Photo catalytic reduction of Cr6+ by ZnO decorated on reduced graphene oxide (rGO) Nanocomposites

Abstract ZnO decorated rGO nanocomposites (ZnO∙x% rGO NC (x = 1, 5, 10, 15, 20 and 25)) were fabricated using hydrothermal method. Elemental mapping of Zn ions on the surface of ZnO∙rGO were distributed over the surface. SEM images showed that ZnO nanoparticles have agglomerated into micron size clusters. EDS measurements were used to determine the exact chemical content of NC’s. FTIR spectra indicated that GO had been reduced to rGO by hydrothermal fabrication process used. The shifts of G band in Raman spectra indicate the presence of interfacial Zn O C bonds. UV–vis absorption studies were used to monitor the amount of Cr6+ ions in solutions after their exposure to light. Photocatalytic reduction of toxic Cr6+ was observed by time change in the absorption of light at two wave lengths, 273 nm and 373 nm. The enhancement of photo reduction rate increased, reaching a maximum at x = 10 % and then decreased.