Reduction mechanism of graphene oxide including various parameters affecting the C/O ratio

The most widely used process for the mass production of graphene involves the oxidation of graphite to graphene oxide (GO), followed by chemical reduction to produce reduced graphene oxide (rGO) or graphene. To date, several processes have been adopted to reduce GO with varying carbon-to-oxygen (C/O) atomic ratios. A controlled reduction methodology for the chemical reduction of GO has been the matter of choice for the researchers to obtain the desired functionalized graphene materials. For that, the structure of GO, chemical reactivity/efficiency of the reducing source, parameters affecting the extent of reduction, and the mechanism of action must be taken into consideration. This review directs a particular emphasis on all of such parameters systematically, which could possibly motivate researchers worldwide to frame new methodologies for the large-scale production of graphene-based materials.