Engineering morphology and electron redistribution of a Ni/WO₃ Mott-Schottky bifunctional electrocatalyst for efficient alkaline urea splitting
File(s)Supporting Information.docx (2.62 MB) Manuscript-ACS AMI.docx (7.33 MB)
Supporting information
Accepted version
Author(s)
Zhang, Kai
Guo, Fengchen
Graham, Nigel
Yu, Wenzheng
Type
Journal Article
Abstract
Construction of the desired morphology and nanointerface to expose the active sites and modulate the electronic structure offers an effective approach to boosting urea splitting for energy-saving hydrogen generation. Herein, we fabricate a Ni/WO3 Mott-Schottky heterojunction electrocatalyst with a hedgehog-like structure supported on Ni foam toward alkaline urea splitting. Different Ni/WO3 morphologies, such as microspheres, hedgehog-like structures, octahedrons, and cubes, were obtained when various ratios of Ni/W feeds were used. The Mott-Schottky nanointerfaces between Ni and WO3 domains are visually confirmed by high-resolution transmission electron microscopy images, which also accelerated the charge transfer rate. Benefiting from the high electrochemically active surface area and enhanced charge transferability, the optimal Ni/WO3 electrode exhibits outstanding catalytic activity toward hydrogen generation with a low overpotential of 163 mV at 100 mA cm-2 in alkaline solution and reduced cell voltage of 1.67 V when coupled with urea oxidation reaction. Theoretical calculations reveal that the Ni sites in Ni/WO3 optimize the H adsorption energy (ΔGH*) with the |ΔGH*| value of 0.097 eV, much lower than that of Ni (0.35 eV) and WO3 (0.235 eV). This work demonstrates important guidance in designing an efficient electrocatalyst for urea splitting.
Date Issued
2023-11-01
Date Acceptance
2023-10-05
Citation
ACS Applied Materials and Interfaces, 2023, 15 (43), pp.50116-50125
ISSN
1944-8244
Publisher
American Chemical Society
Start Page
50116
End Page
50125
Journal / Book Title
ACS Applied Materials and Interfaces
Volume
15
Issue
43
Copyright Statement
Copyright © 2023 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Appl. Mater. Interfaces 2023, after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acsami.3c07246
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/37856676
Subjects
hydrogen evolution reaction
metal/metal oxides
morphology transition
Mott−Schottky heterojunction
urea oxidation reaction
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2023-10-19