Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Accurate Determination of the Charge Transfer Efficiency of Photoanodes
  for Solar Water Splitting
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg