Study of the Graphene Oxide Reduction Reaction Kinetics: Modeling and Electrical Monitoring of the Process

Chemical reduction of graphene oxide is considered to be the most promising method for the large-scale, fast, and low-cost production of graphene in solution. Despite its importance, there is a lack of studies regarding this process, the detailed description of which would allow for optimization in terms of both time and cost. Moreover, a rapid and real-time method for monitoring the reaction could further optimize the procedure. The aim of this work is to study the kinetics of the chemical reduction of graphene oxide using ascorbic acid as a green reducing agent. For this purpose, the reduction reaction is monitored by measuring both the UV–vis spectra and the electrical conductance of the reaction solution, which increases as the reduction of graphene oxide proceeds. An accurate mathematical model of the reaction kinetics is proposed. Excellent agreement between the experimental and simulated curves was obtained using an uncoupled system of first-order differential equations for each reactant. The electrical monitoring of the reaction progress is validated by comparing the reduced graphene oxide concentrations obtained by the two methods, with no significant differences.