Hollow Nanocages of NixCo1−xSe for Efficient Zinc–Air Batteries and Overall Water Splitting

Abstract

HIGHLIGHTS • A facile strategy for fabricating Ni x Co 1−x Se hollow nanocages was developed, and the formation mechanism was well explained. • Ni 0.2 Co 0.8 Se outperformed a Pt/C + RuO 2 catalyst in rechargeable and all-solid-state Zn-air battery tests, as well as in overall water splitting. • The hydrogen adsorption onto Ni x Co 1−x Se was simulated, and Gibbs free energies were calculated.

Bifunctional Oxygen Electrocatalyst of Mesoporous Ni/NiO Nanosheets for Flexible Rechargeable Zn–Air Batteries

“…To improve the performance of Zn-air batteries, oxygen reduction and evolution reaction (ORR/ OER) processes are required, where these reactions influence the charging-discharging progress [10][11][12]. Although Pt/Ir-based catalysts can perform well for either the ORR or OER, their application prospect is limited owing to the high cost and instability of these catalysts in commercial applications [13,14]. Hence, there is an apparent urgency for exploring highly efficient non-noble metal electrocatalysts with rapid ORR/OER kinetics and superior overall performance.…”

Bifunctional Electrocatalysts Based on Mo-Doped NiCoP Nanosheet Arrays for Overall Water Splitting

“…Electrochemical water splitting, consisting of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), is a promising approach to generate sustainable H 2 from water [1][2][3][4]. Even though Ir-/Ru-based oxides and Pt catalysts show excellent electrocatalytic performances for OER and HER, the high cost and the scarcity of these noble catalysts greatly hinder their practical applications [5][6][7][8]. When different electrodes are used for a single water-splitting device, the incompatibility and different reaction kinetics in OER and HER may lead to inferior efficiency [9][10][11].…”

Heterostructure and Oxygen Vacancies Promote NiFe2O4/Ni3S4 toward Oxygen Evolution Reaction and Zn‐Air Batteries

“…Figure 4a demonstrates the schematic diagram of the rechargeable ZABs, in which a proof-of-concept was executed by using NiFe 2 O 4 /Ni 3 S 4 as the air-cathode catalyst, the Zn plate as the anode, and 6.0 M KOH + 0.2 M Zn(OAc) 2 as the electrolyte. The reactions between the anode and the cathode during charging and discharging of the ZAB can be described as follows: [1,4,55] Anode :…”

“…The ever-growing global fossil fuel consumption and associated serious environmental pollution issue demand sustainable energy supply, where zinc-air batteries and water splitting devices are highly considered as promising next-generation energy storage and conversion techniques. [1,2] Rechargeable zinc air batteries (ZABs) hold the great advantages including high theoretical energy density, low cost, environmental friendliness, and intrinsic safety nature, [3,4] while electrochemical water splitting into H 2 and O 2 has been widely regarded as one of the most promising strategies to effectively use renewable energy from harvest to redistribution. [5,6] Unfortunately, the practical performance of both rechargeable zinc air batteries and electrochemical water splitting device is significantly hindered by the key electrochemical process namely oxygen evolution reaction (OER) occurring at the electrode, as an energy barrier needs to be overcome in OER to accomplish the 4-electron transfer process and forming the covalent OÀ O bond.…”

“…[11] Unfortunately, the scarcity in earth and high costs of these noble metals significantly hamper their large-scale applications. [12] Recently, non-noble-metal based catalysts including porous carbon materials, [13] perovskites, [14] transition metal oxides, [15] hydroxides, [16] selenides, [4] and their composites [17] have been attracting intense interests to be alternatives. Among them, transition metal oxides and chalcogenides are arousing increasing attentions for OER.…”