Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Impact of Nitrogen Doping on Structural and Electronic Properties of
  Titanium Sesquioxide, Ti 2 O 3 : An ab-initio Study   Titanium-based oxides are abundant, chemically stable, non-toxic, and highly
versatile materials, with applications ranging from photovoltaics to catalysis.
For rutile and anatase phases of Titanium dioxide (TiO2), the bandgap ranges
from 3.0-3.2 eV, which are too large to absorb in the visible range (400 nm -
700 nm), resulting in poor photo-catalytic efficiency. Nitrogen doping into
TiO2 has been able to narrow its bandgap, forming an absorption tail in the
visible-light region. However, TiO2 has limits to which it can be doped,
suggesting investigations of the oxygen-deficient Ti203. Using the
state-of-the-art Density Functional Theory (DFT) as implemented in the Quantum
ESPRESSO package, we report on the structural and electronic properties of
corundum-type Ti2N20 (an example TinN2O2n-3 compound with n=2). The most stable
sample of the oxynitride (Ti2N2O-P1), has a bandgap of 2.2 eV, which is clearly
near the middle of the visible light part of the electromagnetic spectrum, and
has no in-gap states, suggesting that they are more efficient
visible-light-driven materials for photocatalytic applications compared to
TiO2, TiO2: N and Ti2O3.

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The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-th
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The categories of this paper are: math
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The categories of this paper are: acc-phys
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The categories of this paper are: cs
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ph
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The categories of this paper are: mtrl-th