An Investigation of the Interface between Transition Metal Oxides (MnO_x, FeO_x, CoO_x and NiO_x)/MoO₃ Composite Electrocatalysts for Oxygen Evolution Reactions

Abstract

This study presents the synthesis of a multicomponent metal oxide electrocatalyst that increases the activity of the oxygen evolution reaction (OER). We synthesized transition metal oxides (MnOx, FeOx, CoOx, and NiOx) with MoO3 heterostructures through a solid-state reaction approach at low cost. In comparison to the other compositions, CoOx garnered higher attention and demonstrated superior performance on account of its large surface area and varied crystal facets. The MnOx-MoO3, FeOx-MoO3, CoOx-MoO3, and NiOx-MoO3 compositions attained an overpotential of 390 mV, 350 mV, 310 mV, and 340 mV, respectively, at a current density of 10 mA cm−2 in alkaline solution. The performance of OER was enhanced in CoOx-MoO3 at 10 mA cm−2, while FeOx-MoO3 exhibited a lower current density at 100 mA cm−2 than other metal oxides. The CoOx-MoO3 material exhibited a favorable crystal interface transition due to the presence of MoO3 oxide. For the first time, we report on the MoO3-to-(MnOx, FeOx, CoOx, and NiOx) interface crystal transition and the active surface area for OER catalytic activity in water-splitting processes. This investigation intends to develop an electrocatalyst that is capable of producing hydrogen with the use of heterostructure metal oxides.

Keywords

• water splitting
• electrocatalyst
• oxygen evolution reaction
• heterostructure
• metal oxide