3D Hydrangea Macrophylla-like Nickel-Vanadium Metal-Organic Frameworks Formed by Self-Assembly of Ultrathin 2D Nanosheets for Overall Water Splitting

Junjun Lv; Panpan Liu; Fei Yang; Liwen Xing; Danni Wang; Xiao Chen; Hongyi Gao; Xiubing Huang; Yunfeng Lu; Ge Wang

doi:10.1021/acsami.0c11722

3D Hydrangea Macrophylla-like Nickel-Vanadium Metal-Organic Frameworks Formed by Self-Assembly of Ultrathin 2D Nanosheets for Overall Water Splitting

ACS Appl Mater Interfaces. 2020 Oct 28;12(43):48495-48510. doi: 10.1021/acsami.0c11722. Epub 2020 Oct 13.

Authors

Junjun Lv¹, Panpan Liu², Fei Yang¹, Liwen Xing¹, Danni Wang¹, Xiao Chen², Hongyi Gao¹, Xiubing Huang¹, Yunfeng Lu³, Ge Wang¹

Affiliations

¹ Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory of Function Materials for Molecule & Structure Construction, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China.
² Institute of Advanced Materials, Beijing Normal University, Beijing 100875, P. R. China.
³ Department of Materials Science and Engineering, University of California, Los Angeles, California 90034, United States.

PMID: 33050703
DOI: 10.1021/acsami.0c11722

Abstract

The development of highly efficient and low-cost bifunctional noble metal-free electrocatalysts for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is an effective strategy for improving efficiency. Herein, novel three-dimensional (3D) bimetallic metal-organic frameworks containing Ni and V with adjustable stoichiometry were synthesized on nickel foam successfully. Notably, Ni2V-MOFs@NF only require rather low overpotentials of 244 and 89 mV for the OER and HER, respectively, and expedites overall water splitting with 1.55 V at 10 mA cm^-2 with robust durability during the 80 h test. The high efficiency of the novel obtained electrocatalysts should be attributed to the particular morphological design of the two-dimensional (2D) ultrathin nanosheets self-assembling into a 3D nanoflower and the electronic structure regulation resulting from the synergetic interaction between nickel and vanadium. Subsequent theoretical calculations reveal the following conclusions: (I) the exceptional electronic conductivity of Ni2V-MOFs shows enhanced optimization as a result of electronic structure reconstruction, (II) the energy barrier reduction of the rate-limiting step is responsible for the enhanced dynamics of Ni2V-MOFs for the OER, and (III) the facilitation of the adsorption of H⁺ and H₂O plays a key role in progressing the HER catalytic activity of Ni2V-MOFs.

Keywords: bimetallic metal−organic frameworks; overall water splitting; self-assembly; theoretical calculation; three-dimensional structure.