Photodegradation of methylene blue from waste water under visible light and bacterial growth inhibition by GO and rGO blended CdO: Mn nanoparticles– a comparative study

CdO: Mn (CM), graphene oxide (GO) blended CdO: Mn (GCM) and reduced graphene oxide (rGO) blended CdO: Mn (rCM) NPs were synthesized by chemical precipitation method. Comparison has been made on their photocatalytic and antibacterial properties. XRD study shows that all the samples are arranged in cubic form. With GO blending, the crystallite size of pure CdO decreased from 52 nm to 47 nm, and with rGO blending to 42 nm. Cd, Mn, and O in CM, GCM and rCM was ascertained from the EDS spectra. Optical band gaps were 2.44, 2.39 and 2.41 eV for the CM, GCM and rCM NPs. Photodegradation nature of CM against methylene blue dye under visible light irradiation increased with GO and rGO blending. The degradation efficiencies were 74, 86.2 and 94.7% for the CM, GCM and rCM catalysts after 90 min. The first order rate constants were 0.01507, 0.02109 and 0.02712 min− 1 for the CM, GCM and rCM catalysts. Remarkable antibacterial activity was realized for the rCM sample better than GCM and CM NPs against S. aureus and E. coli bacterial strains. These outcomes clearly indicates that the inclusion of GO and rGO into CdO: Mn matrix improves its photocatalytic and antibacterial properties.