CoS₂/RGO hybrid composites as catalysts for efficient counter electrodes in Pt-free dye-sensitized solar cell applications

Dye-sensitized solar cells (DSSCs) have gained recognition as a promising indoor photovoltaic technology, drawing considerable attention for their ability to convert light into electricity. In this study, we present a straightforward one-step hydrothermal synthesis method for producing cobalt sulfide nanoparticles decorated with reduced graphene oxide (CoS₂/RGO) nanocomposites, serving as an efficient counter electrode (CE) material for DSSCs. The CoS₂/RGO nanocomposites exhibited a chain-like structure formed by RGO nanosheet-decorated spherical particles interconnected with CoS₂. Demonstrating excellent electrocatalytic activity with a low Epp (peak-to-peak separation) value, the CoS₂/RGO nanocomposites outperformed pristine CoS₂ nanoparticles. Moreover, the power conversion efficiency of the CoS₂/RGO hybrid structure-based CE surpassed that of the pristine CoS₂ nanoparticles. These findings suggest that the facile synthesis of CoS₂/RGO nanocomposites holds great promise as an electrode material for effective CEs in DSSC applications.