Abstract
Two-dimensional (2D) metal–organic framework (MOF) based heterostructures will be greatly advantageous to enhance catalytic performance because they increase the contact surface and charge transfer. Herein, a novel 2D heterostructure named CeO2@NiFe-MOFs, in which monolayer NiFe-MOFs is coordinated with ceria (CeO2) to improve catalytic and stability performance, is successfully constructed by the strategy of in situ growth on the surface of ultrathin CeO2 nanosheets being functionalized with monolayer carboxylic acid groups. The 2D heterostructure possesses a sandwich structure, where monolayer NiFe-MOFs are coordinated to both the top and bottom surface of CeO2 nanosheets via joining carboxylic acid groups. In particular, CeO2 with robust coordination plays a significant role in the anchoring of carboxylic acid groups and binding strength of heterostructures. The 2D CeO2@NiFe-MOF heterostructure with a joint effect of metal–ligand coordination not only presents good structural stability but also significantly enhances the oxygen evolution reaction (OER) efficiencies in comparison to bare NiFe-MOFs, achieving a current density of 20 mA cm−2 at a low overpotential of 248 mV as well as durability for at least 40 h. Meanwhile, the electronics, optics, band gap energy and local strains of CeO2 decorated with 2D NiFe-MOFs are different to the properties of bare CeO2. Our study on the construction of an ultrathin CeO2 surface-coordinated and confined MOF layer may pave a new way for novel 2D MOF composites/heterostructures or multi-functional 2D CeO2 materials to be used in energy conversion or other fields.
Highlights
The energy crisis and environmental pollution are the most crucial challenges facing humanity today
Many research achievements have been achieved in the preparation of 2D metal–organic framework (MOF), developing the ideal technology to simultaneously control the growth of 2D MOFs along the lateral direction only and suppress vertical growth to the nanometer scale still remains challenging.15 2D MOF-based heterostructures can provide the architectural features of nanometer MOFs; heterostructures can achieve the controllable growth of ultrathin MOFs
We demonstrate that the protocol is bene cial for the chemical functionalization of CeO2 with tailored oxygen-containing functional groups and affords well-de ned 2D CeO2@NiFe-MOF heterostructures, in which ultrathin CeO2 nanosheets with the largest speci c surface area provide a substrate for the dispersion of the 2D NiFe-MOF layer and the thickness of the 2D NiFe-MOFs could be controlled down to nanometers
Summary
The energy crisis and environmental pollution are the most crucial challenges facing humanity today. Bene ting from the unique electronic con gurations of cerium, the coordination of CeO2 may optimize the electronic structure and spatial arrangements of materials.[47] In addition, NiFe-MOFs are nonuniformly distributed on the surface of CeO2 nanosheets, which can expose more active sites and enhance catalytic performance.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
