Facile tool for green synthesis of graphene sheets and their smart free-standing UV protective film

Green, cost-effective and scalable method was developed for synthesis of graphene sheets from sugar beet leaves. Considerable graphene sheets were synthesized through drying, and carbonization of sugar beet leaves then, exfoliation from the obtained graphite flakes using ultrasonication in presence of polyvinyl alcohol (PVA). High quality less defected and large dimensions graphene sheets of 50% yield were obtained. The mass ratios of PVA and their effect on exfoliation were studied. Free-standing transparent graphene sheets thin film was developed of an average thickness of 136 mu m. The transparent free-standing graphene sheets thin film transparent to visible rays and blocked harmful UV rays by similar to 70% which is among the highest reported value for UV protective thin film. To the best of our knowledge this the first time of free-standing transparent graphene sheets film prepared from renewable source and used as UV filter. This work will open new avenues for using renewable and costeffective UV protective materials and filters.