A Universal Process: Self-Templated and Orientated Fabrication of XMoO4 (X: Ni, Co, or Fe) Nanosheets on MoO2 Nanoplates as Electrocatalysts for Efficient Water Splitting

Linjing Yang; Hui Liu; Ziqian Zhou; Yuke Chen; Guowei Xiong; Lili Zeng; Yunqie Deng; Xiaoli Zhang; Hong Liu; Weijia Zhou

doi:10.1021/acsami.0c08750

A Universal Process: Self-Templated and Orientated Fabrication of XMoO₄ (X: Ni, Co, or Fe) Nanosheets on MoO₂ Nanoplates as Electrocatalysts for Efficient Water Splitting

ACS Appl Mater Interfaces. 2020 Jul 29;12(30):33785-33794. doi: 10.1021/acsami.0c08750. Epub 2020 Jul 20.

Authors

Linjing Yang^{1

2}, Hui Liu¹, Ziqian Zhou^{1

2}, Yuke Chen², Guowei Xiong², Lili Zeng¹, Yunqie Deng¹, Xiaoli Zhang³, Hong Liu^{2

4}, Weijia Zhou^{1

2}

Affiliations

¹ Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong 510006, People's Republic of China.
² Shandong Collaborative Innovation Center of Technology and Equipements for Biological Diagnosis and Therapy, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan 250022, People's Republic of China.
³ School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, People's Republic of China.
⁴ State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China.

PMID: 32631054
DOI: 10.1021/acsami.0c08750

Abstract

Fabrication of superior nonprecious electrocatalysts is essential for water electrolysis. Herein, the epitaxial growth of the XMoO₄ (X = Ni, Co, Fe) nanosheets on the hexagonal MoO₂ nanoplates are carried out. The preoxidation of MoO₂ nanoplate is fatal to the epitaxial growth of a nanosheets array on MoO₂ nanoplates. The hierarchical heterostructure of the vertically aligned NiMo nanosheets on MoO₂ nanoplate (NiMo/MoO₂) is well-maintained in the process of in situ topotactic reduction transformation from NiMoO₄·xH₂O/MoO₂. Attributing it to the rich electroactive sites from nanosheets array, together with the intrinsic electrocatalytic performance of NiMo alloy, the as-engineered NiMo/MoO₂ as electrocatalyst exhibits admirable hydrogen evolution reaction (HER) activity with a small onset potential of -12 mV vs RHE (1 mA cm^-2) and a tafel value of 43.6 mV dec^-1 at alkaline media. Furthermore, the obtained CoMoO₄/MoO₂ possesses excellent oxygen evolution performance, which is verified by an ultralow overpotential of 230 mV@10 mA cm^-2, small Tafel slope (51 mV dec^-1), and robust durability. The developed NiMo/MoO₂ and CoMoO₄/MoO₂ electrocatalysts are assembled into an alkaline electrolyzer, which affords a cell potential of 1.51 V at 10 mA cm^-2, as well as outstanding operational durability, which is superior to the typically constructed 20 wt % Pt/C-RuO₂ system (1.59 V at 10 mA cm^-2). Hence, the universal strategy using MoO₂ nanoplates as Mo source and epitaxial substrate may be extended to explore and construct economical and superior Mo-based electrocatalysts for water electrolysis.

Keywords: CoMoO4/MoO2; NiMo/MoO2; epitaxial growth; hierarchical heterostructure; water electrolysis.