Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions
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...
| Main Authors: | , , , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2021
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/151915 |
| _version_ | 1826125989843828736 |
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| author | Liu, Peng Chen, Bo Liang, Caiwu Yao, Wentao Cui, Yuanzheng Hu, Shengyu Zou, Peichao Zhang, Hua Fan, Hong Jin Yang, Cheng |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Liu, Peng Chen, Bo Liang, Caiwu Yao, Wentao Cui, Yuanzheng Hu, Shengyu Zou, Peichao Zhang, Hua Fan, Hong Jin Yang, Cheng |
| author_sort | Liu, Peng |
| collection | NTU |
| description | 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. |
| first_indexed | 2024-10-01T06:45:27Z |
| format | Journal Article |
| id | ntu-10356/151915 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T06:45:27Z |
| publishDate | 2021 |
| record_format | dspace |
| spelling | ntu-10356/1519152023-02-28T19:49:15Z Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions Liu, Peng Chen, Bo Liang, Caiwu Yao, Wentao Cui, Yuanzheng Hu, Shengyu Zou, Peichao Zhang, Hua Fan, Hong Jin Yang, Cheng School of Physical and Mathematical Sciences Engineering::Materials::Functional materials Electrochemical Water Splitting Oxygen Evolution Reaction 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. Accepted version 2021-07-08T08:44:16Z 2021-07-08T08:44:16Z 2021 Journal 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 1521-4095 https://hdl.handle.net/10356/151915 10.1002/adma.202007377 33511663 2-s2.0-85099852147 9 33 e2007377 en Advanced Materials 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. application/pdf |
| spellingShingle | Engineering::Materials::Functional materials Electrochemical Water Splitting Oxygen Evolution Reaction Liu, Peng Chen, Bo Liang, Caiwu Yao, Wentao Cui, Yuanzheng Hu, Shengyu Zou, Peichao Zhang, Hua Fan, Hong Jin Yang, Cheng Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions |
| title | Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions |
| title_full | Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions |
| title_fullStr | Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions |
| title_full_unstemmed | Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions |
| title_short | Tip-enhanced electric field : a new mechanism promoting mass transfer in oxygen evolution reactions |
| title_sort | tip enhanced electric field a new mechanism promoting mass transfer in oxygen evolution reactions |
| topic | Engineering::Materials::Functional materials Electrochemical Water Splitting Oxygen Evolution Reaction |
| url | https://hdl.handle.net/10356/151915 |
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