Page 1 of 6
Modular Assembly of Cu- and Ni-based Micro- and
Nanostructures for Electrochemical Sensing and
Energy Applications
Thesis Submitted to AcSIR for the Award of the Degree of
DOCTOR OF PHILOSOPHY
In
CHEMICAL SCIENCES
By
M. KALEESH KUMAR
Registration Number: 10CC14A05005
Under the Guidance of
Dr. Shailendra Kumar Jha
CSIR - Central Electrochemical Research Institute, Karaikudi-630003, Tamil
Nadu, India
August-2019
Page 2 of 6
Chapter VIII Summary
M Kaleesh Kumar 178
Chapter VIII
Summary and future perspectives
A series of Cu- and Ni-based micro- and nanostructured materials have been prepared via in-situ
electrosynthesized protocol and investigated as catalysts for electrochemical sensing and energy
applications. The electrochemical sensing exeriments have been performed for the selective and
sensitive determination of dopamine, glucose and p-nitrophenol as well as the practical feasibility of
the as-prepared platforms is also shown in real-time samples and environment. On the other side,
some of the as-prepared electrocatalysts have been tested for the electrooxidation of methanol and
formic acid. Finally, a brief conclusion of each chapter is as follows:
Chapter II: Preparation of electro-reduced graphene oxide supported walnut shape nickel
nanostructures, and their application to selective detection of dopamine
The electroreduced graphene oxide supported walnut shape nickel nanocomposites (er-GO-Ni) have
been synthesized by an optimized electrodeposition route. Their applications for the selective
detection of dopamine unravel the facts related to the selectivity in the presence of interfering
species, especially for ascorbic acid (AA) and uric acid (UA). It has been attributed to (i) Nafion (1.0
%) film coating, (ii) repulsive electrostatic interaction with similar negative charge on residual
oxygen functionality of electroreduced graphene oxide (er-GO) and (iii) oxide or hydroxide Ni
species during deposition of sample. The fabricated electrochemical sensor has shown a detection
limit of 10 ± 0.03 nM for dopamine in the presence of interfering species and its applicability can be
explored for the healthcare management.
Page 3 of 6
Chapter VIII Summary
M Kaleesh Kumar 179
Chapter III: Facile in-situ electrosynthesis and high electrocatalytic performance of interconnected
layered double hydroxides/graphene hybrids for dopamine oxidation: a comparative study
A facile in-situ electrodeposition approach has been used to prepare a rational design of M-Al (M:Ni,
Co) layered double hydroxide (LDH)/reduced graphene oxide (G) hybrids and its superior
electrocatalytic activity has been tested for the electrooxidation of dopamine. The regular and
specific worm like interconnected nanochain architecture of NiAl-LDH/G hybrid sensor is
responsible for its improved conductivity, electrocatalytic activity and performance than the CoAl- LDH/G hybrid modified electrode for oxidation of dopamine. The proposed sensor has detected upto
9.8 nM of dopamine and shown the selectivity towards various foreign species, also furnished good
recovery for both the real world samples of human serum and dopamine drug samples.
Chapter IV: Elucidation of confined copper nanospheres within self-assembled curcumin-cysteine
and their electrocatalytic application
The novel combined self-assembly/electrodeposition approach has been explored for the construction
of surface-confined modular Cu metal-ion nanosphere deposited on curcumin-cysteine complex
conjugate monolayer modified gold electrode and tested for p-nitrophenol determination. The
protected copper nanospheres have been formed due its better complextaion with β-diketone of
curcumin in curcumin-cysteine complex conjugate. The optimized electrochemical platform has
shown two linear ranges from 0.97 to 1.76 mM and 0.1 μM to 0.90mM, low detection limits of 69
μM and 57 nM, and high sensitivity of 70.45 μA μM−1
cm−2
and 153.08 μA μM−1
cm−2
, respectively.
The practical feasibility of the electrochemical platform as proposed sensor has been also tested for a
real world samples (i.e., Lake water) and the recoveries of p-nitrophenol were found in the range of
93.2 % to 105.9 %. This combined self-assembly/electrodeposition approach will provide an