The surface of austenitic stainless steel AISI 304L has been hardened by adding nitrogen and carb... more The surface of austenitic stainless steel AISI 304L has been hardened by adding nitrogen and carbon through the plasma nitrocarburizing process. Plasma nitrocarburizing at low temperatures eliminates the formation of nitrides and carbides of chromium, thereby increasing the surface hardness without compromising its corrosion resistance. This is attributed to the presence of a hard case consisting of a solid-solution of nitrogen and carbon occupying interstitial sites in an “expanded” austenite phase. The expanded austenite is further characterized as nitrogen-expanded austenite (γN) and carbon-expanded austenite (γC). In the present work, austenitic stainless steel AISI 304L samples were plasma nitrocarburized by varying the N2 content (%N2) in N2-H2-C2H2 feed gas mixture and treatment times (3, 5, and 7 h) at 673 K and 500 Pa. The samples were characterized by means of XRD, microindentation, XPS, EIS, and potentiodynamic polarization testing, for studying the microstructural, mecha...
In recent years, the mixed phosphates based polyanionic electrode materials have attracted great ... more In recent years, the mixed phosphates based polyanionic electrode materials have attracted great attention in sodium-ion batteries due to their structural stability during cycling and open framework for ion diffusion. Here, we report the electrochemical performance of Na4Co3(PO4)2P2O7/nitrogen doped carbon (NCPP/NC) composite as a negative electrode (anode) for sodium ion batteries in the working potential range of 0.01-3.0 V. It delivers a reversible discharge capacity of 250 mAhg −1 at 0.5 C current rate, which corresponds to the insertion/extraction of four sodium ions. The rate capability study indicates the reversible mechanism and highly stable capacity (61 mAhg −1) even at high rate up to 5 C as compared to pristine NCPP. The incorporation of the N doped carbon spheres in the composite is expected to enhance the electronic/ionic conductivity, which plays an important role in improving the performance and stability up to 400 cycles at 1 C rate. Intriguingly, the analysis of cyclic voltammetry data measured at different scan rates confirm the capacitive/diffusive controlled mechanism and the extracted diffusion coefficient is found to be around 10 −10 cm 2 s −1. Our results demonstrate that the NCPP/NC composite is also a potential candidate as anode in sodium-ion batteries due to its three dimensional framework, cost effectiveness, enhanced specific capacity as well as further possibility of improving the stability. I.
Lithium-sulfur (Li-S) batteries, regarded as one of the most promising alternatives to current st... more Lithium-sulfur (Li-S) batteries, regarded as one of the most promising alternatives to current state-of-the-art rechargeable Li-ion battery technologies, have received tremendous attention as potential candidates for next-generation portable electronics and the rapidly advancing EV market. However, substantial capacity decay, miserable cycle life, and meagre stability remained critical challenges. More specifically, shuttling of polysulfide [Li2Sx (3
Transition represents a comprehensive process of structural changes and transition "from socialis... more Transition represents a comprehensive process of structural changes and transition "from socialism to capitalism", i.e., the return to the market economy and the civil democracy. The transition process includes changes in all segments of society, especially in the reform of the political system. As a worldwide process it has begun in the '90s of the last century and it is still present in Bosnia and Herzegovina. The transition processes include a wide range of social and political changes, which are particularly obvious in the case of Bosnia and Herzegovina. In fact, not caring for the transition, for the need to change legislative framework in the first place, as well as existing institutions, various political options limitand restrain changes in social awareness. That all lead to the strengthening of the influence of particular interest groups, which ultimately prevent the completion of structural reforms, which have economic consequences for the whole country. In this context, the repressive state institutions without a clear vision and goal and without respect for the law and its own acts, perform activities associated with the various political options, while they have no responsibility for damage caused by such acts, both, individually to persons and to the community in general.
Journal of Materials Science: Materials in Electronics, 2021
Graphite is considered as an ideal anode material for lithium-ion battery (LIB) due to its high s... more Graphite is considered as an ideal anode material for lithium-ion battery (LIB) due to its high stability, good conductivity and wide source of availability. However, the low energy density and theoretical capacity of graphite cannot meet the needs of high performance anode materials. To circumvent this issue, alternative materials have been sought for many years now. Herein, we report the synthesis of highly crystalline lithium iron molybdate LiFe(MoO4)2 by combustion method and evaluated its performance as an anode material for lithium-ion batteries. Triclinic LiFe(MoO4)2 crystals having particle size 2–5 μm with good crystallinity were obtained. The material shows long cycle life and high rate performance than commercial graphite and exhibits first reversible discharge capacity of 931.6 mAh/g at a current density of 100 mA/g which is three times higher than commercial graphite. The high specific capacity together with the outstanding rate and cycle performance makes LiFe(MoO4)2 a promising anode material for LIB. A detailed analysis on the crystal structure and electronic properties of LiFe(MoO4)2 is presented based on DFT studies to complement the experimental observations.
Journal of the Taiwan Institute of Chemical Engineers, 2020
Abstract Exploring a safer replacement of Li metal anode is crucial for technological, and fundam... more Abstract Exploring a safer replacement of Li metal anode is crucial for technological, and fundamental importance. Li-metal is a preferred choice as anode material for lithium-ion battery (LIB) applications. However, parasitic dendritic growth on the Li metal surface during cycling causes instability and safety dreads. In the present study, we have investigated that the pre-lithiated ZnMoO4 is superior to its carbon-based counterparts (r-GO@ZnMoO4), moreover safer and sustainable than Li metal anode. The pre-lithiated ZnMoO4 delivers a better reversible capacity (∼1000 mAhg−1 at 0.1 Ag−1), superior rate capability (∼400 mAh g − 1 at 2 Ag−1), and excellent cycling stability over 300 cycles at 0.1 Ag−1, as compared to bare ZnMoO4 and r-GO@ZnMoO4 composite. The present investigation is an attempt to provide a substitute for commonly used Li-metal/carbon anodes with better performance.
Abstract A well-designed 3 dimensional (3D) nanocomposite foam of Co3O4 nanoparticles and functio... more Abstract A well-designed 3 dimensional (3D) nanocomposite foam of Co3O4 nanoparticles and functionalized carbon nano horns (CNH) is prepared by feasible wet chemistry followed by lyophilization. This 3D nanocomposite foam is evaluated electrochemically as anode material for lithium-ion battery (LIB). 3D hierarchical mesoporous hybrid of functionalized carbon nano horn-Co3O4 (CCO) shows excellent lithium storage properties with long cycle life due to high surface area, good conductivity, 3D interconnected mesoporous structure, mechanical and chemical stability and shortened diffusion path length for Li+ ions during lithiation-delithiation. The Co3O4 nanoparticles incorporated into interconnected CNH foam effectively increases the number of active sites of CCO nanocomposite and consequently increase in the reversible specific capacity and coulombic efficiency. Different compositions of CNH foam with Co3O4 nanoparticles are prepared, among which the CCO 1:1 foam displays reversible capacity of 797 mAhg−1 at current density of 0.1 Ag−1 along with excellent rate performance. High specific capacity of around 702 mAhg−1 is obtained even at the current density of 5 Ag−1.
For next generation, lithium-ion batteries (LIBs) developing high capacity anode materials are cr... more For next generation, lithium-ion batteries (LIBs) developing high capacity anode materials are crucial with increasing demand of large-scale application. Conversion-type anode materials are promising if stable cycling behavior could be achieved. In this work, a nitrogen-doped porous carbon-Fe3O4 (NPC-Fe3O4) nanocomposite is synthesized via a simple and scalable approach. Composite is prepared by pyrolysis of polymer silica hybrid PolyHIPE (high internal phase emulsion) into NPC, and Fe3O4 nanoparticles (NPs) are anchored on its surface via hydrothermal synthesis. As-prepared NPC-Fe3O4 nanocomposite delivers high reversible capacity of around 1001 mAhg−1 at 0.1 Ag−1 current density and rate capabilities and displays excellent cycling stability as high as 95% capacity retention even after 400 cycles. Superior electrochemical performance of NPC-Fe3O4 is attributed to the hierarchical porous structure and nitrogen doping of carbon which shorten the diffusion path of Li+ and provide ample space to prevent aggregation of Fe3O4 nanoparticles.
Anodes with improved Li storage capability are required for next-generation lithium batteries. In... more Anodes with improved Li storage capability are required for next-generation lithium batteries. In this paper we report a convenient synthesis strategy, based on electrospinning followed by reductio...
An experimental and computational study of nanocomposite anodes comprising Co3O4 nanoparticles de... more An experimental and computational study of nanocomposite anodes comprising Co3O4 nanoparticles decorated on nitrogen and sulphur co-doped carbon spheres for appliction in LIBs.
An effective and straightforward route for tailoring the self-supporting, exfoliated flexible gra... more An effective and straightforward route for tailoring the self-supporting, exfoliated flexible graphite substrate (E-FGS) using electrochemical anodization is proposed. E-FGS has essential features of highly exfoliated, few-layered, two-dimensional graphite sheets with the size of several tens of micrometers, interconnected along the axis of the substrate surface. The novel hierarchical porous structural morphology of E-FGS enables large active sites for efficient electrolyte ion and charge transport when used as electrode material for a supercapacitor. In order to effectively utilize this promising E-FGS electrode for energy storage purpose, a ternary composite is further synthesized with pseudocapacitive polyhydroquinone (PHQ) and hydrous RuO2 (hRO). hRO is synthesized via a sol-gel route, while electropolymerization is utilized for the electrodeposition of PHQ over E-FGS. Ultimately, the fabricated self-supporting E-FGS-based flexible supercapacitor is capable of delivering areal specific capacitance values as high as 378 mF cm-2 at a current density of 1 mA cm-2. Addition of the pseudocapacitive component to the E-FGS texture leads to ∼10 times increase of the electrochemical charge storage capability. The imposition of mechanical forces to this flexible supercapacitor device results in trivial changes in electrochemical properties and is still capable of retaining 91% of the initial specific capacitance after 10 000 cycles. Alongside, the fabricated symmetrical solid-state flexible device exhibited a high energy density of 8.4 μWh cm-2. The excellent performance along with the ease of synthesis and fabrication process of the flexible solid-state supercapacitor device using PHQ/hRO/E-FGS holds promise for large-scale production.
Environmental Chemistry for a Sustainable World, 2019
As a consequence to the remarkable development of the science and technology, an exponential dema... more As a consequence to the remarkable development of the science and technology, an exponential demand for energy leads to the exploitation of nonrenewable energy sources including fossil fuel paves the way to stern environmental crises. Global warming is one of the principal threats, due to the accumulation of greenhouse gases, resulting from the use of fossil fuels. Because of limited availability, the fossil fuels have been rapidly exhausting, compelling researchers to accelerate the search for environment-friendly, renewable, and sustainable energy sources like the solar cell, wind, and electrochemical energy storage systems. Electrochemical energy storage systems (EESs), more specifically rechargeable batteries and supercapacitors being efficient alternatives, have attracted tremendous attention. Rechargeable batteries not only serve as energy storage devices but also capable of providing the dispatchable energy for transportation, i.e., electrical vehicles (EVs and hybrid EVs).
Bimetallic dendrites (Au, Ag, Pt, Pd) have received intense research interest due to their applic... more Bimetallic dendrites (Au, Ag, Pt, Pd) have received intense research interest due to their applications in catalysis and sensing. However, reports on rational synthesis of non-noble bimetallic dendrites that finds self-cleaning applications are scanty. Here, we demonstrate one step co-reduction based galvanic replacement reaction (GRR) for synthesis of alloyed bimetallic dendrites (CuSn, CuNi) with controlled surface roughness and chemical composition. Probing their growth process reveals that i) for CuSn dendrites, co-reduction of Cu2+ and Sn2+ is observed throughout GRR; ii) for CuNi dendrites, Cu nanoparticle, that deposits initially, augments the reduction of Ni2+ which leads to CuNi alloy phase formation during later stages of GRR. These dendrites, naturally having dual degree of surface roughness (micro/nano), have been exploited here for fabricating superhydrophobic surfaces (SHS) with excellent self-cleaning abilities. They show enabling properties such as high contact angle, minimal contact angle hysteresis, and excellent Cassie state stability with no impalement. They maintain superhydrophobicity when exposed to different environmental conditions (low temperature, high temperature, exposure to corroding solutions and UV radiation). The present facile methodology for fabrication of bimetallic dendrites is beneficial for low-cost production of functional nano/micro-materials.
Abstract TiO2 is a good alternative anode material for lithium-ion battery application because of... more Abstract TiO2 is a good alternative anode material for lithium-ion battery application because of its incomparable high structural stability and safety during the charge/discharge cycles. However, the low intrinsic conductivity of TiO2 has been a limiting factor affecting its cycling and rate capability performance. Here in this work, we present Co-doped TiO2 nanoparticles based anode with good reversibility, cycling stability and rate capability performance for its envisaged application in lithium-ion battery. The Co-doped TiO2 nanoparticles with different Co concentrations (3%, 5%, and 7%) are synthesized using simple and economic biomediated green approach, wherein TiCl4 and Co precursors are allowed to react in Bengal gram bean extract containing biomolecules which act as natural capping agents to control the size of nanoparticles. Among the pure TiO2 and different Co-doped TiO2 samples, the 7% Co-doped TiO2 anode show the highest capacity of 167 mAh g−1 (88.3%) after 100 cycles at the 0.5C current density. The Co-doped TiO2 shows higher and stable coulombic efficiency up to 100 GCD cycles indicating good reversibility. Based on the results, it is expected that the Co-doped TiO2 nanoparticles might be contributing to the enhanced electronic conductivity providing an efficient pathway for fast electron transfer.
The surface of austenitic stainless steel AISI 304L has been hardened by adding nitrogen and carb... more The surface of austenitic stainless steel AISI 304L has been hardened by adding nitrogen and carbon through the plasma nitrocarburizing process. Plasma nitrocarburizing at low temperatures eliminates the formation of nitrides and carbides of chromium, thereby increasing the surface hardness without compromising its corrosion resistance. This is attributed to the presence of a hard case consisting of a solid-solution of nitrogen and carbon occupying interstitial sites in an “expanded” austenite phase. The expanded austenite is further characterized as nitrogen-expanded austenite (γN) and carbon-expanded austenite (γC). In the present work, austenitic stainless steel AISI 304L samples were plasma nitrocarburized by varying the N2 content (%N2) in N2-H2-C2H2 feed gas mixture and treatment times (3, 5, and 7 h) at 673 K and 500 Pa. The samples were characterized by means of XRD, microindentation, XPS, EIS, and potentiodynamic polarization testing, for studying the microstructural, mecha...
In recent years, the mixed phosphates based polyanionic electrode materials have attracted great ... more In recent years, the mixed phosphates based polyanionic electrode materials have attracted great attention in sodium-ion batteries due to their structural stability during cycling and open framework for ion diffusion. Here, we report the electrochemical performance of Na4Co3(PO4)2P2O7/nitrogen doped carbon (NCPP/NC) composite as a negative electrode (anode) for sodium ion batteries in the working potential range of 0.01-3.0 V. It delivers a reversible discharge capacity of 250 mAhg −1 at 0.5 C current rate, which corresponds to the insertion/extraction of four sodium ions. The rate capability study indicates the reversible mechanism and highly stable capacity (61 mAhg −1) even at high rate up to 5 C as compared to pristine NCPP. The incorporation of the N doped carbon spheres in the composite is expected to enhance the electronic/ionic conductivity, which plays an important role in improving the performance and stability up to 400 cycles at 1 C rate. Intriguingly, the analysis of cyclic voltammetry data measured at different scan rates confirm the capacitive/diffusive controlled mechanism and the extracted diffusion coefficient is found to be around 10 −10 cm 2 s −1. Our results demonstrate that the NCPP/NC composite is also a potential candidate as anode in sodium-ion batteries due to its three dimensional framework, cost effectiveness, enhanced specific capacity as well as further possibility of improving the stability. I.
Lithium-sulfur (Li-S) batteries, regarded as one of the most promising alternatives to current st... more Lithium-sulfur (Li-S) batteries, regarded as one of the most promising alternatives to current state-of-the-art rechargeable Li-ion battery technologies, have received tremendous attention as potential candidates for next-generation portable electronics and the rapidly advancing EV market. However, substantial capacity decay, miserable cycle life, and meagre stability remained critical challenges. More specifically, shuttling of polysulfide [Li2Sx (3
Transition represents a comprehensive process of structural changes and transition "from socialis... more Transition represents a comprehensive process of structural changes and transition "from socialism to capitalism", i.e., the return to the market economy and the civil democracy. The transition process includes changes in all segments of society, especially in the reform of the political system. As a worldwide process it has begun in the '90s of the last century and it is still present in Bosnia and Herzegovina. The transition processes include a wide range of social and political changes, which are particularly obvious in the case of Bosnia and Herzegovina. In fact, not caring for the transition, for the need to change legislative framework in the first place, as well as existing institutions, various political options limitand restrain changes in social awareness. That all lead to the strengthening of the influence of particular interest groups, which ultimately prevent the completion of structural reforms, which have economic consequences for the whole country. In this context, the repressive state institutions without a clear vision and goal and without respect for the law and its own acts, perform activities associated with the various political options, while they have no responsibility for damage caused by such acts, both, individually to persons and to the community in general.
Journal of Materials Science: Materials in Electronics, 2021
Graphite is considered as an ideal anode material for lithium-ion battery (LIB) due to its high s... more Graphite is considered as an ideal anode material for lithium-ion battery (LIB) due to its high stability, good conductivity and wide source of availability. However, the low energy density and theoretical capacity of graphite cannot meet the needs of high performance anode materials. To circumvent this issue, alternative materials have been sought for many years now. Herein, we report the synthesis of highly crystalline lithium iron molybdate LiFe(MoO4)2 by combustion method and evaluated its performance as an anode material for lithium-ion batteries. Triclinic LiFe(MoO4)2 crystals having particle size 2–5 μm with good crystallinity were obtained. The material shows long cycle life and high rate performance than commercial graphite and exhibits first reversible discharge capacity of 931.6 mAh/g at a current density of 100 mA/g which is three times higher than commercial graphite. The high specific capacity together with the outstanding rate and cycle performance makes LiFe(MoO4)2 a promising anode material for LIB. A detailed analysis on the crystal structure and electronic properties of LiFe(MoO4)2 is presented based on DFT studies to complement the experimental observations.
Journal of the Taiwan Institute of Chemical Engineers, 2020
Abstract Exploring a safer replacement of Li metal anode is crucial for technological, and fundam... more Abstract Exploring a safer replacement of Li metal anode is crucial for technological, and fundamental importance. Li-metal is a preferred choice as anode material for lithium-ion battery (LIB) applications. However, parasitic dendritic growth on the Li metal surface during cycling causes instability and safety dreads. In the present study, we have investigated that the pre-lithiated ZnMoO4 is superior to its carbon-based counterparts (r-GO@ZnMoO4), moreover safer and sustainable than Li metal anode. The pre-lithiated ZnMoO4 delivers a better reversible capacity (∼1000 mAhg−1 at 0.1 Ag−1), superior rate capability (∼400 mAh g − 1 at 2 Ag−1), and excellent cycling stability over 300 cycles at 0.1 Ag−1, as compared to bare ZnMoO4 and r-GO@ZnMoO4 composite. The present investigation is an attempt to provide a substitute for commonly used Li-metal/carbon anodes with better performance.
Abstract A well-designed 3 dimensional (3D) nanocomposite foam of Co3O4 nanoparticles and functio... more Abstract A well-designed 3 dimensional (3D) nanocomposite foam of Co3O4 nanoparticles and functionalized carbon nano horns (CNH) is prepared by feasible wet chemistry followed by lyophilization. This 3D nanocomposite foam is evaluated electrochemically as anode material for lithium-ion battery (LIB). 3D hierarchical mesoporous hybrid of functionalized carbon nano horn-Co3O4 (CCO) shows excellent lithium storage properties with long cycle life due to high surface area, good conductivity, 3D interconnected mesoporous structure, mechanical and chemical stability and shortened diffusion path length for Li+ ions during lithiation-delithiation. The Co3O4 nanoparticles incorporated into interconnected CNH foam effectively increases the number of active sites of CCO nanocomposite and consequently increase in the reversible specific capacity and coulombic efficiency. Different compositions of CNH foam with Co3O4 nanoparticles are prepared, among which the CCO 1:1 foam displays reversible capacity of 797 mAhg−1 at current density of 0.1 Ag−1 along with excellent rate performance. High specific capacity of around 702 mAhg−1 is obtained even at the current density of 5 Ag−1.
For next generation, lithium-ion batteries (LIBs) developing high capacity anode materials are cr... more For next generation, lithium-ion batteries (LIBs) developing high capacity anode materials are crucial with increasing demand of large-scale application. Conversion-type anode materials are promising if stable cycling behavior could be achieved. In this work, a nitrogen-doped porous carbon-Fe3O4 (NPC-Fe3O4) nanocomposite is synthesized via a simple and scalable approach. Composite is prepared by pyrolysis of polymer silica hybrid PolyHIPE (high internal phase emulsion) into NPC, and Fe3O4 nanoparticles (NPs) are anchored on its surface via hydrothermal synthesis. As-prepared NPC-Fe3O4 nanocomposite delivers high reversible capacity of around 1001 mAhg−1 at 0.1 Ag−1 current density and rate capabilities and displays excellent cycling stability as high as 95% capacity retention even after 400 cycles. Superior electrochemical performance of NPC-Fe3O4 is attributed to the hierarchical porous structure and nitrogen doping of carbon which shorten the diffusion path of Li+ and provide ample space to prevent aggregation of Fe3O4 nanoparticles.
Anodes with improved Li storage capability are required for next-generation lithium batteries. In... more Anodes with improved Li storage capability are required for next-generation lithium batteries. In this paper we report a convenient synthesis strategy, based on electrospinning followed by reductio...
An experimental and computational study of nanocomposite anodes comprising Co3O4 nanoparticles de... more An experimental and computational study of nanocomposite anodes comprising Co3O4 nanoparticles decorated on nitrogen and sulphur co-doped carbon spheres for appliction in LIBs.
An effective and straightforward route for tailoring the self-supporting, exfoliated flexible gra... more An effective and straightforward route for tailoring the self-supporting, exfoliated flexible graphite substrate (E-FGS) using electrochemical anodization is proposed. E-FGS has essential features of highly exfoliated, few-layered, two-dimensional graphite sheets with the size of several tens of micrometers, interconnected along the axis of the substrate surface. The novel hierarchical porous structural morphology of E-FGS enables large active sites for efficient electrolyte ion and charge transport when used as electrode material for a supercapacitor. In order to effectively utilize this promising E-FGS electrode for energy storage purpose, a ternary composite is further synthesized with pseudocapacitive polyhydroquinone (PHQ) and hydrous RuO2 (hRO). hRO is synthesized via a sol-gel route, while electropolymerization is utilized for the electrodeposition of PHQ over E-FGS. Ultimately, the fabricated self-supporting E-FGS-based flexible supercapacitor is capable of delivering areal specific capacitance values as high as 378 mF cm-2 at a current density of 1 mA cm-2. Addition of the pseudocapacitive component to the E-FGS texture leads to ∼10 times increase of the electrochemical charge storage capability. The imposition of mechanical forces to this flexible supercapacitor device results in trivial changes in electrochemical properties and is still capable of retaining 91% of the initial specific capacitance after 10 000 cycles. Alongside, the fabricated symmetrical solid-state flexible device exhibited a high energy density of 8.4 μWh cm-2. The excellent performance along with the ease of synthesis and fabrication process of the flexible solid-state supercapacitor device using PHQ/hRO/E-FGS holds promise for large-scale production.
Environmental Chemistry for a Sustainable World, 2019
As a consequence to the remarkable development of the science and technology, an exponential dema... more As a consequence to the remarkable development of the science and technology, an exponential demand for energy leads to the exploitation of nonrenewable energy sources including fossil fuel paves the way to stern environmental crises. Global warming is one of the principal threats, due to the accumulation of greenhouse gases, resulting from the use of fossil fuels. Because of limited availability, the fossil fuels have been rapidly exhausting, compelling researchers to accelerate the search for environment-friendly, renewable, and sustainable energy sources like the solar cell, wind, and electrochemical energy storage systems. Electrochemical energy storage systems (EESs), more specifically rechargeable batteries and supercapacitors being efficient alternatives, have attracted tremendous attention. Rechargeable batteries not only serve as energy storage devices but also capable of providing the dispatchable energy for transportation, i.e., electrical vehicles (EVs and hybrid EVs).
Bimetallic dendrites (Au, Ag, Pt, Pd) have received intense research interest due to their applic... more Bimetallic dendrites (Au, Ag, Pt, Pd) have received intense research interest due to their applications in catalysis and sensing. However, reports on rational synthesis of non-noble bimetallic dendrites that finds self-cleaning applications are scanty. Here, we demonstrate one step co-reduction based galvanic replacement reaction (GRR) for synthesis of alloyed bimetallic dendrites (CuSn, CuNi) with controlled surface roughness and chemical composition. Probing their growth process reveals that i) for CuSn dendrites, co-reduction of Cu2+ and Sn2+ is observed throughout GRR; ii) for CuNi dendrites, Cu nanoparticle, that deposits initially, augments the reduction of Ni2+ which leads to CuNi alloy phase formation during later stages of GRR. These dendrites, naturally having dual degree of surface roughness (micro/nano), have been exploited here for fabricating superhydrophobic surfaces (SHS) with excellent self-cleaning abilities. They show enabling properties such as high contact angle, minimal contact angle hysteresis, and excellent Cassie state stability with no impalement. They maintain superhydrophobicity when exposed to different environmental conditions (low temperature, high temperature, exposure to corroding solutions and UV radiation). The present facile methodology for fabrication of bimetallic dendrites is beneficial for low-cost production of functional nano/micro-materials.
Abstract TiO2 is a good alternative anode material for lithium-ion battery application because of... more Abstract TiO2 is a good alternative anode material for lithium-ion battery application because of its incomparable high structural stability and safety during the charge/discharge cycles. However, the low intrinsic conductivity of TiO2 has been a limiting factor affecting its cycling and rate capability performance. Here in this work, we present Co-doped TiO2 nanoparticles based anode with good reversibility, cycling stability and rate capability performance for its envisaged application in lithium-ion battery. The Co-doped TiO2 nanoparticles with different Co concentrations (3%, 5%, and 7%) are synthesized using simple and economic biomediated green approach, wherein TiCl4 and Co precursors are allowed to react in Bengal gram bean extract containing biomolecules which act as natural capping agents to control the size of nanoparticles. Among the pure TiO2 and different Co-doped TiO2 samples, the 7% Co-doped TiO2 anode show the highest capacity of 167 mAh g−1 (88.3%) after 100 cycles at the 0.5C current density. The Co-doped TiO2 shows higher and stable coulombic efficiency up to 100 GCD cycles indicating good reversibility. Based on the results, it is expected that the Co-doped TiO2 nanoparticles might be contributing to the enhanced electronic conductivity providing an efficient pathway for fast electron transfer.
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Papers by Pravin Dwivedi