Renewable Reduced Graphene Oxide-Based Oil-Absorbent Aerosols: Preparation and Essential Oils Absorption Ability

This study proposes a rapid solid-phase extraction (SPE) of essential oils from citrus, including pomelo and lemon, using graphene aerosol (GA) as sorbent based on a pi-pi conjugative and hydrophobic interaction. The graphene aerosol was fabricated by the hydrothermal reduction low-temperature freeze-drying method, and its morphology and structures were analyzed by scanning electron microscopy (SEM) and X-ray photoclectron spectroscopy (XPS). The specific surface area and pore volume of the samples were measured using N-2 adsorption. The effects of amount of sorbent, extraction time, and extraction temperature on extraction were investigated. Maximal extraction yields of 2.70% and 2.47% were achieved under optimal conditions for pomelo and lemon, respectively. In addition, this extraction could be completed rapidly without adding another solvent and tedious processing steps such as centrifugation and evaporation of organic solvent. Besides, the sorbent also can be reused with heat treatment. This simple, rapid, environmentally friendly, and cost-effective method had been successfully applied to extract essential oils in two types of citrus. Meanwhile, it offers a potential application for extraction and analysis of essential oils from plants.