Ultrathin metal-organic framework array for efficient electrocatalytic water splitting.

ABSTRACT: Two-dimensional metal-organic frameworks represent a family of materials with attractive chemical and structural properties, which are usually prepared in the form of bulk powders. Here we show a generic approach to fabricate ultrathin nanosheet array of metal-organic frameworks on different substrates through a dissolution-crystallization mechanism. These materials exhibit intriguing properties for electrocatalysis including highly exposed active molecular metal sites owning to ultra-small thickness of nanosheets, improved electrical conductivity and a combination of hierarchical porosity. We fabricate a nickel-iron-based metal-organic framework array, which demonstrates superior electrocatalytic performance towards oxygen evolution reaction with a small overpotential of 240?mV at 10?mA?cm^-2, and robust operation for 20,000?s with no detectable activity decay. Remarkably, the turnover frequency of the electrode is 3.8?s^-1 at an overpotential of 400?mV. We further demonstrate the promise of these electrodes for other important catalytic reactions including hydrogen evolution reaction and overall water splitting.

SUBMITTER: Duan J 

PROVIDER: S-EPMC5465318 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature