Green synthesis of graphene oxide by seconds timescale water electrolytic oxidation

Abstract

Graphene oxide is highly desired for printing electronics, catalysis, energy storage, separation membranes, biomedicine, and composites. However, the present synthesis methods depend on the reactions of graphite with mixed strong oxidants, which suffer from explosion risk, serious environmental pollution, and long-reaction time up to hundreds of hours. Here, we report a scalable, safe and green method to synthesize graphene oxide with a high yield based on water electrolytic oxidation of graphite. The graphite lattice is fully oxidized within a few seconds in our electrochemical oxidation reaction, and the graphene oxide obtained is similar to those achieved by the present methods. We also discuss the synthesis mechanism and demonstrate continuous and controlled synthesis of graphene oxide and its use for transparent conductive films, strong papers, and ultra-light elastic aerogels.

Emerging 2D Materials Produced via Electrochemistry

“…As a result, 90% of the exfoliated GO sheets were monolayers with an average size of 3.1 µm and a C/O ratio of 4.6. Almost at the same time, a modified two‐step strategy was explored by Pei et al to prepare GO sheets with a high level of oxygen content ( Figure a) . The first intercalation step was similar to the previous report, using 98 wt% H 2 SO 4 at a low voltage of 1.6 V, resulting in the blue stage‐1 GICs (Figure b,c).…”

“…The chemical oxidation of graphite powders and intercalation of inorganic ions have been achieved using a large amount of strong oxidants (e.g., KClO 3 and KMnO 4 ) in the presence of fuming HNO 3 and concentrated H 2 SO 4 . However, the complete oxidation process requires a long period (e.g., several hours or days), involving the release of hazardous byproducts (e.g., NO x and SO 2 ) and the risk of explosion due to the formation of highly reactive Mn 2 O 7 intermediates at elevated temperature . In addition, GO sheets produced in this way suffer from the pollution of residual metal ions and significant structural damage.…”

Flexible Planar‐Integrated Micro‐Supercapacitors from Electrochemically Exfoliated Graphene as Advanced Electrodes Prepared by Flash Foam–Assisted Stamp Technique on Paper

“…Electrochemical exfoliation of graphite foil was conducted in a two‐electrode system, in which a graphite foil and a platinum mesh were used as the anode and the cathode, respectively . Briefly, a graphite foil with thickness of 0.5 mm was cut into strips with size of 6 × 2 cm and dried in oven at 80 °C for 12 h before exfoliation.…”

“…Most importantly, this method reduces the damage to the graphene structure. The exfoliation efficiency is higher, making it easy to realize the batch preparation of high‐quality graphene …”

Study on morphology of LaFeO3 nanofibers under different voltage connections

“…Due to the rapid development of modern society, a large number of organic or inorganic pollutants have been produced, which have caused serious environmental problems . To solve the pollution problems, various techniques have been adopted, such as electrolytic oxidation, biotechnology, adsorption, and so on. However, these methods are not only costly but also inefficient.…”