Shabana Shaikh | The National University of Malaysia (original) (raw)

Papers by Shabana Shaikh

Chemical Papers

This study primarily focused on the investigation, synthesis and analysis of lanthanum and tin py... more This study primarily focused on the investigation, synthesis and analysis of lanthanum and tin pyrochlores electrolytes for solid oxide fuel cell (SOFC) applications. Ceramic samples with diverse compositions of La 2−x Sr x Sn 2 O 7−δ (x = 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3) were synthesized by using solid-state reaction (SSR) methods. The prepared La 2−x Sr x Sn 2 O 7−δ samples were characterized by using X-ray diffraction, scanning electron microscopy and electrochemical impedance spectroscopy measurements. The results were further interpreted regarding the formation of high oxygen vacancy and structural disorder in the La 2−x Sr x Sn 2 O 7−δ matrix. The doping of lanthanum (La 3+) by strontium (Sr 2+) had a beneficial and remarkable effect on the structural and electrical properties: the increase in dopant (Sr) concentration decreased the lattice parameters of the crystalline phase and enhanced the creation of oxygen vacancies, which consequently increased the ionic conductivity and decreased the activation energy. Thus, it could be understood that the studied new La 2−x Sr x Sn 2 O 7−δ electrolyte would be one of the potential candidates for intermediate temperature SOFC applications.

This study primarily focused on the investigation, synthesis and analysis of lanthanum and tin py... more This study primarily focused on the investigation, synthesis and analysis of lanthanum and tin pyrochlores electrolytes for solid oxide fuel cell (SOFC) applications. Ceramic samples with diverse compositions of La 2−x Sr x Sn 2 O 7−δ (x = 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3) were synthesized by using solid-state reaction (SSR) methods. The prepared La 2−x Sr x Sn 2 O 7−δ samples were characterized by using X-ray diffraction, scanning electron microscopy and electrochemical impedance spectroscopy measurements. The results were further interpreted regarding the formation of high oxygen vacancy and structural disorder in the La 2−x Sr x Sn 2 O 7−δ matrix. The doping of lanthanum (La 3+) by strontium (Sr 2+) had a beneficial and remarkable effect on the structural and electrical properties: the increase in dopant (Sr) concentration decreased the lattice parameters of the crystalline phase and enhanced the creation of oxygen vacancies, which consequently increased the ionic conductivity and decreased the activation energy. Thus, it could be understood that the studied new La 2−x Sr x Sn 2 O 7−δ electrolyte would be one of the potential candidates for intermediate temperature SOFC applications.

Innovations in Microbiology and Biotechnology Vol. 4, 2022

Ba 0.3 Sr 0.7 Co 0.6 Fe 0.4 O 3-δ (BSCF3764) was synthesized via three different methods; solid s... more Ba 0.3 Sr 0.7 Co 0.6 Fe 0.4 O 3-δ (BSCF3764) was synthesized via three different methods; solid state reaction(SSR), glycine nitrate process(GNP), and EDTA-citric acid complexing sol-gel method (SG). Effect of preparation techniques on XRD, microstructure, 4-probe DC conductivity and transport properties using EIS were studied. Both, phase formation temperature and time of BSCF3764 synthesized by SG was found to be low as compared to other two methods. Grain size of around 0.2-0.3 µm in case of SSR and grown grains with size of approximately 0.1-0.2 µm along with pinholes. Composition synthesized by SG showed highest electrical conductivity at around 700 °C. The performance of BSCF3764 cathode on GDC (8020) electrolyte was dependent on the synthesis technique. The ASR values of BSCF3764 prepared by SSR, GNP and Sol-gel were found to be 1.567, 0.931 and 0.548 cm 2 at 700 °C. The cathode polarization resistance and activation energy was found to be minimum in BSCF3764 prepared by SG....

The samples belonging to Cu x Ce 1-x O 2-δ (x = 0.05, 0.1, 0.3, 0.4.0.5 and 0.6) series prepared ... more The samples belonging to Cu x Ce 1-x O 2-δ (x = 0.05, 0.1, 0.3, 0.4.0.5 and 0.6) series prepared by glycine-nitrate process (GNP) using copper nitrate, cerium nitrate and glycine as a fuel. The XRD confirms the formation of Cu x Ce 1-x O 2-δ. The solid solubility limit for Cu x Ce 1-x O 2-δ is up to x = 0.3. The crystallite size of anode materials decreases with the increasing content of Cu. The addition of Cu increases the porosity. The highest conductivity 3.4 × 10-2 Scm-1 is achieved for x = 0.6 and that of x = 0.5 is 2.5 × 10-2 Scm-1 at 660 ºC before reduction. It is found that from mechanical strength point of view Cu x Ce 1-x O 2-δ anode material for x = 0.5 is suitable than other compositions. The electrochemical performance and anode /electrolyte/anode interface of Cu x Ce 1-x O 2-δ anode is studied after reduction in 10%H 2 +90%N 2 and in humidified 10%H 2 +90%N 2 using impedance spectroscopy. The conductivity is maximum for the Cell-800 at Cell-700 ºC having lowest ASR 155...

International Journal of Hydrogen Energy, 2012

Solid oxide fuel cell Ba 0.5 Sr 0.5 Co 0.6 Fe 0.4 O 3Àd (BSCF5564) Scanning electron microscopy 4... more Solid oxide fuel cell Ba 0.5 Sr 0.5 Co 0.6 Fe 0.4 O 3Àd (BSCF5564) Scanning electron microscopy 4-Probe D.C. conductivity a b s t r a c t Ba 0.5 Sr 0.5 Co 0.6 Fe 0.4 O 3Àd (BSCF5564) was synthesized by nitric acid aided EDTAecitric acid complexing sol-gel method (NECC). Both, the phase formation temperature and time of BSCF5564 synthesized NECC were found to be low i.e. single perovskite phase formation temperature is 200 C less as compared to the conventional method of synthesis. The orthorhombic perovskite structure has been formed after calcination at 800 C for 5 h. Scanning electron microscopy reveals the formation of porous material constituting nanosized and irregularly shaped rod-like structure with particle size approximately ranges from 90 to 160 nm. The total weight loss of the BSCF5564 sample comes out to be 6.6%, indicating that quadrivalence state Co 4þ and Fe 4þ in the sample have been completely reduced to the trivalent state Co 3þ and Fe 3þ due to thermal analysis. The value of E a for BSCF5564 prepared by NECC was 0.2288 eV. The electrical conductivity of BSCF5564 synthesized by NECC is observed to be steady at high temperature (above 700 C).

RSC Advances

The gadolinium-doped ceria powder was synthesized using a microwave-synthesized glycine nitrate ... more The gadolinium-doped ceria powder was synthesized using a microwave-synthesized glycine nitrate process (MS-GNP).

ABSTRACT Fuel cells are electrochemical devices that convert chemical energy directly into electr... more ABSTRACT Fuel cells are electrochemical devices that convert chemical energy directly into electrical energy. All types are based on the same principles and have four basic components: electrolyte, anode, cathode, and interconnect. The different fuel cell types are categorized according to their electrolyte since it determines key features such as operating temperature, power-up time, type of fuel, migrating ions, and shock resistance. Fuel cells are generally utilized for secondary power generation, since in cases where they are not using fossil fuels – a possibility only for high temperature fuel cells – pure hydrogen has to be generated by using primary energy sources.Working fuel cell systems have already been developed by many companies in the automobile, electronics, and power generation industries. These systems have to be improved before they can compete on the market with existing technologies, by extending their lifetime and significantly reducing their cost. Two high temperature (solid oxide and molten carbonate) and two low temperature (polymer electrolyte and direct methanol) fuel cells are discussed in more detail, with a focus on the materials and the electrochemical reaction.

Advanced Ceramics and Applications

International Journal of Hydrogen Energy

Abstract The nanoparticles of Mn1.5[Cr(CN)6]∙mH2O@Ni1.5[Cr(CN)6]∙nH2O core-shell prussian blue an... more Abstract The nanoparticles of Mn1.5[Cr(CN)6]∙mH2O@Ni1.5[Cr(CN)6]∙nH2O core-shell prussian blue analogues (PBA) embedded with carbon additives (PBA-C) were synthesized and characterized as electrode material for solid state battery application. The impedance spectroscopy and cyclic voltametry were used to study the electrochemical properties by adding functionalized carbon in 1:1 proportion to improve the electrical performance. The value of room temperature electrical conductivity of core-shell PBA and core-shell nanoparticles mixed with vulcan carbon (PBA-C) are found to be 1.574 × 10−3 and 1.92 × 10−3 Scm−1, respectively. Using Li7La3Zr2O12 (LZZO) electrolyte, single cell was fabricated with PBA-C material, and studied its charging-discharging cycles, which exhibits higher current density with stable performance for 400 cycles for time slots of 400 min. The study reveals that the PBA core-shell nanoparticles mixed with carbon (PBA-C) may be a potential candidate as an electrode material in the form of a single cell using LZZO electrolyte.

Journal of Energy Storage

Abstract Energy demand is increasing in the present world where it is essential to explore altern... more Abstract Energy demand is increasing in the present world where it is essential to explore alternative energy resource that is clean, renewable and sustainable. Graphene is now receiving the great attention as it possesses excellent properties such as high charge mobility up to 230,000 cm2/Vs, 3000 W/m.K thermal conductivity, 2.3% absorption of visible light, strong mechanical strength of 130 GPa and high specific surface area of 2600 m2/g. These properties can be altered depending on synthesis techniques to obtain graphene such as; mechanical exfoliation, reduction of graphene oxide, chemical vapour deposition (CVD) and epitaxial growth of graphene. Furthermore, different characteristics of graphene can be employed for different applications in energy conversion and storage, for example, fuel cell and lithium ion battery. Hence, many studies were investigated to examine graphene and its applications. The objectives of this review is to understand and cover graphene background including properties and synthesis, which will help in understanding better the concept of graphene in its application such as in fuel cell and lithium ion batteries. In addition, it is showing the most key challenges and future consideration when nanostructured graphene is utilized.

Solid oxide fuel cell (SOFC) works by converting chemical energy into electrical energy due to re... more Solid oxide fuel cell (SOFC) works by converting chemical energy into electrical energy due to reforming, and it is one of the promising alternative source of energy for the future. In the present work, emphasis was given on increasing the electronic conductivity of anode material for SOFC. The Cu0.5Ce0.5O2-δ was prepared by mechanochemical (ball milling) route, with and without pore former. The effect of pore former on the electrical and structural characterization was studied in detail, and found that the Cu0.5Ce0.5O2-δ ceramic anode prepared by using pore former is more effective from structural and electrical points of view. The crystallite size is 58 nanoscales and DC conductivity after reduction is 9.50 ×10-1 Scm-2. Thus, the Cu0.5Ce0.5O2-δ prepared by ball milling using pore former technique could be an emerging potential anode material for SOFC.

Journal of Physics and Chemistry of Solids, 2016

Royal Society of Chemistry, 2020

The gadolinium-doped ceria Gd 0.1 Ce 0.9 O 1.95 (10GDC) powder was synthesized using a microwave-... more The gadolinium-doped ceria Gd 0.1 Ce 0.9 O 1.95 (10GDC) powder was synthesized using a microwave-synthesized glycine nitrate process (MS-GNP). The powder was subsequently pressed into circular pellets and sintered at various temperatures viz. 800, 900, 1000 and 1200 C, in a microwave, high temperature furnace for 4 h so as to investigate the effect of the sintering temperature and sintering environment on the structural, morphological, thermal and electrical properties. The crystallite size and particle size as observed from X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) are found to be in the range of 15-28 nm and 12-20 nm, respectively. The electrochemical impedance spectroscopy (EIS) analysis was carried out to study the electrochemical properties during the cooling cycle from 400 C to 800 C. The highest value of ionic conductivity (3.55 Â 10 À1 S cm À1) is observed at an operating temperature of 800 C and O 2 gas partial pressure of 1 atm. Further, it is observed that the sintering temperature has a significant effect on the surface morphology and crystallite size, thereby improving the electrical performance of the samples. Though 20GDC was used as an electrolyte in the authors' previous study, the novelty of the present work is the synthesis of 10GDC using a microwave-assisted glycine nitrate process and the size (thickness) of the prepared electrolyte for use in a Solid Oxide Fuel Cell (SOFC), which plays a major role in enhancing the structural, morphological and electrochemical properties with respect to different sintering temperatures as compared to the reported data. Hence, the prepared 10GDC electrolyte may be treated as one of the promising candidates as an electrolyte for SOFC for intermediate as well as high temperature applications.

In this study, (Bi 2 O 3 ) 1-x-y (Tb 4 O 7 ) x (Gd 2 O 3 ) y (xTbyGdSBi) ternary solid solutions ... more In this study, (Bi 2 O 3 ) 1-x-y (Tb 4 O 7 ) x (Gd 2 O 3 ) y (xTbyGdSBi) ternary solid solutions were synthesized via the solidstate synthesis technique. The phase structures of electrolytes were defined by X-ray powder diffraction (XRD) and differential thermal analysis/thermal gravimetric techniques (DTA/TG). The total electrical conductivity (σ T ) was measured with respect to the test temperature and doping concentration by using four-point probe technique (4PPT). Measurement results showed that δ-phase was obtained in test specimens and the conductivity of the electrolytes increased with increasing test temperature and decreasing amount of Gd 2 O 3. The 5Tb5GdSBi ternary system had the highest conductivity value of 3.88 × 10 −1 S cm −1 at 850°C. Compared to the literature, the results from this study are reasonably promising.

Renewable and Sustainable Energy Reviews, 2015

Solid-oxidefuelcells(SOFCs)arethemostwidelyusedfuelcellsbecausetheyexhibit flexibility,power gene... more Solid-oxidefuelcells(SOFCs)arethemostwidelyusedfuelcellsbecausetheyexhibit flexibility,power generationefficiency,andlowpollutionformation.ResearchonSOFCanodesisamajorandchallenging task inthe field ofSOFCs.ThisreviewhighlightstheanodematerialsthatmaybeusedforSOFC applications. Theuseofcermet-basedoxidematerialsasanodesforSOFCsisalsodiscussedindetail.A literaturesurveyconductedoverthelast10yearsshowsthatincreasedpowergenerationefficiency may be attributedtoanodematerialsusedinsuchcells.Oxide-basedanodematerialswithperovskiteand severaloxideswithcubic fluorite structuresarefurtherdescribed.Basedonthereviewconducted,we find thatcubic fluorite-structuredcompoundsarethemostpromisinganodematerialsreportedthusfar. Analysesofthestructureandelectricalperformanceofanodematerialsshowaswellthatcopper– gadolinium-doped ceriumoxide(Cu–GDC) cubic fluorite-structuredanodesexhibithigherelectronic conductivity potentialthanyttria-stabilizedzirconia-basedanodematerials. & 2015ElsevierLtd.Allrightsreserved.

International Journal of Hydrogen Energy, 2012

ABSTRACT The present work is focused on the comparative analysis of electrochemical and structura... more ABSTRACT The present work is focused on the comparative analysis of electrochemical and structural properties of anode materials for solid oxide fuel cells (SOFCs) and the influence of factors affected on electrode performance. The Cu0.5Ce0.5O2−δ was prepared by Citrate–Nitrate route (CNP) and its formation is confirmed by XRD. The crystallite size of anode materials decreases with change of synthesis route. The highest conductivity is found to be 3.7 × 10−2 and 5.2 × 10−2 S cm−2 at 660 °C before and after reduction for CNP with suitable mechanical strength. The electrochemical performance of anode/electrolyte/anode interface of Cu0.5Ce0.5O2−δ is studied after reduction in presence of gas mixture (10%H2 + 90%N2) using electrochemical impedance spectroscopy. The conductivity for the Cell-800 prepared by CNP in presence of gas (10%H2 + 90%N2) shows lowest activation energy 1.28 eV. Thus, CNP is most promising method for obtaining the suitable anode material for the application of SOFC than Urea–Nitrate Process (UNP) and Glycine–Nitrate Process (GNP).

Books by Shabana Shaikh

Chemical Papers

This study primarily focused on the investigation, synthesis and analysis of lanthanum and tin py... more This study primarily focused on the investigation, synthesis and analysis of lanthanum and tin pyrochlores electrolytes for solid oxide fuel cell (SOFC) applications. Ceramic samples with diverse compositions of La 2−x Sr x Sn 2 O 7−δ (x = 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3) were synthesized by using solid-state reaction (SSR) methods. The prepared La 2−x Sr x Sn 2 O 7−δ samples were characterized by using X-ray diffraction, scanning electron microscopy and electrochemical impedance spectroscopy measurements. The results were further interpreted regarding the formation of high oxygen vacancy and structural disorder in the La 2−x Sr x Sn 2 O 7−δ matrix. The doping of lanthanum (La 3+) by strontium (Sr 2+) had a beneficial and remarkable effect on the structural and electrical properties: the increase in dopant (Sr) concentration decreased the lattice parameters of the crystalline phase and enhanced the creation of oxygen vacancies, which consequently increased the ionic conductivity and decreased the activation energy. Thus, it could be understood that the studied new La 2−x Sr x Sn 2 O 7−δ electrolyte would be one of the potential candidates for intermediate temperature SOFC applications.

This study primarily focused on the investigation, synthesis and analysis of lanthanum and tin py... more This study primarily focused on the investigation, synthesis and analysis of lanthanum and tin pyrochlores electrolytes for solid oxide fuel cell (SOFC) applications. Ceramic samples with diverse compositions of La 2−x Sr x Sn 2 O 7−δ (x = 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3) were synthesized by using solid-state reaction (SSR) methods. The prepared La 2−x Sr x Sn 2 O 7−δ samples were characterized by using X-ray diffraction, scanning electron microscopy and electrochemical impedance spectroscopy measurements. The results were further interpreted regarding the formation of high oxygen vacancy and structural disorder in the La 2−x Sr x Sn 2 O 7−δ matrix. The doping of lanthanum (La 3+) by strontium (Sr 2+) had a beneficial and remarkable effect on the structural and electrical properties: the increase in dopant (Sr) concentration decreased the lattice parameters of the crystalline phase and enhanced the creation of oxygen vacancies, which consequently increased the ionic conductivity and decreased the activation energy. Thus, it could be understood that the studied new La 2−x Sr x Sn 2 O 7−δ electrolyte would be one of the potential candidates for intermediate temperature SOFC applications.

Innovations in Microbiology and Biotechnology Vol. 4, 2022

Ba 0.3 Sr 0.7 Co 0.6 Fe 0.4 O 3-δ (BSCF3764) was synthesized via three different methods; solid s... more Ba 0.3 Sr 0.7 Co 0.6 Fe 0.4 O 3-δ (BSCF3764) was synthesized via three different methods; solid state reaction(SSR), glycine nitrate process(GNP), and EDTA-citric acid complexing sol-gel method (SG). Effect of preparation techniques on XRD, microstructure, 4-probe DC conductivity and transport properties using EIS were studied. Both, phase formation temperature and time of BSCF3764 synthesized by SG was found to be low as compared to other two methods. Grain size of around 0.2-0.3 µm in case of SSR and grown grains with size of approximately 0.1-0.2 µm along with pinholes. Composition synthesized by SG showed highest electrical conductivity at around 700 °C. The performance of BSCF3764 cathode on GDC (8020) electrolyte was dependent on the synthesis technique. The ASR values of BSCF3764 prepared by SSR, GNP and Sol-gel were found to be 1.567, 0.931 and 0.548 cm 2 at 700 °C. The cathode polarization resistance and activation energy was found to be minimum in BSCF3764 prepared by SG....

The samples belonging to Cu x Ce 1-x O 2-δ (x = 0.05, 0.1, 0.3, 0.4.0.5 and 0.6) series prepared ... more The samples belonging to Cu x Ce 1-x O 2-δ (x = 0.05, 0.1, 0.3, 0.4.0.5 and 0.6) series prepared by glycine-nitrate process (GNP) using copper nitrate, cerium nitrate and glycine as a fuel. The XRD confirms the formation of Cu x Ce 1-x O 2-δ. The solid solubility limit for Cu x Ce 1-x O 2-δ is up to x = 0.3. The crystallite size of anode materials decreases with the increasing content of Cu. The addition of Cu increases the porosity. The highest conductivity 3.4 × 10-2 Scm-1 is achieved for x = 0.6 and that of x = 0.5 is 2.5 × 10-2 Scm-1 at 660 ºC before reduction. It is found that from mechanical strength point of view Cu x Ce 1-x O 2-δ anode material for x = 0.5 is suitable than other compositions. The electrochemical performance and anode /electrolyte/anode interface of Cu x Ce 1-x O 2-δ anode is studied after reduction in 10%H 2 +90%N 2 and in humidified 10%H 2 +90%N 2 using impedance spectroscopy. The conductivity is maximum for the Cell-800 at Cell-700 ºC having lowest ASR 155...

International Journal of Hydrogen Energy, 2012

Solid oxide fuel cell Ba 0.5 Sr 0.5 Co 0.6 Fe 0.4 O 3Àd (BSCF5564) Scanning electron microscopy 4... more Solid oxide fuel cell Ba 0.5 Sr 0.5 Co 0.6 Fe 0.4 O 3Àd (BSCF5564) Scanning electron microscopy 4-Probe D.C. conductivity a b s t r a c t Ba 0.5 Sr 0.5 Co 0.6 Fe 0.4 O 3Àd (BSCF5564) was synthesized by nitric acid aided EDTAecitric acid complexing sol-gel method (NECC). Both, the phase formation temperature and time of BSCF5564 synthesized NECC were found to be low i.e. single perovskite phase formation temperature is 200 C less as compared to the conventional method of synthesis. The orthorhombic perovskite structure has been formed after calcination at 800 C for 5 h. Scanning electron microscopy reveals the formation of porous material constituting nanosized and irregularly shaped rod-like structure with particle size approximately ranges from 90 to 160 nm. The total weight loss of the BSCF5564 sample comes out to be 6.6%, indicating that quadrivalence state Co 4þ and Fe 4þ in the sample have been completely reduced to the trivalent state Co 3þ and Fe 3þ due to thermal analysis. The value of E a for BSCF5564 prepared by NECC was 0.2288 eV. The electrical conductivity of BSCF5564 synthesized by NECC is observed to be steady at high temperature (above 700 C).

RSC Advances

The gadolinium-doped ceria powder was synthesized using a microwave-synthesized glycine nitrate ... more The gadolinium-doped ceria powder was synthesized using a microwave-synthesized glycine nitrate process (MS-GNP).

ABSTRACT Fuel cells are electrochemical devices that convert chemical energy directly into electr... more ABSTRACT Fuel cells are electrochemical devices that convert chemical energy directly into electrical energy. All types are based on the same principles and have four basic components: electrolyte, anode, cathode, and interconnect. The different fuel cell types are categorized according to their electrolyte since it determines key features such as operating temperature, power-up time, type of fuel, migrating ions, and shock resistance. Fuel cells are generally utilized for secondary power generation, since in cases where they are not using fossil fuels – a possibility only for high temperature fuel cells – pure hydrogen has to be generated by using primary energy sources.Working fuel cell systems have already been developed by many companies in the automobile, electronics, and power generation industries. These systems have to be improved before they can compete on the market with existing technologies, by extending their lifetime and significantly reducing their cost. Two high temperature (solid oxide and molten carbonate) and two low temperature (polymer electrolyte and direct methanol) fuel cells are discussed in more detail, with a focus on the materials and the electrochemical reaction.

Advanced Ceramics and Applications

International Journal of Hydrogen Energy

Abstract The nanoparticles of Mn1.5[Cr(CN)6]∙mH2O@Ni1.5[Cr(CN)6]∙nH2O core-shell prussian blue an... more Abstract The nanoparticles of Mn1.5[Cr(CN)6]∙mH2O@Ni1.5[Cr(CN)6]∙nH2O core-shell prussian blue analogues (PBA) embedded with carbon additives (PBA-C) were synthesized and characterized as electrode material for solid state battery application. The impedance spectroscopy and cyclic voltametry were used to study the electrochemical properties by adding functionalized carbon in 1:1 proportion to improve the electrical performance. The value of room temperature electrical conductivity of core-shell PBA and core-shell nanoparticles mixed with vulcan carbon (PBA-C) are found to be 1.574 × 10−3 and 1.92 × 10−3 Scm−1, respectively. Using Li7La3Zr2O12 (LZZO) electrolyte, single cell was fabricated with PBA-C material, and studied its charging-discharging cycles, which exhibits higher current density with stable performance for 400 cycles for time slots of 400 min. The study reveals that the PBA core-shell nanoparticles mixed with carbon (PBA-C) may be a potential candidate as an electrode material in the form of a single cell using LZZO electrolyte.

Journal of Energy Storage

Abstract Energy demand is increasing in the present world where it is essential to explore altern... more Abstract Energy demand is increasing in the present world where it is essential to explore alternative energy resource that is clean, renewable and sustainable. Graphene is now receiving the great attention as it possesses excellent properties such as high charge mobility up to 230,000 cm2/Vs, 3000 W/m.K thermal conductivity, 2.3% absorption of visible light, strong mechanical strength of 130 GPa and high specific surface area of 2600 m2/g. These properties can be altered depending on synthesis techniques to obtain graphene such as; mechanical exfoliation, reduction of graphene oxide, chemical vapour deposition (CVD) and epitaxial growth of graphene. Furthermore, different characteristics of graphene can be employed for different applications in energy conversion and storage, for example, fuel cell and lithium ion battery. Hence, many studies were investigated to examine graphene and its applications. The objectives of this review is to understand and cover graphene background including properties and synthesis, which will help in understanding better the concept of graphene in its application such as in fuel cell and lithium ion batteries. In addition, it is showing the most key challenges and future consideration when nanostructured graphene is utilized.

Solid oxide fuel cell (SOFC) works by converting chemical energy into electrical energy due to re... more Solid oxide fuel cell (SOFC) works by converting chemical energy into electrical energy due to reforming, and it is one of the promising alternative source of energy for the future. In the present work, emphasis was given on increasing the electronic conductivity of anode material for SOFC. The Cu0.5Ce0.5O2-δ was prepared by mechanochemical (ball milling) route, with and without pore former. The effect of pore former on the electrical and structural characterization was studied in detail, and found that the Cu0.5Ce0.5O2-δ ceramic anode prepared by using pore former is more effective from structural and electrical points of view. The crystallite size is 58 nanoscales and DC conductivity after reduction is 9.50 ×10-1 Scm-2. Thus, the Cu0.5Ce0.5O2-δ prepared by ball milling using pore former technique could be an emerging potential anode material for SOFC.

Journal of Physics and Chemistry of Solids, 2016

Royal Society of Chemistry, 2020

The gadolinium-doped ceria Gd 0.1 Ce 0.9 O 1.95 (10GDC) powder was synthesized using a microwave-... more The gadolinium-doped ceria Gd 0.1 Ce 0.9 O 1.95 (10GDC) powder was synthesized using a microwave-synthesized glycine nitrate process (MS-GNP). The powder was subsequently pressed into circular pellets and sintered at various temperatures viz. 800, 900, 1000 and 1200 C, in a microwave, high temperature furnace for 4 h so as to investigate the effect of the sintering temperature and sintering environment on the structural, morphological, thermal and electrical properties. The crystallite size and particle size as observed from X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) are found to be in the range of 15-28 nm and 12-20 nm, respectively. The electrochemical impedance spectroscopy (EIS) analysis was carried out to study the electrochemical properties during the cooling cycle from 400 C to 800 C. The highest value of ionic conductivity (3.55 Â 10 À1 S cm À1) is observed at an operating temperature of 800 C and O 2 gas partial pressure of 1 atm. Further, it is observed that the sintering temperature has a significant effect on the surface morphology and crystallite size, thereby improving the electrical performance of the samples. Though 20GDC was used as an electrolyte in the authors' previous study, the novelty of the present work is the synthesis of 10GDC using a microwave-assisted glycine nitrate process and the size (thickness) of the prepared electrolyte for use in a Solid Oxide Fuel Cell (SOFC), which plays a major role in enhancing the structural, morphological and electrochemical properties with respect to different sintering temperatures as compared to the reported data. Hence, the prepared 10GDC electrolyte may be treated as one of the promising candidates as an electrolyte for SOFC for intermediate as well as high temperature applications.

In this study, (Bi 2 O 3 ) 1-x-y (Tb 4 O 7 ) x (Gd 2 O 3 ) y (xTbyGdSBi) ternary solid solutions ... more In this study, (Bi 2 O 3 ) 1-x-y (Tb 4 O 7 ) x (Gd 2 O 3 ) y (xTbyGdSBi) ternary solid solutions were synthesized via the solidstate synthesis technique. The phase structures of electrolytes were defined by X-ray powder diffraction (XRD) and differential thermal analysis/thermal gravimetric techniques (DTA/TG). The total electrical conductivity (σ T ) was measured with respect to the test temperature and doping concentration by using four-point probe technique (4PPT). Measurement results showed that δ-phase was obtained in test specimens and the conductivity of the electrolytes increased with increasing test temperature and decreasing amount of Gd 2 O 3. The 5Tb5GdSBi ternary system had the highest conductivity value of 3.88 × 10 −1 S cm −1 at 850°C. Compared to the literature, the results from this study are reasonably promising.

Renewable and Sustainable Energy Reviews, 2015

Solid-oxidefuelcells(SOFCs)arethemostwidelyusedfuelcellsbecausetheyexhibit flexibility,power gene... more Solid-oxidefuelcells(SOFCs)arethemostwidelyusedfuelcellsbecausetheyexhibit flexibility,power generationefficiency,andlowpollutionformation.ResearchonSOFCanodesisamajorandchallenging task inthe field ofSOFCs.ThisreviewhighlightstheanodematerialsthatmaybeusedforSOFC applications. Theuseofcermet-basedoxidematerialsasanodesforSOFCsisalsodiscussedindetail.A literaturesurveyconductedoverthelast10yearsshowsthatincreasedpowergenerationefficiency may be attributedtoanodematerialsusedinsuchcells.Oxide-basedanodematerialswithperovskiteand severaloxideswithcubic fluorite structuresarefurtherdescribed.Basedonthereviewconducted,we find thatcubic fluorite-structuredcompoundsarethemostpromisinganodematerialsreportedthusfar. Analysesofthestructureandelectricalperformanceofanodematerialsshowaswellthatcopper– gadolinium-doped ceriumoxide(Cu–GDC) cubic fluorite-structuredanodesexhibithigherelectronic conductivity potentialthanyttria-stabilizedzirconia-basedanodematerials. & 2015ElsevierLtd.Allrightsreserved.

International Journal of Hydrogen Energy, 2012

ABSTRACT The present work is focused on the comparative analysis of electrochemical and structura... more ABSTRACT The present work is focused on the comparative analysis of electrochemical and structural properties of anode materials for solid oxide fuel cells (SOFCs) and the influence of factors affected on electrode performance. The Cu0.5Ce0.5O2−δ was prepared by Citrate–Nitrate route (CNP) and its formation is confirmed by XRD. The crystallite size of anode materials decreases with change of synthesis route. The highest conductivity is found to be 3.7 × 10−2 and 5.2 × 10−2 S cm−2 at 660 °C before and after reduction for CNP with suitable mechanical strength. The electrochemical performance of anode/electrolyte/anode interface of Cu0.5Ce0.5O2−δ is studied after reduction in presence of gas mixture (10%H2 + 90%N2) using electrochemical impedance spectroscopy. The conductivity for the Cell-800 prepared by CNP in presence of gas (10%H2 + 90%N2) shows lowest activation energy 1.28 eV. Thus, CNP is most promising method for obtaining the suitable anode material for the application of SOFC than Urea–Nitrate Process (UNP) and Glycine–Nitrate Process (GNP).