Simultaneous Self-propagating Reduction and Cobalt Oxide Incorporation in Graphene Oxide Films for Supercapacitor Applications

In this study, we developed a self-propagating process where a graphene oxide (GO) film is chemically reduced and simultaneously incorporated with pseudo-capacitive cobalt oxide nanoparticles. For this process, a GO film was prepared by combining GO dispersion and cobalt oxide precursor. Once an end of the GO film was ignited in a controlled ambient condition, a reduction front rapidly swept along the film. The heat generated from the GO reduction not only advanced further reduction but also fueled the chemical reaction, to turn the precursor material into the cobalt oxide within the reduced GO (rGO). The morphologies, chemical compositions, and capacitive performances of the rGO were characterized to investigate the differences caused by various precursor content ratios. Then, the process was optimized to find the most stable and highest performing combination of incorporation precursor amounts and base temperatures. This study advances the efficient exploitation of the self-sustaining reduction of GO to quickly produce cobalt oxide incorporated rGO films, for supercapacitor applications on a large scale.