N-graphene oxide and N-reduced graphene oxide from jujube seeds: Chemistry and mechanism

Abstract

The presence of heteroatom can enhance the charge density of graphene as well as improve its electrocatalytic properties to promote non-enzymatic sensing in contrast to pristine graphene. Earlier, nitrogen doped graphene was synthesized by most common precursor graphite using both oxidizing and doping agent. However, the use of carbon and nitrogen rich fruit wastes into the conversion of N-graphene oxide, without use of any doping agent and inert atmosphere has not been reported so far. In this work, a two-step approach underwent to synthesize nitrogen containing graphene (N-graphene) from non-graphitic carbon and nitrogen containing precursor at normal atmospheric condition. The synthesis of N-graphene from jujube seeds was carried out by pyrolysis at 250°C using different time intervals, which resulted in the formation of N-graphene oxide (N-GO) without any additional oxidizing agent and inert atmosphere. The cyclic six membered ring structures of glucose monomers present in fruit waste was found to be responsible for facilitating the development of polyhexagonal rings and aromatization during heat treatment, whereas the amino acids of fruit waste enhanced the nitrogen content to develop the N-GO. Further, the obtained N-GO was converted to N-reduced graphene oxide (N-rGO) in the presence of thiourea as a reducing agent.