Electrochemical behavior of glycine-mediated N-doped reduced graphene oxide

Abstract

In the present manuscript, N-doped reduced graphene oxide (rGO) has been synthesized by using an environmentally benign amino acid, glycine, as a reducing agent (N-rGOGly) under mild experimental conditions in aqueous medium and has been explored for its electrochemical behavior. It exhibited a fairly high value of specific capacitance (263 F g⁻¹ at 1 A g⁻¹), a high energy density/power density, a high coulombic efficiency, and long cycling stability. Annealing of this sample at a mild temperature of 300 °C produced crystalline N-doped rGO (N-rGOGly300) with a six-fold symmetry having a ‘‘d” spacing of 0.367 nm as was revealed by its HRTEM analysis. XPS, Raman, and ¹³C NMR analyses exhibited its enhanced graphitic character which was further evidenced by its more than six times increase in conductivity (69.78 S cm⁻¹) as compared to the non-annealed sample (11.4 S cm⁻¹) suggesting its possible applications for the fabrication of electrical devices. Annealing though resulted in the reduction of its pseudocapacitive contribution but it exhibited appreciably higher values of C_s of 191 F g⁻¹ at 1 A g⁻¹ and other electrochemical features.