Ultrathin Two-Dimensional Polyoxometalate-Based Metal-Organic Framework Nanosheets for Efficient Electrocatalytic Hydrogen Evolution.

Autor: Wang L; College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, P. R. China., Wang A; College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, P. R. China., Xue ZZ; College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, P. R. China., Hu JX; College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, P. R. China., Han SD; College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, P. R. China., Wang GM; College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, P. R. China.
Jazyk: angličtina
Zdroj: Inorganic chemistry [Inorg Chem] 2022 Nov 14; Vol. 61 (45), pp. 18311-18317. Date of Electronic Publication: 2022 Oct 28.
DOI: 10.1021/acs.inorgchem.2c03431
Abstrakt: The rational design of 2D polyoxometalate-based metal-organic framework (POMOF) nanosheets on a conductive substrate as a self-supporting electrode is highly attractive but a great challenge. Herein is the first demonstration of POMOF nanopillar arrays consisting of 2D nanosheets as a self-supported electrode for the hydrogen evolution reaction (HER) in acidic conditions. Single-crystal X-ray analysis reveal that our as-prepared 2D [Co 2 (TIB) 2 (PMo 12 O 40 )]·Cl·4H 2 O [named CoMo-POMOF; TIB = 1,3,5-tris(1-imidazoly)benzene] crystalline materials are connected by Co-α-Keggin polymolybdate units act as secondary building blocks and TIB as the organic ligands. The 2D CoMo-POMOF nanosheets were successfully arrayed on a conductive nickel foam substrate by a facile CoO nanorod template-assisted strategy. Remarkably, the CoMo-POMOF nanopillar arrays demonstrate superior electrocatalytic performance toward the HER with an overpotential of 137 mV and Tafel slope of 59 mV dec -1 at 10 mA cm -2 , which are comparable to those of state-of-the-art POMOF-based electrocatalysts. Density-functional theory (DFT) calculations demonstrate that the exposed bridging oxygen active sites (O a ) of Co-α-Keggin polymolybdate units in CoMo-POMOF optimize the Gibbs free energy of H* adsorption (Δ G H* = -0.11 eV) and increase the intrinsic HER activity.
Databáze: MEDLINE
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