Fe‐Ni‐Mo Nitride Porous Nanotubes for Full Water Splitting and Zn‐Air Batteries

Abstract

hydrogen fuel. To achieve high energy storage and conversion efficiencies, highperformance electrocatalysts are required. Precious metals such as Pt have shown high activity toward the hydrogen evolution reaction (HER) and the oxygen reduction reaction (ORR), while RuO 2 and IrO 2 have shown excellent activity toward the oxygen evolution reaction (OER). [1,2] Nevertheless, their high cost and low natural abundance have significantly limited the large-scale utilization of those precious electrocatalysts. Therefore, many efforts have been made to explore the nonprecious metal based electrocatalysts for full water splitting and metal-air batteries. Furthermore, to further reduce the cost for energy storage and conversion devices, it is highly desirable to develop trifunctional electrocatalysts that can catalyze the HER, ORR, and OER simultaneously in the same electrolyte.Recently, nonprecious transition-metal compound nanostructures with various morphologies have been reported for catalyzing the HER, OER, and/or ORR. Among these electrocatalysts, the nanotube (NT)-based ones with open ends and/ or porous features have attracted much interest because of their hollow interiors, porous characteristics, and large surface area, which greatly facilitate the exposure of active sites to the electrolyte, the quick diffusion of electrolyte into the active species, and the quick release of the thus-formed hydrogen and oxygen bubbles from the catalyst surface. Typically, tubular nanostructures, including Mo 2 C, [3,4] MoS 2 , [5,6] MoSe 2 , [7] Ni-Mo nitride, [8] Ni-Co selenide, [9] Ni-Co hydroxide, [10] Ni-Co nitride, [11] MoS 2 /SnO 2 , [12] and MoO x /MoS 2 [13] for catalyzing the HER, FeOOH/CeO 2 , [14] FeOOH/Co/FeOOH, [15] CoO x , [16] and Ni-Co phosphide [17] for catalyzing the OER, and Pt-Co/CN x , [18] PtAuCu, [19] Co@Co 3 O 4 /carbon nanotubes (CNTs), [20] CoSe 2 / CNTs, [21] NiCo/CNTs, [22] and Co x Mn 3−x O 4 , [23] for catalyzing the OER and ORR have been reported. Despite the advances in the transition-metal nanotube electrocatalysts for the HER, OER, and ORR, high-performance trifunctional electrocatalysts based on transition-metal nanotubes that can catalyze the HER, OER, and ORR simultaneously in the same electrolyte have rarely been reported.Besides controlling the morphology, tuning the electronic structure of the electrocatalysts through introducing heteroatoms into the catalyst host or designing multimetal catalysts has been considered as an important and efficient method for increasing the activities of electrocatalysts. [24][25][26][27][28][29] Among the multimetal catalysts mentioned above, Ni-Fe bimetal-based High-performance catalysts are required in various energy storage and conversion systems. In this work, hierarchical Ni-Fe-Mo trimetal nitride nanotubes (NTs) as highly efficient, low-cost, robustly stable, multifunctional catalysts through room-temperature Fe incorporation and subsequent thermal treatment for full water splitting and Zn-air batteries are fabricated. The two-electrode electrolyzer ...

Dynamic electrocatalyst with current-driven oxyhydroxide shell for rechargeable zinc-air battery

“…Previously, limitations in the availability and rechargeability of oxygen electrocatalysts have hindered their popularization, but blooming efforts on exploring suitable and durable candidates to catalyze cathode reactions have led to the recent rejuvenation of this century-old technology [4][5][6] . As such, huge families of materials have been investigated, including metals, alloys, oxides, sulfides, nitrides, phosphides, and their derived composites with carbon 2,[7][8][9][10][11][12][13][14][15][16][17][18] . To this day, exploration for ideal bifunctional electrocatalysts remains to be the research mainstream, but attention is shifting toward understanding the relationship between battery performance and physiochemical properties of electrocatalysts for performance breakthrough.…”

“…As a proof of this concept, a bimetal nitride, (Co, Fe) 3 N, is selected as a typical representation for metal-based materials with two major considerations. First, based on both experimental and theoretical evidences, metal nitride intrinsically exhibits metallic nature with high electrical conductivity 17,19,27,28 .…”

Cobalt Phosphide Ultrathin and Freestanding Sheets Prepared through Microwave Chemical Vapor Deposition: A Highly Efficient Oxygen Evolution Reaction Catalyst

“…The required overpotential (by CoP) to reach 10 mA cm −2 is much lower than that required by Co‐LDH (295 mV), Co 3 O 4 (388 mV), and RuO 2 (340 mV). Fascinatingly, such OER activity of CoP nanosheets is outstanding among the recently reported cobalt phosphide‐based OER catalysts including CoP nanosheets (361 mV), CoP nanosheets/C (292 mV), CoP nanorods (320 mV), CoP polyhedrons (400 mV), Phosphate modified CoP nanorods (310 mV), CoP nanoneedles array (281 mV), CoP film (345 mV), and compares favorably with many excellent earth abundant OER electrocatalysts such as FeNi 3 N particles/N doped graphene (258 mV for 20 mA cm −2 ), N,B doped Co 3 C spheres (358 mV), NiMoN nanowire array (238 mV), Ni−Fe‐MoN nanotubes (228 mV), and others in summarized in Tables S1. Of note, both CoP nanosheets and Co 3 O 4 were prepared at the same temperature (300 °C), thus the poor OER activity of Co 3 O 4 excludes any favorable effect of the thermal treatment from the boosted OER activity of CoP nanosheets.…”

Preparation of bimetal-based FeNi-N/C catalyst and its electrocatalytic oxygen reduction performance

“…For instance, Li et al [33] pointed out that the addition of Cu in the Fe-N-C catalyst can promote the interaction between the metal Fe and N and increase the content of the surface active sites of the catalyst, leading to the improvement of the performance of the catalyst. So far, the FeNi-N/C bimetallic catalysts are mostly studied with their oxides, and the preparation method is more complicated [38][39][40][41]. Independent of the mechanism or nature of the active site, previous researches [33,[42][43][44] have shown that the nature and amount of metal, pyrolysis temperature, carbon support, N-rich polymer and ligand structure are key parameters determining the ORR activity of the catalyst.…”