S-Doped Ni_0.5Co_0.5Fe₂O₄ Porous Single-Crystalline Nanosheets for Electrocatalytic Oxygen Evolution

Abstract

Developing a highly efficient catalyst for the oxygen evolution reaction (OER) is of great significance for its application in electrocatalytic water splitting. Herein, a solid−solid transformation strategy has been developed to construct sulfurdoped Ni 0.5 Co 0.5 Fe 2 O 4 spinel porous single-crystal nanosheet arrays on nickel foam (S-NCFO/NF). The single-crystalline nanosheet self-assembled nanostructures can provide fast charge transfer channels. With the effect of S-doping, a distorted/incomplete octahedral structure nanosheet can be formed. The unique porous S-NCFO nanosheets can provide a large number of active sites and sufficiently contact the electrolyte to adsorb OH − and desorb O 2 . By virtue of the porous single-crystal nanosheet, sulfur-doped spinel structure, and the unique self-assembled nanosheet configurations, the S-NCFO/NF electrode exhibits enhanced OER performance with low overpotentials at 100 mA cm −2 of 300 mV in 1 M KOH and 317 mV in 1 M KOH + 0.5 M NaCl. The synthesis strategy provides insight for the preparation and application of self-assembled nanostructures in electrocatalytic seawater splitting.

Influence of Er2O3 Nanoclusters on Transition Metal Oxide Nanostructures in Water Oxidation

“…Among non-noble metal electrocatalysts, transition metal oxides (TMOs) like NiO, Co 3 O 4 , and Fe 2 O 3 have garnered attention for their notable attributes, including high stability in alkaline environments, abundance in the Earth’s crust, cost-effectiveness, nontoxicity, and high redox potential. − Various strategies for improving the electrocatalyst activities of TMOs include nanostructure synthesis, doping, support modification, defect engineering, and hybridization with other materials. , However, studies to enhance the stability and activity of the TMO electrocatalyst are still ongoing …”