Efficient Hydrogen Evolution Activity and Overall Water Splitting of Metallic Co4N Nanowires through Tunable d-Orbitals with Ultrafast Incorporation of FeOOH

Yuwen Hu; Hao Yang; Junjie Chen; Tuzhi Xiong; M-Sadeeq Jie Tang Balogun; Yexiang Tong

doi:10.1021/acsami.8b20717

Efficient Hydrogen Evolution Activity and Overall Water Splitting of Metallic Co₄N Nanowires through Tunable d-Orbitals with Ultrafast Incorporation of FeOOH

ACS Appl Mater Interfaces. 2019 Feb 6;11(5):5152-5158. doi: 10.1021/acsami.8b20717. Epub 2019 Jan 29.

Authors

Yuwen Hu¹, Hao Yang¹, Junjie Chen¹, Tuzhi Xiong², M-Sadeeq Jie Tang Balogun², Yexiang Tong¹

Affiliations

¹ MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-Carbon Chemistry & Energy Conservation of Guangdong Province, School of Chemistry , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China.
² College of Materials Science and Engineering , Hunan University , Changsha 410082 , Hunan , People's Republic of China.

PMID: 30644716
DOI: 10.1021/acsami.8b20717

Abstract

Cobalt nitride electrocatalysts have been investigated and proven to show excellent oxygen evolution reaction activity owing to their excellent metallic properties, but their hydrogen evolution reaction (HER) properties are rarely reported because of their unsatisfactory molecular energy level, especially the d-orbital. Herein, taking Co₄N as a case study, we tune the d-orbital of metallic Co₄N nanowires via rapid formation of iron oxyhydroxide (FeOOH). Experimental analyses show that FeOOH@Co₄N/SSM exhibits excellent HER catalytic activity with considerable low onset overpotential (22 mV), small Tafel slope (34 mV dec^-1), and excellent stability at current densities ranging from 20 to 100 mA cm^-2. Additionally, theoretical assessments display that the hybridization of Co₄N with FeOOH is beneficiary for optimizing and promoting the free energy of H adsorption due to the tuning of d-orbital. An overall water-splitting device assembled based on bifunctional FeOOH@Co₄N/SSM delivers an onset potential of 1.48 V with excellent stability up to 4 days. This shows a new strategy for designing a high-performance water-splitting device based on cobalt-based electrocatalysts.

Keywords: Co4N; FeOOH; d-orbital; hybridization; hydrogen evolution reaction.