Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Facile synthesis and enhanced visible light photocatalytic activity of N
  and Zr co-doped TiO2 nanostructures from nanotubular titanic acid precursors   Zr/N co-doped TiO2 nanostructures were successfully synthesized using
nanotubular titanic acid (NTA) as precursors by a facile wet chemical route and
subsequent calcination. These Zr/N-doped TiO2 nanostructures made by NTA
precursors show significantly enhanced visible light absorption and much higher
photocatalytic performance than the Zr/N-doped P25 TiO2 nanoparticles. Impacts
of Zr/N co-doping on the morphologies, optical properties, and photocatalytic
activities of the NTA precursor-based TiO2 were thoroughly investigated. The
origin of the enhanced visible light photocatalytic activity is discussed in
detail.

1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio