Hydrothermal Synthesis of Zirconium based Binary Metal Oxides and their Electrochemical Study for Oxygen Evolution Reaction(OER).

Abstract

Electrochemical water splitting has become a point of major interest to researchers to produce an efficient, durable, and stable electrocatalyst. In this work, we report the Zirconium-based binary metal oxide composites (ZrO2/Co¬3O4 and ZrO2/Mn3O4) in different ratios. These composites show excellent electrochemical activity for Oxygen evolution Reaction (OER).The composites were prepared by simple hydrothermal method in the presence of urea. The composite (ZrO2/Co3O4 in ratio of 0.1:0.9 and the composite ZrO2/Mn3O4 in ratio of 0.3:0.7 showed the best catalytic activity for OER. The composite , ZrO2/Co3O4, (0.1:0.9) exhibited the lowest over-potential 302mV and 353mV at the current density of 15mAcm-1 and 50mAcm-1, lowest Tafel slope of 85mVdec-1at current density 20mAcm-2. The composite, ZrO2/Mn3O4 in ratio 0.3:0.7 performed best of all of its composites in different ratios and pure oxides showing over-potential 290 mV and 365 mV at current density of 15 mAcm-1 and 50 mAcm-1 at 5mVs-1 scan rate in alkaline electrolyte with Tafel slope 91 mVdec-1. Both the best-performing composites showed excellent stability at 10 mAcm-2 current density for 24h. The OER activity of both the composites can be attributed to the synergistic effect of two oxides making up the composite and optimization of active sites modulating the intrinsic catalytic activity of the metal oxides.