## 2 Materials and Methods  
### Preparation and Characterization of Graphenic Materials  
Graphene materials were prepared by the treatment of graphite oxide (GO) at high temperature. Natural graphite powders of various grain sizes--10 mesh, 100 mesh, and 325 mesh (supplied by Alfa Aesar, Thermo Fisher Scientific, UK, purity 99.8%) were used for the synthesis of GO through a modified Brodie's method ([PERSON], 1971). This procedure consists of the addition of 10 g of graphite (G) over 200 mL of tuning HNO\({}_{3}\), keeping the mixture at 0 \({}^{\circ}\)C. First, 80 g of KClO\({}_{3}\) was gradually added over 2 h. Afterward, the mixture was stirred for 21 h, maintaining the 0 \({}^{\circ}\)C temperature. The GO obtained was filtered and washed systematically with water until neutral pH and dried under vacuum at room temperature. The resultant samples were labeled GO\({}_{\text{m}}\), where m indicates the mesh size used.  
The GO\({}_{\text{m}}\) were exfoliated in a vertical quartz reactor under two different atmospheres. The first atmosphere consists of nitrogen (87 mL/min) producing rGO, while the second was a mixture of NH\({}_{3}\), H\({}_{2}\), and N\({}_{2}\) (10, 3, and 87 mL/min, respectively) generating NrGO.  
In order to study the effect of temperature and heating rate on the properties of rGO and NrGO, for each atmosphere described, five different exfoliation ramps were applied over GO\({}_{325}\). In a first ramp, 0.3 g of GO was introduced in the furnace and heated at 5 \({}^{\circ}\)C min\({}^{-1}\) to 250 \({}^{\circ}\)C; then, the sample was kept at this temperature for 30 min. The temperature was increased from 250 to 500 \({}^{\circ}\)C with a heating rate of 5 \({}^{\circ}\)C min\({}^{-1}\) and then kept at this temperature for 30 minutes. In a second and third ramp, GO was heated at 5 \({}^{\circ}\)C min\({}^{-1}\) and 10 \({}^{\circ}\)C/min respectively to 250 \({}^{\circ}\)C; then, the sample was kept at this temperature for 30 min. The temperature was increased from 250 to 700 \({}^{\circ}\)C using the same heating rates, and then this temperature was maintained for 30 min. In a fourth ramp, GO was heated at 5 \({}^{\circ}\)C min\({}^{-1}\) to 100 \({}^{\circ}\)C; then, the sample was kept at this temperature for 1 h. The temperature was increased from 100 to 700 \({}^{\circ}\)C with a heating rate of 10 \({}^{\circ}\)C min\({}^{-1}\); then, the sample was kept at this temperature for 5 min. Finally, in the fifth ramp, the GO was heated up to 250 \({}^{\circ}\)C at 20 \({}^{\circ}\)C min\({}^{-1}\); then, the sample was kept at this temperature for 30 min. The temperature was subsequently increased from 250 to 500 \({}^{\circ}\)C with a heating rate of 20 \({}^{\circ}\)C min\({}^{-1}\); then, the sample was kept at this temperature for 30 min.  
For the exfoliation of the samples GO\({}_{10}\) and GO\({}_{100}\), the temperature and heating rate used were selected according to the ramp that gave the higher value of surface area among the exfoliated samples of GO\({}_{325}\). The samples obtained were labeled rGO\({}_{\text{m}}\)-r and NrGO\({}_{\text{m}}\)-r, respectively, where m indicates the mesh size used and r indicates the ramp used.  
The characterization of the as-prepared materials was carried out by different techniques: elemental analysis, nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The detailed equipment and methods used are described in the electronic supporting information (ESI) file.