TY  - JOUR
AU  - Wei, Xian-Kui
AU  - Xiong, Dehua
AU  - Liu, Lifeng
AU  - Dunin-Borkowski, Rafal E.
TI  - Self-Epitaxial Hetero-Nanolayers and Surface Atom Reconstruction in Electrocatalytic Nickel Phosphides
JO  - ACS applied materials & interfaces
VL  - 12
IS  - 19
SN  - 1944-8252
CY  - Washington, DC
PB  - Soc.
M1  - FZJ-2020-02731
SP  - 21616 - 21622
PY  - 2020
AB  - Surface atomic, compositional, and electronic structures play decisive roles in governing the performance of catalysts during electrochemical reactions. Nevertheless, for efficient and cheap transition-metal phosphides used for water splitting, such atomic-scale structural information is largely missing. Despite much effort being made so far, there is still a long way to go for establishing a precise structure–activity relationship. Here, in combination with electron-beam bombardment and compositional analysis, our atomic-scale transmission electron microscopy study on Ni5P4 nanosheets, with a preferential (001) orientation, directly reveals the coverage of a self-epitaxial Ni2P nanolayer on the phosphide surface. Apart from the presence of nickel vacancies in the Ni5P4 phase, our quantum-mechanical image simulations also suggest the existence of an additional NiPx (0 < x < 0.5) nanolayer, characteristic of complex surface atom reconstruction, on the outermost surface of the phosphides. The surface chemical gradient and the core–shell scenario, probably responsible for the passivated catalytic activity, provide a novel insight to understand the catalytic performance of transition-metal catalysts used for electrochemical energy conversion.
LB  - PUB:(DE-HGF)16
C6  - pmid:32301601
UR  - <Go to ISI:>//WOS:000535246100045
DO  - DOI:10.1021/acsami.0c03154
UR  - https://juser.fz-juelich.de/record/878262
ER  -