Author(s): Wang, C (Wang, Chao); Lu, HL (Lu, Haoliang); Mao, ZY (Mao, Zeyang); Yan, CL (Yan, Chenglin); Shen, GZ (Shen, Guozhen); Wang, XF (Wang, Xianfu)
Source: ADVANCED FUNCTIONAL MATERIALS Article Number: 2000556 DOI: 10.1002/adfm.202000556 Early Access Date: FEB 2020
Abstract: Hydrogen production via water electrocatalysis is limited by the sluggish anodic oxygen evolution reaction (OER) that requires a high overpotential. In response, a urea-assisted energy-saving alkaline hydrogen-production system has been investigated by replacing OER with a more oxidizable urea oxidation reaction (UOR). A bimetal heterostructure CoMn/CoMn2O4 as a bifunctional catalyst is constructed in an alkaline system for both urea oxidation and hydrogen evolution reaction (HER). Based on the Schottky heterojunction structure, CoMn/CoMn2O4 induces self-driven charge transfer at the interface, which facilitates the absorption of reactant molecules and the fracture of chemical bonds, therefore triggering the decomposition of water and urea. As a result, the heterostructured electrode exhibits ultralow potentials of -0.069 and 1.32 V (vs reversible hydrogen electrode) to reach 10 mA cm(-2) for HER and UOR, respectively, in alkaline solution, and the full urea electrolysis driven by CoMn/CoMn2O4 delivers 10 mA cm(-2) at a relatively low potential of 1.51 V and performs stably for more than 15 h. This represents a novel strategy of Mott-Schottky hybrids in electrocatalysts and should inspire the development of sustainable energy conversion by combining hydrogen production and sewage treatment.
Accession Number: WOS:000516610600001
ISSN: 1616-301X
eISSN: 1616-3028
Full Text: https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.202000556