One-step facile hydrothermal synthesis of heteroatom-doped porous graphene reduced comparatively by different reductants for high performance supercapacitors

Abstract

Taking advantage of hydrothermal methods to reduce graphene oxide (GO) is a convenient way and different heteroatoms on graphene or reduced graphene oxide (RGO) are vitally significant to its performance for application in supercapacitors. Accordingly, our work here is to implement a facile one-step hydrothermal reduction approach to obtain diversely doped graphene using various reductants of HI, Na2S2O3, NaBH4, N2H4·H2O, CS(NH2)2, by which I-doped, S-doped, B-doped, N-doped, and N, S dual-doped RGOs (represented as I-RGO, S-RGO, B-RGO, N-RGO, N/S-RGO, respectively) were fabricated. Through electrochemical characterization, it is presented that their electrochemical capacitance properties are ranked approximately in the order of N/S-RGO > N-RGO > S-RGO ≥ B-RGO > I-RGO, whereas I-RGO is in possession of a wider potential window than the others. Further structural and chemical analyses indicate that the O content within the RGOs is a primary effect on their performance, followed by the assistances from disparate heteroatom dopants existed in the RGOs and the porous construction inside graphene. As a result, a high specific capacitance of 263.3 F g-1 is obtained in N/S-RGO at the current density of 1 A g-1.