Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electrochemical reduction of thin graphene-oxide films in aqueous
  solutions: restoration of conductivity   Graphene oxide finds applications in different fields of science, including
energy conversion. Electrochemical reduction of graphene oxide (GO)
significantly improves its conductivity. However, the kinetics of this process
depends on the solvent, supporting electrolyte, pH, and numerous other factors.
Most studies report the macroscopic views and ex-situ properties of reduced GO.
To expand the knowledge about GO reduction, in this study, we used cyclic
voltammetry (CV), simultaneous 2 points and 4 points resistance measurement
(s24), conductive atomic force microscopy (AFM), and theoretical calculations.
Using CV, we demonstrated that the choice of supporting electrolyte (KCl or
LiCl) influences the potential range in which electrochemical GO reduction
occurs. The activation energy of this process was estimated to be below 30 kJ
mol-1 in both electrolytes, being significantly lower than that required for
thermal reduction of GO. Simultaneous in situ s24 resistance measurements
suggest that GO films reach a highly conductive state at deep negative
potentials, with an abrupt, irreversible switch from non-conductive to the
conductive state. However, conductive AFM presents a more exact picture of this
process: the reduction of GO films starts locally while the formed conductive
islands grow during the reduction. This mechanism was confirmed by theoretical
calculations indicating that the reduction starts on isolated oxygen-functional
groups over the GO basal plane, while clustered OH groups are more difficult to
reduce. The presented results can help in tailoring reduced GO for a particular
electrochemical application by precisely controlling the reduction degree and
percentage of the conductive area of the reduced GO films.

8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga