Study of organic pollutant removal capacity and work function of magnetite/graphene oxide nanocomposites

In the present work, we focus on the correlation between the surface potential of magnetite/graphene oxide nanocomposites (Fe3O4/GO NCs) with the organic pollutant (Rhodamine 6 G dye, (R6G)) removal capacity of the nanocomposites. The effect of GO on both work function and R6G dye removal capacity of magnetite nanoparticles (Fe3O4 NPs) has been studied. The role of charge transfer in Fe3O4/GO NCs towards R6G dye has been investigated using scanning Kelvin probe microscopy (SKPM) set up, and it was found that the work function value of Fe3O4/GO NCs increases with increasing the amount of GO in the Fe3O4/GO NCs. This in turn results in shifting of Fermi level towards valance band in Fe3O4 NPs. We used UV-visible spectroscopy to measure the removal capacity of R6G dye through Fe3O4/GO NCs using aqueous medium. In Fe3O4/GO NCs, the GO sheets provide large surface area due to different functional groups like epoxide (C?O?C), carboxylic acid (?COOH), hydroxyl (?OH) to adsorb dye molecules and increase the work function with reduced removal capacity. Thus, our study clearly demonstrates that Fe3O4/GO NCs can be used for water clean-up process and optoelectronic devices.