Dendrimer-functionalized magnetic nanoparticles: A new electrode
material for electrochemical energy storage devices
Sudeshna Chandra
a, c, 1
, Mumukshu D. Patel
a, 1
, Heinrich Lang
b
, Dhirendra Bahadur
a, *
a
Department of Metallurgical Engineering & Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India
b
Inorganic Chemistry, Institute of Chemistry, Technische Universit€ at Chemnitz, D-09107 Chemnitz, Germany
c
Department of Chemical Sciences, School of Science, SVKM's NMIMS University, Vile Parle (West), Mumbai 400056, Maharashtra, India
highlights graphical abstract
Synthesis of redox active NH
2
-
PAMAM dendrimer for stabilizing
and functionalizing Fe
3
O
4
to get
Fe
3
O
4
@D-NH
2
nanoparticles.
Exploring the possibility of using
mesoporous Fe
3
O
4
@D-NH
2
as elec-
trode material for fabrication of en-
ergy storage device.
Fe
3
O
4
@D-NH
2
exhibited high charge
storage and delivery capabilities with
optimum capacitance of 70e120 F/g.
Fe
3
O
4
@D-NH
2
nanoparticles exhibi-
ted enhanced current charging-
discharging with improved retention
time upto 500 cycles.
article info
Article history:
Received 20 December 2014
Accepted 13 January 2015
Available online 16 January 2015
Keywords:
Dendrimer
Magnetic nanoparticles
Supercapacitors
Impedance
abstract
A 10-arm eNH
2
terminated polyamidoamine (PAMAM) dendrimer with a diethylenetriamine core and a
redox centre is synthesized using a new protocol. This dendrimer is further used to produce dendrimer-
functionalized magnetic nanoparticles (Fe
3
O
4
@D-NH
2
), which are potential electrode and supercapacitor
materials for electrochemical supercapacitors. The electron charge transfer mechanism between the core
and the branched surface of the dendrimers is ideal for energy storage. Iron oxide nanoparticles with
high specific surface area and porosity are looked upon as electrochemically active materials. Combining
the advantages from both dendrimers and iron oxide nanoparticles, porous Fe
3
O
4
@D-NH
2
is of consid-
erable interest due to its large surface area, unique porous structure, diversified composition and
excellent electronic conductivity. These extraordinary features enable Fe
3
O
4
@D-NH
2
to offer high specific
capacitance and charge/discharge rate which make them promising candidates as electrode material
in supercapacitors, combining high-energy storage densities with high levels of power delivery. The
electrochemical behavior of the material is studied by cyclic voltammetry, which shows typical rect-
angular IeV behavior of an ideal supercapacitor. With a high surface area, the nanoparticles exhibits high
charge storage and delivery capabilities possessing optimum capacitance value in the range of 70e120 F/
g depending on material loadings in various electrolytes.
© 2015 Published by Elsevier B.V.
* Corresponding author.
E-mail address: dhirenb@iitb.ac.in (D. Bahadur).
1
Both the authors have equal contributions.
Contents lists available at ScienceDirect
Journal of Power Sources
journal homepage: www.elsevier.com/locate/jpowsour
http://dx.doi.org/10.1016/j.jpowsour.2015.01.075
0378-7753/© 2015 Published by Elsevier B.V.
Journal of Power Sources 280 (2015) 217e226