Multi -functional zinc cobaltite materials for perovskite solar cell and hydrogen evolution reaction applications

Spinel-structured zinc cobaltite nanoparticles (ZnCo₂O₄ NPs) were successfully synthesized <i>via</i> a hydrothermal method, and their functionality in perovskite solar cells (PSCs) and hydrogen evolution reactions (HERs) was explored. ZnCo₂O₄ NPs were incorporated with methyl ammonium lead iodide (MAPbI₃). ZnCo₂O₄-MAPbI₃ was used as an absorber layer in perovskite solar cells, and its photovoltaic behaviour was examined. The fabricated ZnCo₂O₄(Z2)-MAPbI₃-based PSC exhibited the highest PCE of 9.58%, with a fill factor (FF) of 0.59, an open circuit voltage (<i>V</i>_oc) of 0.9 V and a short circuit current (<i>J</i>_sc) of 18.05 mA cm^-2. The fabricated device showed stability by retaining 84% of its original efficiency under ambient conditions. Additionally, ZnCo₂O₄ NPs were used as electrocatalysts for hydrogen evolution reactions. The ZnCo₂O₄ catalyst exhibited excellent electrocatalytic activity and achieved an overpotential of 109.21 mV at 10 mA cm^-2.