Graphene Oxide/Iron Oxide Nanocomposites for Water Remediation

TLDR

Graphene oxide/iron oxide nanocomposites were produced via a fast one‑pot synthesis using K₂FeO₄ as a green oxidant, yielding low‑oxidation‑degree GO flakes decorated with iron oxide without toxic permanganates. The nanocomposite was characterized by SEM, TEM, XRF, XPS, FTIR, UV–visible, fluorescence, Raman spectroscopy, and HPLC, and its paramagnetic nature allows easy magnetic recovery from water. The ferrate/GO‑iron oxide system efficiently decontaminated real water samples containing dyes, pesticides, and pharmaceuticals, achieving 99 % removal in minutes and ranking among the best reported performances.

Abstract

Graphene oxide/iron (III–VI) oxides nanocomposites have been produced with a fast and one-pot synthesis. K2FeO4 (Fe(VI)-based compound), obtained from a dry synthesis, has been used as a green oxidant of graphite to produce graphene oxide, avoiding the use of the toxic permanganates. Graphene oxide flakes with a low oxidation degree and decorated with iron oxide have been obtained in one-step reaction. The material has been characterized by several techniques to investigate the structure (SEM, TEM analysis), the composition (X-ray fluorescence, XPS, FTIR, UV–visible, fluorescence, and Raman spectroscopy) and the performance (HPLC). The combined use of ferrate and graphene oxide/iron oxide is an efficient, cheap, and green alternative for water remediation. Real water samples containing different types of emerging pollutants (organic dyes, pesticides, and pharmaceutical drugs) have been efficiently decontaminated obtaining an abatement of 99% in a few minutes. The nanocomposite is paramagnetic and can be easily removed from water with a magnet after depollution. The materials have shown one of the best decontamination performance reported in the scientific literature so far.