Transition metal alloy integrated tubular carbon hybrid nanostructure for bifunctional oxygen electrocatalysis

• Published in: Electrochimica acta Vol. 348; p. 136274
• Main Authors: Samanta, Arpan, Ghatak, Arnab, Bhattacharyya, Somnath, Raj, C. Retna
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 10.07.2020; Elsevier BV
• Subjects: Carbon; Carbon content; Catalysts; Chemical synthesis; Electrocatalysis; Electrocatalysts; Intermetallic compounds; Melamine; Metal air batteries; Nanostructure; Nickel; Nitrogen; Open circuit voltage; Oxygen electrocatalyst; Oxygen evolution reactions; Rechargeable batteries; Self-assembly; Transition metal alloys; Tubular carbon nanoarchitecture; Ultrafines; Zinc-oxygen batteries; Zn-air battery; Electrocatalysis; Zn-air battery; Tubular carbon nanoarchitecture; Oxygen electrocatalyst
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.136274

Synthesis of cost-effective, robust, and efficient bifunctional electrocatalyst for the development of rechargeable Zn-air batteries (ZAB) is of considerable interest. Herein, we demonstrate the synthesis of NiCo alloy integrated nitrogen-doped tubular carbon (TC) nanostructure (NiCo–N-TC) using metal-organic self-assembly of M(II)-melamine-dipicolinic acid (DPA) (M: Ni(II), Co(II)). The NiCo alloy particles of as-synthesized NiCo–N-TC catalyst are confined at the tip like a cork. The as-synthesized catalyst was structurally engineered by acid treatment. The engineered catalyst (NiCo–N-TC-H) has an open-head hollow nanoarchitecture with uniform distribution of ultrafine NiCo alloy particles on the TC framework. The NiCo–N-TC-H catalyst follows desired 4-electron pathway for the electroreduction of oxygen in both alkaline and acidic pH. It has outstanding bifunctional electrocatalytic activity towards oxygen reduction and oxygen evolution reaction in alkaline electrolyte with a very low potential gap (ΔE) of 0.74 V. Acid-treatment-induced increase in surface area, and graphitic-N and carbon content facilitates the overall bifunctional activity. The bifunctional activity of NiCo–N-TC-H is successfully utilized for the development of rechargeable ZAB. It has long cycling stability and delivers high open circuit voltage (1.54 V), power density of 148.8 mW cm−2, and high voltaic efficiency. [Display omitted]