In situ measurement of the specific surface area of reduced graphene oxide using time-resolved laser induced incandescence

Reduced graphene oxide (rGO) produced by the rapid thermal expansion of graphite oxide is a promising alternative to graphene for applications requiring large volumes and some chemical functionality on the graphene, since this approach offers potentially high yields and throughput. However, the surface area and single layer dispersibility of the resulting rGO powder depends heavily on precursor moisture content, chemistry and morphology, as well as and process parameters that include residence time and quenching rates. While large-scale commercial deployments have been demonstrated, there are currently no real-time diagnostics capable of assessing inline material quality. In this study, we propose time-resolved laser-induced incandescence (TiRe-LII) as a means to derive the real-time relative specific surface area (S_sp) of rGO particles which is expected to be a strong indicator of single sheet dispersibility. The TiRe-LII derived S_sp were found to be consistent in both magnitude and trend to those found through batch gas adsorption measurements analyzed by fitting the Brunauer-Emmett-Teller (BET) isotherm.