| dc.description.abstract | In this study, we investigate the mechanism and applications of the restoration on reduced graphene oxide(rGO). Here, graphene oxide(GO) paper is prepared by a Hummers’ method and doctor blade coating, followed by chemical reduction by using Hydroiodic acid(HI) for preliminary reduction. Finally, the photoreduction was carried out to further restore graphene by using light-focusing Xenon flash lamp. The optimized condition of photo reduction was obtained by controlling temperature and flash shot. The optimized parameters to restore graphene are subjected to 3 flash shots at 25 ℃, followed byand ramping to the 50 ℃ for additional 3 shots. The resultant rGO shows high C/O ratio(36.2) and high crystalline(Raman D/G ratio=0.24; 2D/G ratio=0.43). Due to the high efficient deoxygenation by photoreduction, the as-prepared rGO paper exhibits porous structure, where the pore size was about 300 nm in average. The study suggest that the comprising of HI chemical treatment and Xenon flash facilitate the photolysis reaction of iodic molecular, leading to high efficient break of epoxy bond (higher C/O ratio). Meanwhile, the exothermic heat during GO reduction process a chain reaction, where heat was found to propagate over whole material, thus further restore graphene defects.
To evaluate the performance and particle application, the as-prepared rGO paper with various reduction conditions were employed as electrodes in a symmetric type supercapacitors by selecting 6 M KOH as electrolyte. The rGO treated by comprising of HI and Xenon flash (rGO-HI-Xe) shows higher specific capacitance of 28 F/g, which was 233% increased when compare to that (12 F/g) of rGO treated by HI(rGO-HI). This was attributed to high specific surface area and diffusion path created from porosity and fluffy structured rGO-HI-Xe samples, thus promoting ion transport capability. In addition, the rGO paper can be utilized as thermal pad. The rGO-HI samples show a thermal diffusivity and thermal conductivity of 439.18 mm2/s and 1056 W/m．K, respectively. The requirements for high performance thermal pad including high density of stacking structure, low porosity and defect density. This work provides a facile and high efficiency method for graphene restoration, which was potential for high quality graphene production and its related applications. | en_US |