Co₃O₄/Fe_0.33Co_0.66P Interface Nanowire for Enhancing Water Oxidation Catalysis at High Current Density

Abstract

Designing well‐defined nanointerfaces is of prime importance to enhance the activity of nanoelectrocatalysts for different catalytic reactions. However, studies on non‐noble‐metal‐interface electrocatalysts with extremely high activity and superior stability at high current density still remains a great challenge. Herein, a class of Co3O4/Fe0.33Co0.66P interface nanowires is rationally designed for boosting oxygen evolution reaction (OER) catalysis at high current density by partial chemical etching of Co(CO3)0.5(OH)·0.11H2O (Co‐CHH) nanowires with Fe(CN)63−, followed by low‐temperature phosphorization treatment. The resulting Co3O4/Fe0.33Co0.66P interface nanowires exhibit very high OER catalytic performance with an overpotential of only 215 mV at a current density of 50 mA cm−2 and a Tafel slope of 59.8 mV dec−1 in 1.0 m KOH. In particular, Co3O4/Fe0.33Co0.66P exhibits an obvious advantage in enhancing oxygen evolution at high current density by showing an overpotential of merely 291 mV at 800 mA cm−2, much lower than that of RuO2 (446 mV). Co3O4/Fe0.33Co0.66P is remarkably stable for the OER with negligible current loss under overpotentials of 200 and 240 mV for 150 h. Theoretical calculations reveal that Co3O4/Fe0.33Co0.66P is more favorable for the OER since the electrochemical catalytic oxygen evolution barrier is optimally lowered by the active Co‐ and O‐sites from the Co3O4/Fe0.33Co0.66P interface.

Promoting Oxygen Evolution Reaction of Co‐Based Catalysts (Co3O4, CoS, CoP, and CoN) through Photothermal Effect

“…Moreover, to further evaluate the accessibility of active sites, the electrochemical active surface areas (ECSAs) of different electrodes were estimated by extracting the electrochemical double‐layer capacitance ( C dl ) from the CV technique (Figure S3, Supporting Information) . As shown in Figure a, the calculated C dl value for Co 3 O 4 ‐5 (121.2 mF cm −2 ) is significantly higher than that of bare Co 3 O 4 electrode without NIR irradiation (77.3 mF cm −2 ).…”

Multifunctional Transition Metal‐Based Phosphides in Energy‐Related Electrocatalysis

“…Successively, similar interfacial synergistic effects were also observed on Ni 5 P 4 @NiCo 2 O 4 , Co 2 P–Ni 2 P/TiO 2 , and sc‐Ni 2 P δ− /NiHO, in which metal oxide/hydr(oxy)oxide was incorporated to manipulate the water dissociation kinetics. We note here that so far most of the interfacial engineered TMPs are designed for HER while rarely reported in OER or ORR, probably due to their more complex reaction mechanisms.…”

Surface Reorganization on Electrochemically‐Induced Zn–Ni–Co Spinel Oxides for Enhanced Oxygen Electrocatalysis

“…[1] Spinel-type (A X B Y O Z ) complex oxides with multiple cations can show av ariety of chemical ordering between cations at the Ao rBsites,t hus exhibiting various electrocatalytic properties. [2] In particular, NiCo 2 O 4 has shown remarkable promise as an electrode for energy equipment, owing to its earth abundance,e xcellent stability,a nd rich redox reactions. [3] However,t he performance of NiCo 2 O 4 without further tuning is still falling short of the level required for the actual demand, thereby inspiring us to find more effective strategies for structure optimization.…”