Fabrication of hexagonal shaped CuCo_2S_4 nanodiscs/graphene composites as advanced electrodes for asymmetric supercapacitors and dye sensitized solar cells (DSSCs)

摘要

In this report, CuCo_2S_4/graphene (abbreviated as CCS-G) hybrid electrodes were fabricated via facile and one step hydrothermal route. The fabricated electrodes were characterized by XRD, Raman, TEM, BET and XPS to investigate the structural, morphological and elemental composition properties. N_2 adsorption-desorption studies showed that CCS-G indicates the maximum specific area of 112 m~2 g~(-1) related to CCS (77 m~2 g~(-1)). The CuCo_2S_4/graphene electrode deliver a high specific capacitance 1625 F g~(-1) at relative current density of 2 A g~(-1) and high cyclic retention of 97% after 5000 cycles experiment. Interestingly, asymmetric device CCS-G//AC was fabricated and it shows high energy density of 27 Wh Kg~(-1) with relative power density of 5100 W Kg~(-1). The sandwich type dye sensitized solar cell (DSSC) was fabricated and tested the J-V and IPCE analysis. The finding reveals that CuCo_2S_4/graphene electrode shows high PCE (11.85%) and long term stability. The superior PCE of the composite is due to the heterostructure, mesoporous nature and high surface area with enhanced light harvesting capacity. Due to the high photovoltaic and electro-catalytic activity of CuCo_2S_4/graphene heterostructure can be useful for energy conversion and storage device applications.