Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/151915
Title: Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions
Authors: Liu, Peng
Chen, Bo
Liang, Caiwu
Yao, Wentao
Cui, Yuanzheng
Hu, Shengyu
Zou, Peichao
Zhang, Hua
Fan, Hong Jin
Yang, Cheng
Keywords: Engineering::Materials::Functional materials
Issue Date: 2021
Source: Liu, P., Chen, B., Liang, C., Yao, W., Cui, Y., Hu, S., Zou, P., Zhang, H., Fan, H. J. & Yang, C. (2021). Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions. Advanced Materials, 33(9), e2007377-. https://dx.doi.org/10.1002/adma.202007377
Journal: Advanced Materials
Abstract: The slow kinetics of oxygen evolution reaction (OER) causes high power consumption for electrochemical water splitting. Various strategies have been attempted to accelerate the OER rate, but there are few studies on regulating the transport of reactants especially under large current densities when the mass transfer factor dominates the evolution reactions. Herein, Nix Fe1- x alloy nanocones arrays (with ≈2 nm surface NiO/NiFe(OH)2 layer) are adopted to boost the transport of reactants. Finite element analysis suggests that the high-curvature tips can enhance the local electric field, which induces an order of magnitude higher concentration of hydroxide ions (OH- ) at the active sites and promotes intrinsic OER activity by 67% at 1.5 V. Experimental results show that a fabricated NiFe nanocone array electrode, with optimized alloy composition, has a small overpotential of 190 mV at 10 mA cm-2 and 255 mV at 500 mA cm-2 . When calibrated by electrochemical surface area, the nanocones electrode outperforms the state-of-the-art OER electrocatalysts. The positive effect of the tip-enhanced local electric field in promoting mass transfer is also confirmed by comparing samples with different tip curvature radii. It is suggested that this local field enhanced OER kinetics is a generic effect to other OER catalysts.
URI: https://hdl.handle.net/10356/151915
ISSN: 1521-4095
DOI: 10.1002/adma.202007377
Rights: This is the peer reviewed version of the following article: Liu, P., Chen, B., Liang, C., Yao, W., Cui, Y., Hu, S., Zou, P., Zhang, H., Fan, H. J. & Yang, C. (2021). Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions. Advanced Materials, 33(9), e2007377-. https://dx.doi.org/10.1002/adma.202007377, which has been published in final form at https://doi.org/10.1002/adma.202007377. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SPMS Journal Articles

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