Saranya Lakshmi | Pondicherry university (original) (raw)
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Papers by Saranya Lakshmi
RSC Adv., 2014
Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-as... more Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-assisted exfoliation technique.
Materials Research Bulletin, 2016
Abstract Generally, platinum (Pt) is used as a counter electrode (CE) for triiodide (I 3 − ) redu... more Abstract Generally, platinum (Pt) is used as a counter electrode (CE) for triiodide (I 3 − ) reduction in the electrolyte solution of dye-sensitized solar cell (DSSC). Unfortunately, the high cost and scarcity of Pt make the limitation for large scale production of DSSCs. Hence, to replace Pt, we have prepared the titanium carbide (TiC) embedded carbon nanofibers (CNFs) by a facile electrospinning technique and used as a low cost alternative CE for DSSCs. The TiC embedded CNFs are found to have an enhanced electrocatalytic activity towards the I 3 – to iodide (I – ) reduction and lower charge transfer resistance. The photovoltaic performance shows that the DSSC fabricated using TiC (10 wt%) embedded CNFs as CE has very closer photo-conversion efficiency than std. Pt. This is attributed to the synergistic effect of TiC with larger electrocatalytic surface area of CNFs which plays a substantial part in the improvement of photovoltaic performance of DSSC.
Materials Letters, 2012
Abstract The great demand for batteries with high power and energy densities promotes active rese... more Abstract The great demand for batteries with high power and energy densities promotes active research on lithium garnets for advanced safe lithium ion battery technologies. Lithium garnets Li 7 La 3 M 2 O 12 (M = Zr, Hf) in cubic phase exhibits two orders of higher conductivity compared to their tetragonal phase. Earlier efforts to stabilize related Li 7 La 3 Sn 2 O 12 in cubic phase by solid state method was unsuccessful. In this work, an attempt has been made to synthesise Sn-based lithium garnets in cubic phase. The addition of Al 2 O 3 chemically did not help to stabilize Li 7 La 3 Sn 2 O 12 in cubic phase through solid state method. Sn-based lithium garnets Li 7- x La 3 Sn 2- x Nb x O 12 ( x = 0–1) were prepared through solid state reaction method. Li 7- x La 3 Sn 2- x Nb x O 12 with x ≥ 0.25 stabilizes in cubic structure at sintering temperature around 950 °C.
European Polymer Journal, 2015
Conducting polymers (CPs) have been widely investigated and applied in various applications such ... more Conducting polymers (CPs) have been widely investigated and applied in various applications such as sensors, supercapacitors, energy storage devices, dye-sensitized solar cells (DSSCs) and others. They are pseudo-capacitive materials and can undergo fast redox reactions. Counter electrode (CE) is an important component in DSSCs. The counter electrode function as an electron transfer agent as well as the regenerator of redox couple. So far various methods and materials are used to prepare different counter electrodes. This paper reviews the conducting polymers and their composites as counter electrodes which offer a valuable insight to find out the appropriate alternative to costly platinum (Pt) counter electrode for DSSCs. Furthermore, it also outlines the desirable properties for good counter electrode materials and their evaluation methods such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Tafel polarization and chronoamperometry with photovoltaic performance studies for DSSCs.
Generally, platinum (Pt) is used as a counter electrode (CE) for triiodide (I3 ) reduction in th... more Generally, platinum (Pt) is used as a counter electrode (CE) for triiodide (I3
) reduction in the electrolyte
solution of dye-sensitized solar cell (DSSC). Unfortunately, the high cost and scarcity of Pt make the
limitation for large scale production of DSSCs. Hence, to replace Pt, we have prepared the titanium
carbide (TiC) embedded carbon nanofibers (CNFs) by a facile electrospinning technique and used as a low
cost alternative CE for DSSCs. The TiC embedded CNFs are found to have an enhanced electrocatalytic
activity towards the I3
– to iodide (I–) reduction and lower charge transfer resistance. The photovoltaic
performance shows that the DSSC fabricated using TiC (10 wt%) embedded CNFs as CE has very closer
photo-conversion efficiency than std. Pt. This is attributed to the synergistic effect of TiC with larger
electrocatalytic surface area of CNFs which plays a substantial part in the improvement of photovoltaic
performance of DSSC.
The great demand for batteries with high power and energy densities promotes active research on l... more The great demand for batteries with high power and energy densities promotes active research on lithium garnets
for advanced safe lithiumion battery technologies. Lithium garnets Li7La3M2O12 (M=Zr, Hf) in cubic phase
exhibits two orders of higher conductivity compared to their tetragonal phase. Earlier efforts to stabilize related
Li7La3Sn2O12 in cubic phase by solid state method was unsuccessful. In this work, an attempt has been made to
synthesise Sn-based lithium garnets in cubic phase. The addition of Al2O3 chemically did not help to stabilize
Li7La3Sn2O12 in cubic phase through solid state method. Sn-based lithium garnets Li7-xLa3Sn2-xNbxO12 (x=0–
- were prepared through solid state reaction method. Li7-xLa3Sn2-xNbxO12 with x≥0.25 stabilizes in cubic structure
at sintering temperature around 950 °C.
Conducting polymers (CPs) have been widely investigated and applied in various applications such ... more Conducting polymers (CPs) have been widely investigated and applied in various applications
such as sensors, supercapacitors, energy storage devices, dye-sensitized solar cells
(DSSCs) and others. They are pseudo-capacitive materials and can undergo fast redox reactions.
Counter electrode (CE) is an important component in DSSCs. The counter electrode
function as an electron transfer agent as well as the regenerator of redox couple. So far various
methods and materials are used to prepare different counter electrodes. This paper
reviews the conducting polymers and their composites as counter electrodes which offer
a valuable insight to find out the appropriate alternative to costly platinum (Pt) counter
electrode for DSSCs. Furthermore, it also outlines the desirable properties for good counter
electrode materials and their evaluation methods such as cyclic voltammetry (CV), electrochemical
impedance spectroscopy (EIS), Tafel polarization and chronoamperometry with
photovoltaic performance studies for DSSCs.
Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-as... more Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-assisted
exfoliation technique. The as prepared GNs are decorated with platinum (Pt) nanoparticles by a simple
chemical reduction method and used as a low-cost counter electrode (CE) material for dye-sensitized
solar cells (DSSCs). Structure and morphology of the prepared GNs and Pt-decorated GNs (Pt–GNs) are
evaluated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM),
transmission electron microscopy (TEM) and selected area electron diffraction (SAED) studies. The
electrochemical behavior of GNs and Pt–GNs are compared with std. Pt using cyclic voltammetry (CV)
and electrochemical impedance spectroscopy (EIS) studies. These studies indicate that the Pt–GNsbased
counter electrode offered superior electrocatalytic activity towards the I/I3
redox mediator with
enhanced charge transfer rate and exchange current density at the electrode/electrolyte interface over
std. Pt and GNs-based counter electrodes. DSSCs are fabricated with std. Pt, GNs and Pt–GNs to
determine the photovoltaic performance under 1 Sun illumination (100 mW cm2, AM 1.5). It is found
that the cell fabricated with 1 wt% Pt-decorated GNs as counter electrode showed an 11% improvement
in photovoltaic cell efficiency compared with the cell assembled with std. platinum and other reported
graphene–Pt-based composites as counter electrodes.
RSC Adv., 2014
Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-as... more Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-assisted exfoliation technique.
Materials Research Bulletin, 2016
Abstract Generally, platinum (Pt) is used as a counter electrode (CE) for triiodide (I 3 − ) redu... more Abstract Generally, platinum (Pt) is used as a counter electrode (CE) for triiodide (I 3 − ) reduction in the electrolyte solution of dye-sensitized solar cell (DSSC). Unfortunately, the high cost and scarcity of Pt make the limitation for large scale production of DSSCs. Hence, to replace Pt, we have prepared the titanium carbide (TiC) embedded carbon nanofibers (CNFs) by a facile electrospinning technique and used as a low cost alternative CE for DSSCs. The TiC embedded CNFs are found to have an enhanced electrocatalytic activity towards the I 3 – to iodide (I – ) reduction and lower charge transfer resistance. The photovoltaic performance shows that the DSSC fabricated using TiC (10 wt%) embedded CNFs as CE has very closer photo-conversion efficiency than std. Pt. This is attributed to the synergistic effect of TiC with larger electrocatalytic surface area of CNFs which plays a substantial part in the improvement of photovoltaic performance of DSSC.
Materials Letters, 2012
Abstract The great demand for batteries with high power and energy densities promotes active rese... more Abstract The great demand for batteries with high power and energy densities promotes active research on lithium garnets for advanced safe lithium ion battery technologies. Lithium garnets Li 7 La 3 M 2 O 12 (M = Zr, Hf) in cubic phase exhibits two orders of higher conductivity compared to their tetragonal phase. Earlier efforts to stabilize related Li 7 La 3 Sn 2 O 12 in cubic phase by solid state method was unsuccessful. In this work, an attempt has been made to synthesise Sn-based lithium garnets in cubic phase. The addition of Al 2 O 3 chemically did not help to stabilize Li 7 La 3 Sn 2 O 12 in cubic phase through solid state method. Sn-based lithium garnets Li 7- x La 3 Sn 2- x Nb x O 12 ( x = 0–1) were prepared through solid state reaction method. Li 7- x La 3 Sn 2- x Nb x O 12 with x ≥ 0.25 stabilizes in cubic structure at sintering temperature around 950 °C.
European Polymer Journal, 2015
Conducting polymers (CPs) have been widely investigated and applied in various applications such ... more Conducting polymers (CPs) have been widely investigated and applied in various applications such as sensors, supercapacitors, energy storage devices, dye-sensitized solar cells (DSSCs) and others. They are pseudo-capacitive materials and can undergo fast redox reactions. Counter electrode (CE) is an important component in DSSCs. The counter electrode function as an electron transfer agent as well as the regenerator of redox couple. So far various methods and materials are used to prepare different counter electrodes. This paper reviews the conducting polymers and their composites as counter electrodes which offer a valuable insight to find out the appropriate alternative to costly platinum (Pt) counter electrode for DSSCs. Furthermore, it also outlines the desirable properties for good counter electrode materials and their evaluation methods such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Tafel polarization and chronoamperometry with photovoltaic performance studies for DSSCs.
Generally, platinum (Pt) is used as a counter electrode (CE) for triiodide (I3 ) reduction in th... more Generally, platinum (Pt) is used as a counter electrode (CE) for triiodide (I3
) reduction in the electrolyte
solution of dye-sensitized solar cell (DSSC). Unfortunately, the high cost and scarcity of Pt make the
limitation for large scale production of DSSCs. Hence, to replace Pt, we have prepared the titanium
carbide (TiC) embedded carbon nanofibers (CNFs) by a facile electrospinning technique and used as a low
cost alternative CE for DSSCs. The TiC embedded CNFs are found to have an enhanced electrocatalytic
activity towards the I3
– to iodide (I–) reduction and lower charge transfer resistance. The photovoltaic
performance shows that the DSSC fabricated using TiC (10 wt%) embedded CNFs as CE has very closer
photo-conversion efficiency than std. Pt. This is attributed to the synergistic effect of TiC with larger
electrocatalytic surface area of CNFs which plays a substantial part in the improvement of photovoltaic
performance of DSSC.
The great demand for batteries with high power and energy densities promotes active research on l... more The great demand for batteries with high power and energy densities promotes active research on lithium garnets
for advanced safe lithiumion battery technologies. Lithium garnets Li7La3M2O12 (M=Zr, Hf) in cubic phase
exhibits two orders of higher conductivity compared to their tetragonal phase. Earlier efforts to stabilize related
Li7La3Sn2O12 in cubic phase by solid state method was unsuccessful. In this work, an attempt has been made to
synthesise Sn-based lithium garnets in cubic phase. The addition of Al2O3 chemically did not help to stabilize
Li7La3Sn2O12 in cubic phase through solid state method. Sn-based lithium garnets Li7-xLa3Sn2-xNbxO12 (x=0–
- were prepared through solid state reaction method. Li7-xLa3Sn2-xNbxO12 with x≥0.25 stabilizes in cubic structure
at sintering temperature around 950 °C.
Conducting polymers (CPs) have been widely investigated and applied in various applications such ... more Conducting polymers (CPs) have been widely investigated and applied in various applications
such as sensors, supercapacitors, energy storage devices, dye-sensitized solar cells
(DSSCs) and others. They are pseudo-capacitive materials and can undergo fast redox reactions.
Counter electrode (CE) is an important component in DSSCs. The counter electrode
function as an electron transfer agent as well as the regenerator of redox couple. So far various
methods and materials are used to prepare different counter electrodes. This paper
reviews the conducting polymers and their composites as counter electrodes which offer
a valuable insight to find out the appropriate alternative to costly platinum (Pt) counter
electrode for DSSCs. Furthermore, it also outlines the desirable properties for good counter
electrode materials and their evaluation methods such as cyclic voltammetry (CV), electrochemical
impedance spectroscopy (EIS), Tafel polarization and chronoamperometry with
photovoltaic performance studies for DSSCs.
Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-as... more Graphene nanosheets (GNs) are prepared from natural graphite by a simple ecofriendly microwave-assisted
exfoliation technique. The as prepared GNs are decorated with platinum (Pt) nanoparticles by a simple
chemical reduction method and used as a low-cost counter electrode (CE) material for dye-sensitized
solar cells (DSSCs). Structure and morphology of the prepared GNs and Pt-decorated GNs (Pt–GNs) are
evaluated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM),
transmission electron microscopy (TEM) and selected area electron diffraction (SAED) studies. The
electrochemical behavior of GNs and Pt–GNs are compared with std. Pt using cyclic voltammetry (CV)
and electrochemical impedance spectroscopy (EIS) studies. These studies indicate that the Pt–GNsbased
counter electrode offered superior electrocatalytic activity towards the I/I3
redox mediator with
enhanced charge transfer rate and exchange current density at the electrode/electrolyte interface over
std. Pt and GNs-based counter electrodes. DSSCs are fabricated with std. Pt, GNs and Pt–GNs to
determine the photovoltaic performance under 1 Sun illumination (100 mW cm2, AM 1.5). It is found
that the cell fabricated with 1 wt% Pt-decorated GNs as counter electrode showed an 11% improvement
in photovoltaic cell efficiency compared with the cell assembled with std. platinum and other reported
graphene–Pt-based composites as counter electrodes.