Research
article
Sacrificial
MOF-derived
MnNi
hydroxide
for high
energy
storage
supercapacitor
electrodes
via DFT-based
quantum
capacitance
study
Elahe
Torabi
a
, Amir
Kazemi
a
,
b
, Mohsen
Tamtaji
c
, Faranak
Manteghi
a
,
*
,
Sohrab
Rohani
b
, William
A. Goddard
d
a
Research
Laboratory
of Inorganic
Chemistry
and Environment,
Department
of Chemistry,
Iran University
of Science
and Technology,
16846-13114,
Tehran,
Iran
b
Department
of Chemical
and Biochemical
Engineering,
Western
University,
London,
ON, N6A
5B9 Canada
c
Department
of Chemical
and Petroleum
Engineering,
Sharif
University
of Technology,
Tehran,
Iran
d
Materials
and Process
Simulation
Center,
California
Institute
of Technology,
Pasadena,
CA, 91125,
USA
ARTICLE
INFO
Keywords:
MOF-74
Bimetallic
hydroxide
Supercapacitor
DFT calculations
ABSTRACT
Electrochemical
energy
storage
plays
a critical
role in the transition
to clean
energy.
With
the
growing
demand
for efficient
and sustainable
energy
solutions,
supercapacitors
have
gained
significant
attention
due to their
high
specific
capacitance,
rapid
charge/discharge
capabilities,
long
lifespan,
safe operation
across
various
temperatures,
and minimal
maintenance
needs.
This
study
introduces
a novel
approach
for the synthesis
of high-performance
supercapacitor
elec
-
trodes
by using
MnNi-MOF-74
as a precursor.
Bimetallic
Mn(OH)
₂
/Ni(OH)
₂
hydroxides
(MnNi-x,
where
x
=
2, 6, 12) with
tailored
morphologies
were
successfully
fabricated
by treating
MnNi-
MOF-74
anchored
on nickel
foam
with
different
concentrations
of KOH.
Among
the various
synthesized
samples,
MnNi-6
exhibited
the best performance,
with
a remarkable
specific
capac
-
itance
of 4031.51
mF cm
⁻
2
at 2 mA cm
⁻
2
, attributed
to its high
surface
area
of 186 m
2
/g, opti
-
mized
particle
size,
and abundant
micropores.
Furthermore,
MnNi-6
demonstrated
exceptional
thermal
stability,
positioning
it as a promising
candidate
for high-temperature
supercapacitors.
It
also exhibited
excellent
cycling
stability,
retaining
86.34
% of its capacity
after
10,000
cycles
at
10 mA cm
⁻
2
, highlighting
its remarkable
durability.
Density
functional
theory
(DFT)
calculations
were
conducted
to explore
the quantum
capacitance
of the bimetallic
hydroxide.
The DFT results
revealed
electron
density
near
the Fermi
level,
which
directly
contributes
to the high
quantum
capacitance
of Mn(OH)
₂
/Ni(OH)
₂
with
a Mn:Ni
molar
ratio
of 3:1. This
work
underscores
the
potential
of MOF-derived
materials
as a promising
route
for the development
of high-performance
supercapacitor
electrodes,
paving
the way for future
advances
in electrochemical
energy
storage
technologies.
*
Corresponding
author.
E-mail
addresses:
elahetorabi1377@gmail.com
(E. Torabi),
Kazemistudy@gmail.com
(A. Kazemi),
Mtamtaji@connect.ust.hk
(M. Tamtaji),
f_
manteghi@iust.ac.ir
(F. Manteghi),
srohani@uwo.ca
(S. Rohani),
wagoddard3@gmail.com
(W.A.
Goddard).
Contents
lists available
at
ScienceDirect
Heliyon
journal
homepag
e:
www.cell.co
m/heliyon
https://doi.org/10.1016/j.heliyon.2024.e41261
Received
19 September
2024;
Received
in revised
form
19 November
2024;
Accepted
13 December
2024
Heliyon
11
(2025)
e41261
Available
online
18
December
2024
2405-8440/©
2024
Published
by
Elsevier
Ltd.
This
is
an
open
access
article
under
the
CC
BY-NC-ND
license
(
http://creativecommons.org/licenses/by-nc-nd/4.0/
).
1. Introduction
The extensive
reliance
on fossil
fuels
such
as oil, gas, and coal has led to environmental
challenges,
due to the emission
of CO
2
and
the resulting
greenhouse
effect
[
1
,
2
]. Therefore,
the development
of clean
and sustainable
energy
sources
is crucial
to address
environmental
challenges
and meet
the growing
global
energy
demands
while
minimizing
the impact
on the planet.
This
shift
is
essential
for ensuring
a sustainable
future
and reducing
reliance
on traditional,
non-renewable
energy
sources
[
3
,
4
]. As a result,
the
focus
has shifted
toward
advanced
energy
storage
technologies,
which
play
a crucial
role in transitioning
to sustainable
energy
so
-
lutions.
Various
renewable
and sustainable
electrochemical
energy
storage
devices,
including
batteries
and supercapacitors,
are now
available
[
5
,
6
]. Supercapacitors
(SCs)
have
several
advantages
over
traditional
batteries
and capacitors,
including
a longer
lifespan,
high
specific
capacitance,
and high
power
density.
They
offer
exceptional
cycling
stability,
high
power
output,
and operate
safely
with
a lower
risk of failure
[
7
–
9
]. Energy
storage
in supercapacitors
is based
on electrochemical
conversion
reactions,
which
allow
them
to
store
and release
energy
efficiently
[
10
–
12
]. Energy
storage
in supercapacitors
(SCs)
involves
three
main
mechanisms
that work
together
to ensure
efficient
energy
storage
and rapid
discharge.
The first mechanism
is ion adsorption
and release
at the interface
between
the electrode
and the electrolyte.
The second
involves
chemical
reactions
near
the electrode
surface,
where
electron
transfer
plays
a crucial
role.
Lastly,
controlled
electron
movement
through
diffusion
within
the electrode
material
further
contributes
to energy
storage.
These
processes
enable
SCs to deliver
high
power
output
and excellent
cycling
stability
[
13
–
16
]. However,
achieving
high-performance
energy
storage
capacitors
heavily
depends
on the structure
and composition
of the electrode
materials.
Various
materials
have
been
explored
for this purpose,
including
metal
oxides
[
17
,
18
], perovskite
oxides
[
19
,
20
], layer
double
hydroxides
(LDHs)
[
21
,
22
], metal
chalcogenides
[
23
,
24
], MXenes
[
25
,
26
], and metal-organic
frameworks
(MOFs)
[
27
,
28
]. The field
of energy
storage
has seen
a significant
increase
in the exploration
of various
materials,
including
MOFs,
to meet
the rising
demand
for sus
-
tainable
and high-performance
energy
solutions.
These
materials
offer
promising
potential
for improving
energy
storage
systems
by
enhancing
efficiency,
capacity,
and environmental
friendliness
[
29
,
30
]. Among
the vast array
of MOFs
available,
MOF-74
has emerged
as a prominent
candidate
due to its exceptional
structural
stability
and high surface
area [
31
,
32
]. The unique
and adjustable
structures
of MOFs
enable
precise
control
over
the secondary
building
units
(SBUs)
and organic
ligands.
This
capability
allows
researchers
to
optimize
the size,
shape,
and properties
of the pores,
tailoring
them
to meet
the performance
specifications
needed
for specific
ap
-
plications
[
33
,
34
] (see
Scheme
1
).
MOF-74
is one of the unique
metal
organic
frameworks,
which
is synthesized
by using
divalent
metal
salts,
including
transition
metals
such
as Mn
2
+
, Fe
2
+
, Co
2
+
, Ni
2
+
, Cu
2
+
, Zn
2
+
, and the organic
ligand
2,5-dihydroxy
1,4-benzene
dicarboxylate
[
35
,
36
]. In
MOF-74,
the metals
are coordinated
with
five oxygen
atoms
of the H
4
DOT
ligand
and one solvent
molecule
and form
a hexagonal
structure
with
a one-dimensional
channel
with
a honeycomb
topology.
In addition,
MOF-74
has a microporous
structure
with
a pore
size of 12 Å and a specific
surface
area
of 1218
m
2
g