Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effect of Dissolved Oxygen Content on Photocatalytic Performance of
  Graphene Oxide   Graphene, a two-dimensional (2D) promising emergent photocatalyst consisting
of earth-abundant elements. This study evaluated the potential of graphene
oxide (GO) towards photocatalytic degradation of a novel organic dye, Methylene
Blue (MB). In this work, photocatalytic activity of graphene oxide (GO),
graphene oxide (GO) along with hydrogen peroxide (H2O2) were tested by
photodegrading Methylene Blue (MB) in aqueous solution. The resulted GO
nanoparticles were characterized by X-ray powder diffraction, Scanning Electron
Microscopy, Energy Dispersive Spectroscopy and Fourier Transform Infrared Ray
Spectroscopy. The XRD data confirms the sharp peak centered at 2Theta=10.44
degree corresponding to (002) reflection of GO. Based on our results, it was
found that the resulted GO nanoparticles along with H2O2 achieved ~92%
photodecolorization of MB compared to ~63% for H2O2 under natural sunlight
irradiation at pH~7 in 60 min. The influences of oxygen and hydrogen peroxide
(H2O2) on the degradation of MB during sunlight/GO process were investigated.
Experimental results indicated that oxygen was a determining parameter for
promoting the photocatalytic degradation. The rate constant of degradation (k1)
increased from 0.019 to 0.042 per minute for dissolved oxygen content (DOC) 3.5
mg/L when direct photocatalysis (MB/GO) and H2O2-assisted photocatalysis
(MB/H2O2/GO) were used. Owing to the fact that H2O2 acted as an electron and
hydroxyl radicals scavenger, the addition of H2O2 should in a proper dosage to
enhance the degradation of MB. Moreover, as the initial concentration of
dissolved oxygen (DO) was increased from 2.8 to 3.9 mg/L, the rate constant of
degradation (k1) increased from 0.035 to 0.062 per minute. The mechanism of
photodegradation and kinetics were also studied for both direct photocatalysis
and H2O2-assisted photocatalysis.

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The categories of this paper are: eess
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The categories of this paper are: dg-ga
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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: bayes-an
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The categories of this paper are: math