A facile sequential ion exchange strategy to synthesize CoSe2/FeSe2 double-shelled hollow nanocuboids for the highly active and stable oxygen evolution reaction

• Published in: Nanoscale Vol. 11; no. 22; pp. 10738 - 10745
• Main Authors: Xu, Chunyang, Li, Qinghao, Shen, Junling, Yuan, Ze, Ning, Jiqiang, Zhong, Yijun, Zhang, Ziyang, Hu, Yong
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 14.06.2019
• Subjects: Chemical synthesis; Electrocatalysts; Ion exchange; Iron; Noble metals; Oxygen evolution reactions; Rare earth compounds; Rare earth elements; Selenides; Selenium; Transition metals
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c9nr02599e

Transition metal-based nanostructures have been considered as promising substitutes for rare-earth metal oxide electrocatalysts toward the oxygen evolution reaction (OER). Herein, we report for the first time on a novel multicomponent metal selenide electrocatalyst based on CoSe2/FeSe2 double-shelled hollow nanocuboids (CoSe2/FeSe2 DS-HNCs) with the highly oxidative Co3+ species, which is synthesized via a facile sequential ion exchange strategy. The solid Co-precursor nanocuboids are first converted into the intermediate Co2[Fe(CN)6] with a mesoporous and double-shelled hollow structure produced through a facile ligand exchange at room temperature, and then the final CoSe2/FeSe2 DS-HNCs are obtained by a subsequent Se ion exchange reaction. The intermediate product of Co2[Fe(CN)6] plays an important role not only in constructing a double-shelled hollow structure but also in providing the Fe source for the growth of the final multicomponent metal selenides. Benefiting from the nanosized double-shelled hollow structure and mesoporous double-metal selenide shells with the highly oxidative Co3+ species, the as-prepared CoSe2/FeSe2 DS-HNCs exhibit superior OER performance to state-of-the-art metal selenides, including a small overpotential of 240 mV at a current density of 10 mA cm−2 and the excellent electrochemical durability over 50 h. This work opens up a new avenue towards developing highly active multicomponent noble-metal-free electrocatalysts.