. TEM analysis revealed that GOQD and Pd-GOQD are spherical, with a mean size of around 2.9 and 3.7 nm, respectively. The photocatalytic activities of Pd-GOQD and GOQD using methylene blue (MB) and methyl orange (MO) dye under visible light were investigated using spectroscopic analysis. Pd-GOQD showed nearly better dye degradation efficiency as 90% dye was reduced within 75 min compared to 50% efficiency of GOQD. Kinetic of the reduction process of MB and MO was well correlated with first-order kinetics. Besides, the Pd-GOQD exhibited its regeneration and reusability as its photo-degradation performance remained unaffected after five successive reuses. Hence GO-Pd nanocomposite was a promising option for removing synthetic dyes from aqueous solutions.