Additive-free natural oil templated synthesis of reduced graphene oxide 3D foams for absorbent applications

Abstract

This article describes a novel and simple method for fabricating reduced graphene oxide (rGO) 3D foams using a natural oil (canola)–graphene oxide (GO) suspension emulsion templated technique. This method utilizes ultrasonic waves to arrange GO sheets in a stable position in an oil–water emulsion, thus enabling the economical and environmentally friendly fabrication of rGO 3D foams with controllable spherical pore sizes ranging from 5 to 200 μm through a hydrothermal technique. The pore size can be controlled using an emulsion mixing technique and the size of the GO sheet, where using a larger GO sheet results in a larger pore size. Compared to a smaller GO sheet, a larger GO sheet can also result in a final rGO foam with a more stable emulsion and greater structural stability. The 3D foams made in this way exhibit interconnected micro-sized voids, thus resulting in better permeability, which mades the fabricated material highly suitable for waste liquid absorption. The synthesized materials exhibited maximum volume capacities of 96.1% for organic solvent (IPA) and 88.1% for oils (olive). Moreover, its organic solvent absorption exhibited no performance drop, even after 10 cycles. Its absorption capacity for oil also remained at 79%, even after 5 cycles.

Keywords

• Self-assembly
• Liquid template
• Natural oil template
• rGO 3D foam
• Oil absorption