Green reduction of graphene oxide using a mixture of chocolate and coffee powder

Graphene materials feature unique structure and optoelectronic properties. They have been utilized in various applications such as solar cells, batteries, sensors, and transistors. This material can be synthesized with a top-down approach which begins with the oxidation of graphite to obtain graphene oxide (GO) and is followed by the chemical reduction to produce reduced graphene oxide (rGO). However, the toxicity of common chemical reducing agent hydrazine is found to bring serious problem. Therefore, an alternative environmentally-friendly GO reduction remains a challenge. In this study, the reduction process was performed using natural reducing agents extracted from a combination of chocolate and coffee. The reduction has been successfully investigated using weight variation of chocolate and coffee; 2 wt%, 6 wt%, 10 wt%. It was found that the optimum result was displayed by using 6 wt% of chocolate and coffee powder. The result shows that chocolate and coffee have great potential as the green reducing agent.