Controlled Synthesis of 2D Nanostructured Bimetallic Oxide (NiMoO4) on Self‐Supported Nickel Foam for Boosted Electrocatalytic Seawater Oxidation Performance

The design and development of effective electrocatalysts containing nonprecious materials for oxygen evolution reaction (OER) in seawater splitting remains a significant challenge for large‐scale industrial hydrogen production. Nonprecious bimetallic oxide‐constructed catalysts are utmost promising candidates to obtain boosting electrochemical water oxidation performance. Herein, a transition bimetallic oxide nanostructure electrocatalyst as NiMoO 4 vertically standing nanosheet over the nickel foam substrate (NiMoO 4 /NF) for electrochemical water oxidation process in alkaline fresh/simulated seawater conditions is presented. NiMoO 4 nanostructure on NF substrate is successfully obtained using a straightforward hydrothermal reaction route and thermal annealing processes. The surface morphology with elemental characteristics of the resultant NiMoO 4 /NF sample exposes highly homogenous vertical standing nanosheets assembled on the NF surface. The electrochemical water oxidation performance of the as‐prepared electrodes demonstrates the function of diverse hydrothermal reaction times (3, 6, and 9 h) in fresh and simulated seawater electrolyte conditions. In alkaline seawater electrolyte conditions, optimal hydrothermal reaction time‐assisted NiMoO 4 /NF‐6 h electrocatalyst possesses significant OER electrocatalytic actives compared to the other samples. Similarly, NiMoO 4 /NF‐6 h catalyst exhibits a small overpotential of 429 mV to achieve a current density of 50 mA cm −2 with a Tafel slope value of 122 mV dec −1 for OER process. As a result, the resultant superior electrocatalytic performance of the optimal hydrothermal reaction time‐aided electrocatalyst (NiMoO 4 /NF‐6 h) is ascribed to highly accessible catalytic active centers and enhanced charge transfer kinetics at the interface for electrochemical reactions. Thus, proposed nanostructure‐constructed electrocatalysts could prove to be prospective OER candidates for electrochemical water oxidation.