Graphene oxide selenium nanorod composite as a stable electrode material for energy storage devices

Abstract

Selenium (Se), a member of the sulfur family, is considered as a potential alternative cathode material due to its high electronic conductivity and comparable volumetric capacity density to sulfur. Herein, we report on a simple one-step procedure to prepare trigonal selenium nanorods (t-Se) on graphene oxide (GO) without using any surfactant. The developed method does not utilize any harmful chemicals or harsh experimental conditions, and is, therefore, friendly from the environmental and economic point of views. We discovered that well-dispersed Se nanorods can be prepared at 20 mM Se under heating at 85 °C for 3 h. The successful growth of t-Se rods on GO sheets was confirmed by X-ray diffraction (crystalline structure), transmission electron microscopy (morphology), Raman spectroscopy (crystalline form and defects), and XPS technique (elemental composition). The Se nanorod-loaded GO composite (GO–Se) displayed a promising specific capacity of 405.5 mAh g−1 at a high current density (10 A g−1) and high cycling stability with a negligible capacity decay over 1000 cycles. Importantly, the GO–Se electrode delivered a high reversible capacity of 471.5 mAh g−1 at 0.5 A g−1. The improved electrical performance of the GO–Se composite could be attributed to the electrical conductivity and unique architecture of reduced graphene, which effectively enhances the utilization of active Se rods and significantly augment the electronic conductivity of the GO–Se electrode. The present study demonstrates that a hybrid system of 1D t-Se impregnated GO composite could be a promising cathode material for long-life batteries and other storage devices.