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Aluminum‐Tailored Energy Level and Morphology of Co 3− x Al x O 4 Porous Nanosheets toward Highly Efficient Electrocatalysts for Water Oxidation
Author(s) -
Wang Xianfu,
Sun Pengfei,
Lu Haoliang,
Tang Kai,
Li Qun,
Wang Chao,
Mao Zeyang,
Ali Tariq,
Yan Chenglin
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201804886
Subject(s) - materials science , morphology (biology) , porosity , electrocatalyst , nanotechnology , chemical engineering , aluminium , chemistry , metallurgy , electrochemistry , electrode , composite material , engineering , genetics , biology
Abstract Tuning energy levels plays a crucial role in developing cost‐effective, earth‐abundant, and highly active oxygen evolution catalysts. However, to date, little attention has been paid to the effect of using heteroatom‐occupied lattice sites on the energy level to engineer electrocatalytic activity. In order to explore heteroatom‐engineered energy levels of spinel Co 3 O 4 for highly‐effective oxygen electrocatalysts, herein Al atoms are directly introduced into the crystal lattice by occupying the Co 2+ ions in the tetrahedral sites and Co 3+ ions in the octahedral sites (denoted as Co 2+ Td and Co 3+ Oh , respectively). Experimental and theoretical simulations demonstrate that Al 3+ ions substituting Co 2+ Td and Co 3+ Oh active sites, especially Al 3+ ions occupying the Co 2+ Td sites, optimizes the adsorption, activation, and desorption features of intermediate species during oxygen evolution reaction (OER) processes. As a result, the optimized Co 1.75 Al 1.25 O 4 nanosheet exhibit unprecedented OER activity with an ultralow overpotential of 248 mV to deliver a current of 10 mA cm –2 , among the best Co‐based OER electrocatalysts. This work should not only provide fundamental understanding of the effect of Al‐occupied different Co sites in Co 3–x Al x O 4 composites on OER performance, but also inspire the design of low‐cost, earth‐abundant, and high‐active electrocatalysts toward water oxidation.