NiCo layered double hydroxide/hydroxide nanosheet heterostructures for highly efficient electro-oxidation of urea

Urea oxidation is an important reaction for direct urea fuel cells as well as hydrogen production and/or water remediation via electrolysis using urea-rich wastewater. The key to efficient urea oxidation is to explore a well-designed high-performing catalyst. Herein, NiCo layered double hydroxide/hydroxide (NiCo LDH/NiCo(OH)(2)) microspheres composed of ultrasmall nanosheets have been grown on Ni foam by a solution method at room temperature. The NiCo LDH/NiCo(OH)(2) heterostructures have been confirmed by TEM and XRD analysis. The high activity with a small onset potential of 0.29 V vs. Hg/HgO is mainly attributed to the rich NiCo LDH-NiCo(OH)(2) interfaces and the bimetallic nature of the catalysts. The NiCo LDH/NiCo(OH)(2) heterostructures can be promising catalysts for urea oxidation and offer new insights into the design of high-performance nickel-based catalysts. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.