A facile preparation of edge etching, porous and highly reactive graphene nanosheets via ozone treatment at a moderate temperature

•A facile method to modify graphene nanosheets by ozone treatment.•The edge etching, porous and highly reactive graphene nanosheets were prepared.•The ozone treatment time and temperature jointly affect the final results.•The dispersion of modified graphene nanosheets was significantly improved.•The modified graphene nanosheets can be conveniently used for further application.

A simple method to modify thermal-exfoliated graphene nanosheets (T-GNS) by using streaming ozone under different time and temperature is described in this paper. The results indicated that a wide variety of oxygen-containing groups such as COH, COC, CO and COOH could be introduced on the surface of T-GNS by ozone treatment. Especially when ozone modification was taken under 80 °C for 20 min, the atomic ratio of O/C was increased to 0.503, and the percentage of carboxyl groups was up to 14.37%, which was more than 10 times compared with the original T-GNS. In addition, it is worth mentioning that ozone treatment under a moderate temperature could cause etching on the edge of T-GNS and form porous structure in basal plane. As a result, the dispersion of ozone-treated T-GNS in aqueous solution was greatly improved, and the enhanced oxygen-containing groups and dispersion would facilitate its further functionalization and application.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide