Optimized Co²⁺_(Td)–O–Fe³⁺_(Oh)electronic states in a spinel electrocatalyst for highly efficient oxygen evolution reaction performance

Abstract

The introduction of iron into Co3O4 can induce a change in the electronic states of Co3+, which is an effective means to regulate the oxygen evolution reaction activity.

Synthesis of Lattice‐Contracted Cobalt Disulfide as an Outstanding Oxygen Reduction Reaction Catalyst via Self‐assembly Arrangement

“…Hence, as illustrated by the schematic diagram of the electronic configuration of Co 3d orbital (bottom part of Figure 5d), the spin state of Co 2 + transformed from low spin to high spin brought about increased occupancy numbers of e g orbital, [28] which was consistent with the result of Co-K edge XANES and contributed to the formation of anti-bonding with oxygen molecular orbital in ORR process.…”

Constructed Interfacial Oxygen‐Bridge Chemical Bonding in Core‐Shell Transition Metal Phosphides/Carbon Hybrid Boosting Oxygen Evolution Reaction

“…[58,59] It is worth noting that the magnetic moment of CoÀ OÀ C@CoP (7.89) was much higher than that of CoP/C (4.33), indicating the higher spin density of CoÀ OÀ C@CoP, which is beneficial for OER. [60] We hope that our current results will provide a research basis for the future material design.…”

Regulating the Coordination of Co sites in Co3O4/MnO2 Compounding for Facilitated Oxygen Reduction Reaction

“…The Co K-edge XANES spectra of prepared catalysts showed an increased absorption intensity that was positively correlated with the number of Co-tetrahedra in the Co 3 O 4 bulk (Figure 4b, inset I). [41] Hence the cobalt sites of Cotetrahedra gradually increased during the growth process of Co 3 O 4 NPs. This suspicion was supported by the negative shifts of peak position in the first derivative of XANES (Figure 4b, inset II) that was often used to evaluate the oxidation state.…”

“…As shown in Figure 4c, the three typical peaks corresponded to the nearest scattering paths of the CoÀ O shell, the scattering paths from octahedrally coordinated cobalt to its adjacent cobalt sites, and the scattering path between two adjacent tetrahedrally coordinated cobalt sites, respectively. [16,41] These were annotated in the crystal diagram presented in Figure 4d. Moreover, a scattering path observed at R = 1.2578 Å was shorter than CoÀ O paths, especially present in ZÀ Co/Mn but almost disappeared in IÀ Co/Mn catalyst.…”