Ultrafast air-plasma reduction-exfoliation of graphene oxide aerogel at room temperature for capacitive deionization

Graphene produced by reducing graphene oxide has been an emerging candidate for capacitive deionization (CDI) and energy storage. However, the key factor for its commercial applications depends on the production methods that essentially determine its cost-effectiveness. Herein, we report a facile air-plasma method to achieve the highly efficient reduction of graphene oxide aerogel within 1 s, at room temperature, and without the need of any chemicals. It is demonstrated that by adjusting the plasma power ranging from 20 to 150 W, the interlayer distance between graphene layers, reduction degree (oxygen content), specific surface area, specific capacitance, and salt adsorption capacity can be tuned effectively for the obtained 3D graphene aerogel (GA). We also verify the validity of the air-plasma method for fabricating composite of GA with long Ag (or MnO2) nanowires, which can well maintain their unscathed 1D structure and redox activity for capturing ions. This air-plasma strategy, owing to its simplicity, time-saving and cost-effectiveness, opens a new pathway to large-scale synthesis of high-quality graphene with promising applications in CDI and beyond. [Display omitted] •We propose an air-plasma method for reduction and exfoliation of GO aerogel.•The preparation process only takes within 1 s at room temperature.•The GA exhibits an adjustable interlayer spacing and specific surface area.•The desalination performance of GA exceeds that of most other carbon materials.