Cr‐Dopant Induced Breaking of Scaling Relations in CoFe Layered Double Hydroxides for Improvement of Oxygen Evolution Reaction. Issue 35 (15th July 2019)

• Record Type: Journal Article
• Authors: Wen, Lulu; Zhang, Xilin; Liu, Jieyu; Li, Xinyang; Xing, Changchang; Lyu, Xianjun; Cai, Weiping; Wang, Weichao; Li, Yue
• Is Part Of: Small. Volume 15:Issue 35(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-07-15
• Subjects: density functional theory -- doping -- electronic structure -- layered double hydroxide -- oxygen evolution reaction; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201902373
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Monodentate adsorption of oxygen intermediates results in a theoretical overpotential limit of ≈0.35 V for oxygen evolution reaction (OER), which causes the sluggish kinetics of the OER process. In this work, nonprecious chromium dopant is introduced into the self‐supported CoFe layered double hydroxides (LDHs) on nickel foam (Cr‐CoFe LDHs/NF) via a facile one‐step hydrothermal method, which exhibits a preeminent electrocatalytic activity toward the OER with an ultralow overpotential of 238 mV to obtain 10 mA cm −2 and a high stability after cyclic voltammetry for 5000 cycles in alkaline solution (1m KOH). Density functional theory (DFT) calculations unveil that Cr dopants as new active sites could improve the electron‐donation ability of the resultant Cr‐CoFe LDHs due to the smaller electronegativity of Cr in comparison with Fe and Co. Therefore, the scaling relation of adsorption energy among four oxygen intermediates is broken and consequently the OER performance is further promoted. This work provides a strategy to develop efficient metal layered double hydroxide OER catalysts. Abstract : Heteroatom‐doped CoFe layered double hydroxides are experimentally prepared and confirmed with high oxygen evolution reaction activity due to electronic tuning effects. Density functional theory calculations demonstrate that the smaller electronegativity of Cr than Co/Fe contributes to breaking up the scaling relationships of oxygen intermediates through tuning the adsorption toward OOH intermediates.