Fabrication of the Fe3O4/laser-induced graphene as an adsorbent for the household-derived microplastics

Abstract

Taking away Microplastics (MPs), which pose a serious threat to humanity and ecosystem, is necessary. Even though substantial exertions have been used to sufficiently remove MPs, it is still a difficult problem. In this study, we proposed a novel Fe3O4/laser-induced graphene fabricated by simple laser irradiation on the surface of a prepared polymer by stirring mixing polydimethylsiloxane (PDMS), lignin powder, and iron oxide, to efficiently adsorb MPs derived from household. Subsequently, the Fe3O4-laser-induced graphene particles (Fe3O4-LIGPs) were fabricated via razor scrapping and heat treatments. The novel Fe3O4-LIGPs sufficiently removed three kinds of MPs (melamine – particle size: 2 and 10 μm, polystyrene – particle size: 10 μm, polyamide - particle size: 50 μm) within 5 hours and were easily separated from the solution due to the iron oxide's strong magnetism. The Freundlich isotherm model, the pseudo-first, and second-order kinetics were adopted to evaluate the Fe3O4-LIGPs. The maximum adsorption capacities of the Fe3O4-LIGPs for the different types of MPs were 1400 (polyamide, 50 μm), 1250 (polystyrene, 10 μm), 1050 (melamine – 10 μm), and 775 (melamine – 2 μm) mg∙g-1. For the evaluation of reusability, the Fe3O4-LIGPs were recycled seven times for each MP after heat treatments.