Computational Modeling of Layered Structure of IrO2 and IrOOH
Publicerad
Författare
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The increasing demand for clean energy has intensified research into materials that
can enhance the efficiency of electrochemical processes such as water electrolysis.
Layered transition metals oxides and oxyhydroxides have drawn interest because of
their versatility as an electrocatalyst. Iridium-based catalysts have gained particular
interest for their multivalent state among these electrocatalysts. Here, we examine
the electronic and structural characteristics of layered IrO2 and IrOOH. This thesis
presents a comprehensive computational study of the structural, electronic, and
vibrational properties of IrO2 and IrOOH, using Density Functional Theory (DFT)
with van der Waals (vdW) corrections to investigate and model the structures.
Using functionals such as PBE+rVV10L and SCAN+rVV10, various stacking arrangements
(AA, AB, AA′, and AB′) for IrO2 were investigated, with AA stacking
consistently predicted as the lowest energetically configuration. The minimal energy
differences between AA and AB′ stackings suggest the potential for stacking
faults. Additionally, the impact of structural distortions on the dynamical stability
and electronic properties of IrO2 was explored, revealing that distortions can induce
a transition from metallic to semiconducting behavior. IrOOH is modeled by hydrogenating
the IrO2 structure, and both pristine and distorted configurations were
analyzed. The electronic band structure predicts that IrOOH behaves as a semiconductor,
where the distorted structure reverts to pristine-like. This work deepens
our understanding of the structural and electronic properties that contribute to
modeling the layered structures of IrO2 and IrOOH. Such insights are expected to
be crucial for future theoretical and experimental efforts to optimize the materials
for green energy technologies, including water splitting and other electrochemical
applications.
Beskrivning
Ämne/nyckelord
Layered material, transition metals, oxides, hydroxides, IrO2, IrOOH, density functional theory, Dynamic stability