Phase‐Reconfiguration‐Induced NiS/NiFe₂O₄ Composite for Performance‐Enhanced Zinc−Air Batteries

Abstract

Metal−air batteries have attracted great attention because of their high energy density merits, among which zinc−air batteries (ZABs) are of great interest owing to their high energy density, intrinsic safety, and low cost. However, sluggish kinetics of the electrochemical oxygen evolution reactions and oxygen reduction reactions (OER and ORR) greatly hinder the development of ZABs. [5,6] Preparing a low-cost electrocatalyst with low overpotential and high stability is thereof a key issue. Effective synthesis methods are appealing to obtain robust catalysts. [7][8][9] Previous reports show that modifying the surface or bulk of materials by constructing composites, such as heterogeneous phase constructing, vacancy constructing, and interfacial engineering, can largely improve the performance of catalysts. [10][11][12][13] With regard to structural regulation, disrupting long-range order by constructing composite structures facilitates to obtain unexpected catalytic properties due to the synergistic coupling effect. [4,14] These methods can merely improve the performance of specific catalytic reactions, however, the method universality remains being improved.Surface modification and reconstruction are interesting topics from a viewpoint of catalysis, and many challenges Constructing composite structures is an essential approach for obtaining multiple functionalities in a single entity. Available synthesis methods of the composites need to be urgently exploited; especially in situ construction. Here, a NiS/NiFe 2 O 4 composite through a local metal−S coordination at the interface is reported, which is derived from phase reconstruction in the highly defective matrix. X-ray absorption fine structure confirms that long-range order is broken via the local metal−S coordination and, by using electron energy loss spectroscopy, the introduction of NiS/NiFe 2 O 4 interfaces during the irradiation of plasma energy is identified. Density functional theory (DFT) calculations reveal that in situ phase reconfiguration is crucial for synergistically reducing energetic barriers and accelerating reaction kinetics toward catalyzing the oxygen evolution reaction (OER). As a result; it leads to an overpotential of 230 mV @10 mA cm −2 for the OER and a half-wave potential of 0.81 V for the oxygen reduction reaction (ORR); as well as an excellent zinc−air battery (ZAB) performance with a power density of 148.5 mW cm −2 . This work provides a new compositing strategy in terms of fast phase reconstruction of bifunctional catalysts.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202110172.

Rare-Earth Metal–Organic Framework-Derived La2O3/NixPy Nanoparticles Embedded in Nitrogen-Doped Porous Carbon as Efficient Electrocatalysts for the Oxygen Evolution Reaction

“…The La 2 O 3 @NC, Ni x P y @NC, and La 2 O 3 /Ni x P y @NC catalysts showed obvious ESR signals around g = 2.003, indicating the presence of oxygen vacancies . The intensity of the ESR peaks of La 2 O 3 /Ni x P y @NC was significantly enhanced after the introduction of La 2 O 3 , demonstrating that the introduction of La 2 O 3 led to the generation of abundant oxygen vacancies in the La 2 O 3 /Ni x P y @NC catalysts and the increase of oxygen vacancies was beneficial to improving the oxygen storage and release capacity of the catalysts and enhancing the OER performance …”

Constructing Bridging Heterointerfaces of PtCo/Co9S8 for Enhancing Oxygen Electrocatalysis in Zn–Air Batteries

“…When the bimetallic sites of Pt and Co in PtCo alloy are considered as the real catalytic center, the RDS is the formation of the *OH intermediate, and the corresponding Δ G value is 1.15 eV. Notably, the RDS value of PtCo/Co 9 S 8 is less than that of PtCo alloy and Co 9 S 8 , and it is the minimum value when the bimetallic sites act as catalytic centers, which is consistent with the experimental measurement results . This result highlights that the enhancing oxygen electrocatalytic performance of PtCo/Co 9 S 8 should be benefiting from the critical role of the bridging Pt–Co–S coordination that arose from the heterointerfaces in the composites.…”

Abundant Dislocation Layered Double Hydroxides Synthesis by Molten Salt with Bound Water Boosting Oxygen Evolution

“…[21,28,31] Consequently, the obvious difference in D-NiFe LDH derived from the structure disorder caused by dislocation and tensile strain and the optimized electron structure could effectively improve their OER catalysis performance. [32] The electronic states and chemical composition of as-synthesized samples were further detected by the X-ray photo electron spectroscopy (XPS) and shown in Figure S20 (Supporting Information). The survey spectra illustrate C-NiFe LDH and D-NiFe LDH, composted by the same elements, Ni, Fe, and O (Figure S21, Supporting Information).…”