Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theoretical proposal of a revolutionary water-splitting photocatalyst:
  The monolayer of boron phosphide   Recently, hydrogen generation by water-splitting photocatalysts is attracting
attention as a sustainable and clean energy resource. Photocatalytic
hydrogen-generation systems are much simpler, cheaper, and easier to scale up
than the coupled systems of electrolysis and solar cells, wind-power
generation, etc. However, photocatalytic hydrogen generation is currently
inefficient. This paper proposes the monolayer of boron phosphide as a stable
highly-efficient water-splitting photocatalyst by high-precision
density-functional theory calculations using a HSE06 functional with a solvent
effect. The monolayer of boron phosphide has a direct allowed energy gap of
about 1.4 eV, and functions as a one-step excitation photocatalyst. It absorbs
sunlight with wavelengths below about 890 nm (ultraviolet, visible, and
near-infrared light) and produces both hydrogen gas and oxygen gas from water
at a suitable pH condition. By calculating the overpotentials of hydrogen and
oxygen evolution reactions, its photocatalytic effectiveness was confirmed. The
monolayers of boron phosphide will realize green hydrogen revolution.

21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ