@article{Tang2022, 
author = {Tang Tang and Zhe Jiang and Jun Deng and Shuai Niu and Ze-Cheng Yao and Wen-Jie Jiang and Lin-Juan Zhang and Jin-Song Hu},
title = {Constructing hierarchical nanosheet-on-microwire FeCo LDH@Co3O4 arrays for high-rate water oxidation},
year = {2022},
journal = {Nano Research},
volume = {15},
number = {12},
pages = {10021-10028},
keywords = {layered double hydroxides, oxygen evolution reaction, water splitting, electrocatalysts, hierarchical structures},
url = {https://www.sciopen.com/article/10.1007/s12274-022-5094-8},
doi = {10.1007/s12274-022-5094-8},
abstract = {Alkaline electrochemical water oxidation powered by renewable energies is a promising and environmentally friendly way to produce hydrogen. The industrial water electrolyzers are commonly operated at a high current density, calling for abundant and durable active sites to participate in. The rational design of hierarchically structured electrocatalysts is thus essential to industrial water electrolyzers. Herein, we develop a Fe3+ induced nanosizing strategy for fabricating such a hierarchical FeCo LDH@Co3O4 (LDH: layered double hydroxide) nanostructure array for high-rate water oxidation. Density functional theory (DFT) simulations indicate that the introduction of Fe3+ with a small ion radius and high electrical repulsion in the LDH layer distorted the LDH layer, resulting in a reduced nanosheet size and enabling the formation of a hierarchical structure. Such structure cannot be achieved without the participation of Fe3+ cations. Benefiting from the significantly enhanced electrochemical surface areas and charge/mass transport due to the hierarchical structure together with the boosted intrinsic activity by electronic modulation of Fe3+, such FeCo LDH@Co3O4 electrode can deliver an industrial-level current density of 1,000 mA·cm−2 at a small overpotential of 392 mV for water oxidation. When assembled in a water electrolyzer, it delivers a current density of 100 mA·cm−2 at a low operation voltage of 1.61 V. Powered by solar light, the electrolyzer demonstrates high solar-to-hydrogen efficiency of 18.15% with stable and reproducible photoresponse. These results provide new insights for constructing hierarchical nanostructures for advanced water oxidation and other diverse applications.}
}