Morphological control of RGO/CdS hydrogels for energy storage

Abstract

As a newly developed material system, graphene-based three-dimensional (3D) architectures have been receiving considerable attention due to their multifunctional properties. Herein, we explore the synergistic effect of combined CdS and graphene hybrids in 3D architectures and investigate their application in electrochemical energy storage. A facile hydrothermal procedure is used to prepare 3D reduced graphene oxide/CdS (RGO/CdS) hydrogels, and three different morphologies of CdS (ball-like, rod-like, needle-like) in the hydrogels are obtained by controlling the synthesis conditions. The results showed that the morphology of CdS significantly affects the electrochemical properties of RGO/CdS. The electrode prepared with needle-like CdS nanoparticles exhibited the highest specific capacitor value of 300 F g⁻¹ at a scan rate of 5 mV s⁻¹, which shows outstanding cycling stability with 94% capacitance retention after 1000 cycles of charge/discharge. These findings demonstrate the possible application of 3D RGO/CdS architectures in energy storage.