Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Controlled chemical functionalization toward 3D-2D carbon nanohorn-MoS2
  heterostructures with enhanced electrocatalytic activity for protons
  reduction   The realization of novel heterostructures arising from the combination of
nanomaterials is an effective way to modify their physicochemical and
electrocatalytic properties, giving them enhanced characteristics stemming from
their individual constituents. Interfacing carbon nanohorns (CNHs) possessing
high porosity, large specific surface area and good electrical conductivity,
with MoS2 owning multiple electrocatalytic active sites but lacking significant
conductivity, robust interactions and effective structure, can be a strategy to
boost the electrocatalytic reduction of protons to molecular hydrogen. Herein,
we covalently introduce, in a stepwise approach, complementary functional
groups at the conical tips and sidewalls of CNHs, along with the basal plane of
MoS2, en route the construction of 3D-2D CNH-MoS2 heterostructures. The
increased MoS2 loading onto CNHs, improving and facilitating charge
delocalization and transfer in neighboring CNHs, along with the plethora of
active sites, results in excellent electrocatalytic activity for protons
reduction same to that of commercial Pt/C. We have registered minute
overpotential, low Tafel slope and small charge-transfer resistance for
electrocatalyzing the evolution of hydrogen from the newly prepared
heterostructure of 0.029 V, 71 mV/dec and 34.5 {\Omega}, respectively.
Furthermore, the stability of the 3D-2D CNH-MoS2 heterostructure was validated
after performing 10,000 ongoing electrocatalytic cycles.

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The categories of this paper are: nucl-th
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The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
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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: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: astro-ph
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol