TITLE:
First-Principles Investigation of Energetics and Electronic Structures of Ni and Sc Co-Doped MgH2
AUTHORS:
Gaili Sun, Yuanyuan Li, Xinxin Zhao, Yiming Mi, Lili Wang
KEYWORDS:
First-Principles Calculation, MgH2, Stability, Enthalpy, Dehydrogenation Property, Electronic Structure
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.7 No.1,
January
22,
2016
ABSTRACT: First-principles
calculations were used to study the energetics and electronic structures of Ni
and Sc co-doped MgH2 system. The preferential positions for dopants
were determined by the minimal total electronic energy. The results of
formation enthalpy indicate that Ni and Sc co-doped MgH2 system is
more stable than Ni single-doped system. The hydrogen desorption enthalpies of
these two hydrides are investigated. Ni and Sc co-doping can improve the
dehydrogenation properties of MgH2. The lowest hydrogen desorption
enthalpy of 0.30 eV appears in co-doped system, which is significantly lower
than that of Ni doping. The electronic structure analysis illustrates that the
hybridization of dopants with Mg and H atom together weakens the Mg-H
interaction. And the Mg-H bonds are more susceptible to dissociate by Ni and Sc
co-doping because of the reduced magnitude of Mg-H hybridization peaks. These
behaviors effectively improve the dehydrogenation properties of Ni and Sc
co-doped cases.