Robust wrinkled MoS ₂ /N-C bifunctional electrocatalysts interfaced with single Fe atoms for wearable zinc-air batteries

Abstract

The ability to create highly efficient and stable bifunctional electrocatalysts, capable of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the same electrolyte, represents an important endeavor toward high-performance zinc-air batteries (ZABs). Herein, we report a facile strategy for crafting wrinkled MoS2/N-doped carbon core/shell nanospheres interfaced with single Fe atoms (denoted MoS2@Fe-N-C) as superior ORR/OER bifunctional electrocatalysts for robust wearable ZABs with a high capacity and outstanding cycling stability. Specifically, the highly crumpled MoS2 nanosphere core is wrapped with a layer of single-Fe-atom-impregnated, N-doped carbon shell (i.e., Fe-N-C shell with well-dispersed FeN4 sites). Intriguingly, MoS2@Fe-N-C nanospheres manifest an ORR half-wave potential of 0.84 V and an OER overpotential of 360 mV at 10 mA⋅cm−2. More importantly, density functional theory calculations reveal the lowered energy barriers for both ORR and OER, accounting for marked enhanced catalytic performance of MoS2@Fe-N-C nanospheres. Remarkably, wearable ZABs assembled by capitalizing on MoS2@Fe-N-C nanospheres as an air electrode with an ultralow area loading (i.e., 0.25 mg⋅cm−2) display excellent stability against deformation, high special capacity (i.e., 442 mAh⋅g−1Zn), excellent power density (i.e., 78 mW⋅cm−2) and attractive cycling stability (e.g., 50 cycles at current density of 5 mA⋅cm−2). This study provides a platform to rationally design single-atom-interfaced core/shell bifunctional electrocatalysts for efficient metal-air batteries.

Metal-coordinated porous polydopamine nanospheres derived Fe 3N-FeCo encapsulated N-doped carbon as a highly efficient electrocatalyst for oxygen reduction reaction

“…As the growing deterioration of environmental issues stems from the intensified utilization/exploration of fossil fuels, the development of clean and sustainable energy conversion and storage techniques, has garnered worldwide scientific and industrial attention. The oxygen reduction reaction (ORR) is a critical half-reaction involved in renewable energy conversion and storage devices, such as fuel cells and Zn-air batteries [1][2][3]. Nonetheless, the sluggish ORR kinetics at the cathode leads to insufficient overall energy conversion efficiency, thus numerous endeavors have been made to boost ORR kinetics.…”

Pyrolysis-free synthesis of single-atom cobalt catalysts for efficient oxygen reduction

“…1–5 In particular, as the most important electrode process in fuel cells and metal–air batteries, the oxygen reduction reaction (ORR) has been the research hotspot in the past few decades. 6–10 To date, platinum (Pt)-based materials have been widely recognised as state-of-the-art ORR electrocatalysts. 11–14 However, the inherent drawbacks of prohibitive cost, small reserves and poor stability have greatly hampered their widespread applications.…”

Decoupling layer metal–organic frameworks via ligand regulation to achieve ultra-thin carbon nanosheets for oxygen reduction electrocatalysis

“…3b), proving a higher degree of carbon graphitization after ligand regulation, which greatly promotes the electron transfer process of the ORR. 32,33 Fig. 3c and d show the change of the N element while half of the nitrogen source in the Zn(BIM) MOF precursor was replaced with 2-MIM.…”