Recent advances in nitrogen-doped graphene oxide nanomaterials: Synthesis and applications in energy storage, sensor electrochemical applications and water treatment

This review covers recent advances on production techniques, unique properties and novel applications of nitrogen-doped graphene oxide (NGO). The focal point is placed on the evaluation of diverse methods of production for NGO and reduced nitrogen-doped graphene oxide (NrGO) nanosheets using GO and graphite as carbon precursors. Variation in chemical composition of GO with variable N content, C-N bonding configurations and chemical reactive functionalities of NGO allow tuneable properties that render NGO a suitable material for various applications such as lithium-ion batteries, biosensors, supercapacitors and adsorption processes. NGO and NrGO exhibit significantly different performances compared to GO even with small amounts of N-doping. The type of C-N bonding and surface chemistries on the NGO are responsible for their unique electrical, mechanical, adsorption, chemical reactivity, photocatalytic activity, and optical properties. Various investigative techniques used to study NGO nanomaterials are also reviewed. Finally, future perspectives of NGO in this rapidly developing area are discussed.