NiO/CoN Porous Nanowires as Efficient Bifunctional Catalysts for Zn–Air Batteries

Abstract

The development of highly efficient bifunctional catalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is crucial for improving the efficiency of the Zn-air battery. Herein, we report porous NiO/CoN interface nanowire arrays (PINWs) with both oxygen vacancies and a strongly interconnected nanointerface between NiO and CoN domains for promoting the electrocatalytic performance and stability for OER and ORR. Extended X-ray absorption fine structure spectroscopy, electron spin resonance, and high-resolution transmission electron microscopy investigations demonstrate that the decrease of the coordination number for cobalt, the enhanced oxygen vacancies on the NiO/CoN nanointerface, and strongly coupled nanointerface between NiO and CoN domains are responsible for the good bifunctional electrocatalytic performance of NiO/CoN PINWs. The primary Zn-air batteries, using NiO/CoN PINWs as an air-cathode, display an open-circuit potential of 1.46 V, a high power density of 79.6 mW cm, and an energy density of 945 Wh kg. The three-series solid batteries fabricated by NiO/CoN PINWs can support a timer to work for more than 12 h. This work demonstrates the importance of interface coupling and oxygen vacancies in the development of high-performance Zn-air batteries.

Narrow-bandgap Nb2O5 nanowires with enclosed pores as high-performance photocatalyst

“…Among the many varieties of 1D nanostructures, porous nanowires are particularly interesting, not only for the unique porous structure and physical chemical properties, but also for their outstanding performance in optics and electronics [15][16][17][18][19][20][21][22][23]. So far, many groups have reported the growth of porous 1D semiconductor nanostructures and studied their exceptional performance, such as porous ZnO nanowires with superior photocatalytic activity [24], CdS nanosponges showing high activity for RhB photo-degradation under visible light due to the accessibility of both inner and outer surfaces through the pores in the walls [25], porous TiO 2 nanotubes with improved photocatalytic efficiency due to their larger specific surface areas [26], porous In 2 O 3 nanowires with excellent gas sensing properties to H 2 S benefiting from surface adsorption and the sulfuration [27], porous SnO 2 nanowire bundles consisting of interconnected nano-crystallites with a remarkable photocatalytic effect for the degradation of RhB and a high de-lithiation capacity [15], and porous Co 3 O 4 nanowires with high sensitivity to carbon monoxide because porous structure increases the surface reactive sites and facilitates the diffusion of target gases [28].…”

Oxygen Vacancies Dominated NiS2/CoS2 Interface Porous Nanowires for Portable Zn–Air Batteries Driven Water Splitting Devices

“…Furthermore, ESR spectra were measured to illustrate the vacancies in the NiS 2 /CoS 2 NWs, NiS 2 /CoS 2 -O NWs, and NiCo 2 O 4 NWs (Figure 2e). [25,31] The electrolyte should be saturated with O 2 before the measurement to avoid the oxygen created on the surface of the catalysts dissolved in the electrolyte. A small amount of sulfur vacancies are found in NiS 2 /CoS 2 NWs due to their weak ESR signal.…”

“…[12][13][14] However, their low abundance and high cost limit their large-scale applications in energy conversion and storage devices. [21][22][23][24][25] One of promising material systems is transition metal sulfides with controlled surface and interface tuning [26][27][28][29][30] such as high-index faceted sulfides, [28] metallic sulfides, [29] and interface sulfides [30] for catalyzing OER. [21][22][23][24][25] One of promising material systems is transition metal sulfides with controlled surface and interface tuning [26][27][28][29][30] such as high-index faceted sulfides, [28] metallic sulfides, [29] and interface sulfides [30] for catalyzing OER.…”

“…Figure 4a shows the schematic fabrication of rechargeable portable Znair battery. As shown in Figure 4b, the rechargeable portable Zn-air battery using NiS 2 /CoS 2 -O NWs as the air-cathode shows a high open-circuit voltage of ≈1.49 V, much higher than those of recently reported Co 4 N/CNW/CC, [52] NCNF-1000, [53] and NiO/CoN PINWs [25] based solid Zn-air batteries. Then, the solid electrolyte was prepared according to our previous work.…”

Strong Electronic Interaction in Dual‐Cation‐Incorporated NiSe2 Nanosheets with Lattice Distortion for Highly Efficient Overall Water Splitting

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focuses on exploration of efficient electrocatalysts that can overcome the sluggish kinetics and accelerate the evolution rates of H 2 and O 2 at low overpotentials. [11,12] In this content, the development of bifunctional catalysts which are highly active for both HER and OER in the same medium is highly desirable for overall water splitting.Accordingly, great efforts have been paid to developing bifunctional electrocatalysts based on transition metal nanomaterials and their derivatives, including metal oxides or hydroxides, [13,14] metal chalcogenides, [15][16][17] metal nitrides, [18,19] and metal phosphides. However, most of the recently developed HER and OER catalysts work in either acidic or alkaline medium.

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