Tailoring the structural properties of simultaneously reduced and functionalized graphene oxide via alkanolamine(s)/alkyl alkanolamine for energy storage applications

Abstract

Herein, we report a simple hydrothermal approach for the simultaneous reduction and functionalization of graphene oxide (GO) employing three different types of alkanolamine(s)/alkyl alkanolamine (monoethanolamine (MEA), triethanolamine (TEA) and N,N-diethylethanolamine (DEEA) without using any external reductant/surfactant. The simultaneous reduction and functionalization of GO was evidenced by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses. Interestingly, the simultaneous reduction and functionalization of MEA, TEA and DEEA molecules on GO resulted in stabilized reduced graphene oxide (rGO) structures with enhanced surface area for rGO-MEA (967 m2/g), rGO-TEA (881 m2/g) and rGO-DEEA (430 m2/g) compared to that of non-functionalized rGO (376 m2/g). Furthermore, the differences in the capacitive performances of functionalized rGO(s) have been investigated in terms of different surface chemistry, surface area, graphitic character and conductivity. Among all the as-synthesized functionalized rGO(s), rGO-TEA exhibited improved specific capacitance (827 F/g at 1 A/g), long cycling stability, high coulombic efficiency and high energy/power density, demonstrating their potential for supercapacitor applications.