Mechanistic insight into efficient removal of tetracycline from water by Fe/graphene

The release of pharmaceuticals into aquatic environments is a serious concern due to the persistence and potential health and environmental risks of these substances. Surface and ground waters are polluted with a variety of pharmaceuticals due to insufficient water purification processes in wastewater treatment plants. Here, we report a simple procedure for the production of composite materials consisting of zero-valent iron embedded in few-layer graphene, Fe/graphene, through induction annealing at 900 degrees C. Zero-valent iron was observed as magnetic 1 mu m-sized crystals embedded in the graphene matrix appearing in the alpha- and gamma-forms. This Fe/graphene composite was applied as an adsorbent for the removal of tetracycline (a pharmaceutical) from water. The Fe/graphene showed high tetracycline removal efficiency (422 mg/g) under optimized conditions. Furthermore, the Fe/graphene possessed self-regenerating features prolonging its lifetime and total removal capacity up to 660 mg/g, thus making it a potential material for removing tetracycline from water.