The Heterointerface between Fe₁/NC and Selenides Boosts Reversible Oxygen Electrocatalysis

Abstract

The rational design and construction of efficient and inexpensive bifunctional oxygen electrocatalysts are highly desirable for the development of rechargeable Zn–air batteries (ZABs). Although single‐atom Fe sites anchored on N‐doped carbon catalysts (Fe1/NC) ensure high oxygen reduction reaction activity, their unitary atomically dispersed active center faces difficult condition in catalyzing oxygen evolution reaction simultaneously. Herein, a composite catalyst containing heterointerface between Fe1/NC and selenides ((Fe,Co)Se2) is constructed. The obtained (Fe,Co)Se2@Fe1/NC exhibits extremely narrow potential gap of 0.616 V and remarkable stability in alkaline media, outperforming the benchmark catalysts (Pt/C+RuO2: 0.720 V). Experimental results and density functional theory calculations reveal that heterointerface between Fe1/NC and (Fe,Co)Se2 accelerates the electron transfer and provides more moderate adsorption sites, which endow (Fe,Co)Se2@Fe1/NC with extremely high bifunctional oxygen catalytic activity. This study not only provides a superior bifunctional catalyst for ZABs, but also enriches the application of single‐atom catalysts in multifunctional energy storage and conversion devices.

Inhibition of Zinc Dendrite Growth by WC-Cellulose Separators for High-Performance Zinc-Ion Batteries

“…Meanwhile, the corrosion potential of the WCCNF separator becomes more positive, suggesting the improved anticorrosion ability of the Zn anode enabled by the WCCNF separator. The inhibition of corrosion and hydrogen evolution can be attributed to the fact that the WC particles block ion aggregation and guide Zn ion flux distribution by preventing concentration polarization and decreasing the space charge near the Zn anode and surface barrier to improve the charge transport kinetics. , Thus, the WCCNF separator brings higher ion-charge transport, as verified by EIS (Figure c). Furthermore, the Zn∥Ti half cell using the WCCNF separator exhibits a more stable charge–discharge cycling performance with a Coulombic efficiency of 98.7%, while the CNF separator leads to serious fluctuation of Coulombic efficiency in the Zn∥Ti cell after several cycles, due to its poor ability to inhibit surface corrosion, water-induced side reactions and Zn dendrite growth on the electrode surface.…”

Sustainable zinc–air battery chemistry: advances, challenges and prospects

“…The nanocomposite strategy provides an effective solution to construct hybrid catalysts, which can overcome the inherent disadvantages of single-function catalysts. 114,115 Different from mechanically mixed Pt/C + Ir(Ru)O 2 , the interfacial coupling effects between two components effectively reduce the reaction barrier for the ORR and OER simultaneously, showing high bifunctional catalytic activity. For example, Fu and coworkers coupled metallic Co islands (Co 0 ) with high OER activity and Co-N-C (Co 2+ and Co 3+ ) nanosheets with excellent ORR performance, obtaining bifunctional Co/Co-N-C catalysts.…”

“…Recently, Lei's group constructed a hybrid catalyst containing a heterointerface between selenide and Fe 1 /NC support. 115 The newly formed heterointerface between (Fe,Co)Se 2 and Fe 1 /NC greatly promoted the electron transfer and provided more moderate adsorption sites, displaying extremely high bifunctional activity with a DE of 0.616 V. Similarly, Lin and colleagues reported a nanocomposite strategy to integrate highly crumpled MoS 2 nanospheres with an atomic Fe-N-C layer, obtaining a core-shell MoS 2 @Fe-N-C nanosphere catalyst with abundant interfaces. 118 The atomic Fe-N-C shell efficiently protected the MoS 2 core from corrosion.…”

Insight on Atomically Dispersed Cu Catalysts for Electrochemical CO2 Reduction

“…However, AD Cu catalysts with single coordination environment are expected to overcome this shortcoming. , Moreover, the ECO 2 R reaction is a surface electrode reaction, and AD Cu catalysts have completely exposed active sites to provide space and bonding electrons for the adsorption of reactants in favor of better catalytic activity. , Furthermore, ECO 2 R involves complex multielectron transfer and multipath reaction. The AD Cu catalysts with well-defined active sites also provide an ideal platform for studying its reaction mechanism. − Most importantly, besides selectively producing C 1 products (CO, CH 4 , and CH 3 OH), AD Cu catalysts can show good catalytic activity and selectivity for C 2+ products (C 2 H 4 , C 2 H 5 OH, and CH 3 COCH 3 ), which is not reported in other AD metal catalysts.…”