Efficient transition metal Oxide/rGO composite as a Pt-free counter electrode for DSSCs

Dye-sensitized solar cells (DSSCs) represent a promising renewable energy technology due to their low-cost fabrication and design flexibility. This study introduces a novel quaternary hybrid transition metal oxide and carbon composite counter electrode (CE) consisting of CuO, Co₃O₄, CoMoO₄ and rGO. Each component contributes distinct electrical and morphological properties that enhances the composite’s performance. CuO exhibits a stick-like structure for unidirectional charge transport, Co₃O₄ has a spherical morphology for uniform dispersion and enhanced catalysis, CoMoO₄ forms rice-like particles for improved conductivity and stability, and rGO offers a sheet-like structure for high conductivity and surface area. The synergy of these morphologies enhances catalytic activity and conductivity, addressing the limitations of Pt-based CEs. When integrated with a TiO₂ photoanode and iodine-based electrolyte, The CuO/Co₃O₄/CoMoO₄/rGO composite demonstrated a power conversion efficiency of 7.53%, achieving 96.29 % of the Pt-CE, making it a cost-effective and sustainable substitute to Pt in DSSCs.