Designing Multifunctional Co and Fe Co-Doped MoS2 Nanocube Electrodes for Dye-Sensitized Solar Cells, Perovskite Solar Cells, and a Supercapacitor

In the present study, three types of specific solid, core–shell, and hollow structured cobalt and iron co-doped MoS2 nanocubes (denoted as s-Co-Fe-MoSx, c-Co-Fe-MoSx, and h-Co-Fe-MoSx) are controllably synthesized for the first time by regulating the reactant mass ratios. The prepared Co-Fe-MoSx nanocubes can function as a counter electrode in dye-sensitized and perovskite solar cells (DSCs and PSCs) and a working electrode in a supercapacitor. In the DSC system, the c-Co-Fe-MoSx nanocubes exhibit the maximum catalytic activity to the Co3+/2+ redox couple regeneration, and the device achieves a power conversion efficiency (PCE) of 8.69%, significantly higher than the devices using s-Co-Fe-MoSx (6.61%) and h-Co-Fe-MoSx (7.63%) counter electrodes. Similarly, all of the prepared Co-Fe-MoSx nanocubes show decent activity in PSCs and the device using the c-Co-Fe-MoSx counter electrode achieves the highest PCE of 6.88%. It is worth noting that, as the supercapacitor working electrode, the h-Co-Fe-MoSx exhibits a specific capacitance of 85.4 F g–1, significantly higher than the parallel values achieved by the s-Co-Fe-MoSx and c-Co-Fe-MoSx electrodes under identical conditions.