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Hydrothermally synthesized mesoporous carbon coated SnO2 nanoparticles (NPs) with numerous oxygen vacancies as a promising anode for lithium ion battery applications.

A wet chemical dispersion followed by annealing synthesis strategy enables the development of a low-cost metal oxide-based composite anode material.

In the present study, an earth-abundant bio-waste is effectively transformed into porous graphene sheets at a low temperature of 900 °C by utilizing Potassium hydroxide (KOH) as an activation agent to create porosity as well as a catalyst to induce graphitization by a simple synthetic approach. The resulted carbon material possesses good textural properties such as high specific surface area (2308 m2/g), high pore volume (1.3 cm3/g), graphene sheet-like morphology with an interlayer d-spacing of 0.345 nm and a highly ordered sp2 carbon as evidenced from detailed textural analysis. A detailed mechanism for the formation of graphene sheets is further explored. Owing to the multiple synergistic properties, the material has been tested as an efficient electrode material for supercapacitor application and it delivered a high specific capacitance of 240 F g−1 at 1 A/g. Furthermore, the assembled symmetric supercapacitor exhibits ultra-fast rate capability of 87% capacitance retention at high current rates (50 A/g), exceptional cyclic stability (93% retention after 25,000 cycles) and displays outstanding energy density of 21.37 W h kg−1 at a high power density of 13,420 W kg−1. The strategy developed here reveals a facile, low-cost, eco-friendly design of graphene sheets at large scale production, where the synthetic approach can be applied as a versatile method to prepare graphene sheets from any carbon sources using KOH activation.

Lithium-ion capacitors (LICs) with the capability of high energy and high power are considered to be attractive for advanced energy storage applications. However, the design and fabrication of suitable electrode materials with desirable properties by a facile approach using cost-effective precursors are still a great challenge. In this work, we have utilized petroleum coke, an unavoidable industrial waste with high carbon content, as a single carbon source to synthesize both a high surface area activated carbon cathode and a low surface area disordered carbon anode. A lithium-ion capacitor fabricated using all-petroleum coke-derived carbon materials exhibits a high energy density of 80 W h/kg and a high power density of 8.4 kW/kg as well as long life span (85% capacity retention after 10,000 charge–discharge cycles at 1 A/g). Systematic characterization analysis demonstrates that unique characteristics of carbon electrode materials including hierarchical pores, high surface area, and graphene-like structured activated carbon contribute synergistically to the outstanding performance of the petroleum coke-based LIC. More importantly, the facile approach adopted in the present study to synthesize both cathode and anode materials from a single source is an effective way for high value-added utilization of petroleum coke at the commercial level.

Micro- and mesoporous graphitic carbon sheets (MGC) were synthesized from jute sticks (bio-waste) and employed as an efficient polysulfide inhibitor for sulfur cathode in a lithium–sulfur battery application. The as-prepared MGC possesses sheet-like morphological characteristics with unique textural properties such as high specific surface area (2047 m2 g−1), large pore volume (1.69 cc3 g−1) and has excellent graphitic carbon structures. Studies were made in order to optimize the sulfur loading into MGC and to modify the polypropylene separator by coating with a thin layer of as-prepared MGC to attain enhanced electrochemical performance. The optimized sulfur loaded MGC/S-2 cathode with modified separator delivered a high initial discharge capacity of 1542 mAh g−1 and retained a discharge capacity of 1016 mAh g−1 after 50 cycles at 0.2 C rate, attributed to high surface area and porosity of MGC, which act as host as well as barrier film that inhibits the migration of dissolved polysulfide species to the anode during the redox process. Furthermore, the novel cell configuration with modified separator renders high sulfur loading up to 9.3 mg cm−2 and the resulting cell delivered a high discharge capacity of 632 mAh g−1 at 0.2 C rate even at 50th cycle.

The combined approach of bulk doping and surface modification seems to be rational wherein, the dopant acts as visible light absorber and the surface grafted ion acts as co-catalyst to trap the photo-excited electron. Recently, it was established that if the doped energy levels are similar to the surface energy levels, charge transfer from these doped states to the surface states is enhanced based on the concept of energy level matching. Silver (Ag), whose doped and modified levels are almost similar must exhibit this concept of energy level matching and in fact, a combination of doping and surface modification, i.e. Ag-doped Ag-modified TiO2 gave better results when compared to individually doped or modified samples. Upon photocatalyst excitation, the photo-generated electrons in the TiO2 valence band are excited to the dopant Ag 4d states (0.76 eV below the conduction band) from where they are further transferred to the surface states of Ag and later consumed for the reduction of oxygen through multi-electron reduction leading to an enhancement in the photocatalytic activity. The photocatalysts prepared by this concept of energy level matching have been tested for various self-cleaning applications like decomposition of acetaldehyde and degradation of methylene blue under visible-light illumination.

In the present study, we have developed a simple and cost-effective approach for the synthesis of carbon coated LiFePO₄ wherein different carbon precursors were used to find out the suitable precursor for carbon coating. Initially, the appropriate amount of Li, Fe, and P precursors and carbon source (glucose/sucrose/fructose) were dissolved in ethanol solution followed by hydrothermal treatment at 180 °C to obtain carbon coated LiFePO₄. The structure and morphological analysis of In-Situ carbon coated LiFePO₄ revealed the formation of thin and homogeneous carbon layer on crystalline single-phase LiFePO₄ particles with fructose used as carbon precursor. Raman analysis confirms the presence of more ordered graphitic carbon and the ID/IG ratio is 1.01, 0.69 and 0.87 for C-LFP-S, C-LFP-F and C-LFP-G respectively, indicating that fructose assisted In-Situ carbon coating leads to the formation of more ordered carbon coating on LiFePO₄ with high graphitization degree in comparison with carbon coating by glucose and sucrose. HR-TEM results revealed the presence of uniform carbon distribution, which encapsulates the crystalline LiFePO₄ particles forming a core-shell structure in the presence of fructose as carbon precursor. C-LFP-S delivered a capacity of 125 mAh/g at 0.1 C rate but then due to non-uniform carbon layer distribution, the capacity faded out completely when tested at higher C-rates. Whereas C-LFP-F delivered a discharge capacity of 98 mAh/g at 0.1 C and 48 mAh/g at 1 C, which is promising compared to the LiFePO₄ carbon coated using sucrose and glucose. It is concluded that LiFePO₄ carbon coated using monosacrides as carbon precursors showed better electro-chemical performance in terms of capacity and cyclic stability when compared to LiFePO₄ carbon coated using dissacrides, attributing that uniform, thin layer, and highly ordered graphitic carbon coverage on nano sized LiFePO₄ particles greatly reduces the polarization resistance and hence improving the electrochemical performance of C-LFP-F.

In the present study, we report the synthesis of porous graphitic carbon sheets (GCS) from tissue paper by in-situ chemical activation process. The resulting GCS material characterized with high graphitic structure and high specific surface area (1684 m2 g−1). When GCS-2 electrode tested for supercapacitor application, it delivers a high specific capacitance of 212 F g−1, high capacitance retention of 85% at high current density of 50 A g−1 and outstanding cyclic stability (90% capacity retention after 10,000 cycles). The fabricated supercapacitor cells were also demonstrated for lightening 40 LEDs. The high electrochemical performance of GCS can be attributed to the high specific surface area, large pore volume and graphitic nature of the carbon. Thus, the simple and unique strategy employed in the present study can be extended to synthesize carbon materials from other economic carbon precursors suitable for other energy storage applications.

In this study, we adopted a simple method to synthesize a graphene-like-structured nanoporous carbon using a jute stick as a carbon precursor and studied the electrochemical properties for supercapacitors. The synthesized nanoporous carbon is composed of a graphene sheet-like network and amorphous carbon, and the ratio between these two components is tuned by the activation temperature. As the activation temperature is increased, the amorphous carbon is converted into a stable graphene-like network with a high specific surface area of 2396 m2/g, with a graphene sheet-like morphology and a highly ordered graphitic sp2 carbon. For supercapacitor application, the nanoporous carbon is studied in aqueous as well as organic electrolytes, and the material shows excellent electrochemical performance in both the cases. It exhibited a high specific capacitance of 282 F/g and shows excellent rate capability with almost 70% capacitance retention at high current rates. Furthermore, the assembled symmetric supercapacit...

A polished rutile TiO2 (001) surface was annealed at 410 °C and studied using low-energy electron diffraction (LEED) and surface X-ray diffraction (SXRD). The LEED pattern revealed a (1 × 1) structure. The crystal truncation rods (CTRs) obtained using SXRD were analyzed to reveal the structure of the annealed TiO2 (001) surface. We found that about 40% of the surface was flat and the remaining 60% consisted of facets. The facets were mainly {011}-oriented. They were three layers deep and contained no terraces. It was reported that TiO2 (001) surface annealed at 410 °C exhibited more moderate photocatalytic activity than the HF-treated surface. Comparing these results, it was concluded that the formation of {011} facet lowered the photocatalytic activity of annealed TiO2 (001) surface than as-received surface.

This book chapter deals with semiconductor bandgap engineering, especially the conduction band which develops photocatalytic activity under visible light illumination. Energy-level matching as a new concept is explained and the potential advantages of this concept for self-cleaning applications such as, volatile organic compounds (VOC) degradation, dye degradation and deactivation of pathogens are highlighted.

Efforts made in this current study focus on the development of a novel, simple, cost-effective yet efficient approach to synthesize nanoporous carbon material from corn silk biomass for supercapacitor applications. We have employed different activation approaches in order to obtain a higher surface area and large mesoporous volume fraction. The performance of corn silks derived nanoporous activated carbon materials for supercapacitor applications was evaluated in a symmetric two electrode configuration using aqueous/non-aqueous electrolytes at various current densities and scan rates. Electrochemical results indicated that the as-synthesized nanoporous carbon prepared by single step activation exhibits ideal supercapacitor performance ∼160 F/g (at 1 A/g current density) with excellent rate capability and cyclic stability. Further, it displayed a promising amount of energy that can be stored in a given mass ∼32.28 Wh/kg at the power density of 870.68 W/kg. Benchmark studies revealed that the nanoporous carbon developed in the current study is at par with the performance of the commercial carbon electrode. The superior performance of corn silks derived nanoporous carbon is attributed to high surface area pertaining to its unique mesoporous fiber-like morphology, which facilitates fast ionic and electronic diffusion of the electrolyte into and out of the pores during charging and discharging.

A one-step in-situ activation process has been adopted for the synthesis of micro and mesoporous carbon from neem leaves for use as a matrix for a sulfur cathode. The neem leaf micro and mesoporus ...

A smart, efficient and cost-effective strategy using modified evaporation induced self-assembly (EISA) is employed to synthesize mesoporous carbon (MC) with excellent textural parameters. Furfuryl alcohol is utilized as an alternative source of carbon precursor for the first time in EISA process in place of conventional EISA precursor, namely resol. Further n-Butanol, used as a co-structure directing agent during synthesis plays a crucial role in formation of a high surface area mesoporous carbon. The resulting carbon synthesized by modified EISA process shows a high specific surface area with large pore volume and more of ordered graphitic carbon. Wettability studies reveal that the surface functionalized mesoporous carbon film surface exhibits superior hydrophilic properties in comparison with non-functionalized mesoporous carbon film surface. It delivers a high specific capacitance of 151 F g−1 at a high current density of 50 A g−1 and shows excellent rate capability with 93% capacitance retention. It also exhibits good cyclic stability with capacitance retention of 96% after 10,000 cycles and delivers a stable energy density of 2.7 W h kg−1 by retaining a power density of 2516 W kg−1. The excellent electro-chemical performance of mesoporous carbon reported in the present study is attributed to the presence of high surface area of MC with large interconnected mesopores that allows unhindered flow of the electrolyte ions to the active surface sites. Benchmark studies reveal that the electro-chemical performance of mesoporous carbon being reported in this study is better than carbon electrode based commercial supercapacitors. Thus, the simple and unique strategy employed in the present study can be extended to synthesize carbon materials for other energy storage applications.

Nitrogen-doped nanoporous activated carbon is considered as exciting material for energy storage applications owing to its ordered atomic arrangement and high electrical conductivity. In the present study, we focus on synthesizing cork derived activated carbon (CAC) using bio-waste (cork) by adopting melamine assisted chemical reaction in which three different stoichiometric ratios of cork carbon to melamine are used (1:1, 1:5, 1:10). As synthesized, nitrogen-doped carbons are further activated by a chemical method later to induce porosity. The XRD and Raman spectroscopic measurements revealed the presence of highly ordered graphitic carbon with few-layered graphene-like structure after chemical activation process. among the carbon materials, CAC with a 1:1 (Carbon/melamine) ratio possess a unique honeycomb structure and exhibits a hierarchical micro to mesoporous nature with a high surface area (1378 m2/g), large pore volume (0.8 cm3/g) and average pore diameter of 3.1 nm. The resulting material with 4.38 wt.% of nitrogen content delivers capacitance of 133 F/g for supercapacitor application and its performance is on par with commercial YP-50F (102 F/g) at a current density of 1 A/g in 1 M TEABF4/AN between the potential window of 0–3 V. Further it displays an outstanding rate capability (i.e., 65 F/g at 20 A/g) and long cyclic stability (98% capacity retention after 10,000 cycles) by maintaining a specific energy of 42 Wh/Kg with a specific power of 750 W/Kg. The 3D inter-connected honeycomb-like structure with superior textural parameters (higher-surface area, large pore volumes, hierarchical pores and high graphitic nature) and nitrogen doping significantly contributed to the improved efficiency of CAC for Supercapacitor application.

In the present study, LiFePO4 (LFP) has been synthesized using a flame spray pyrolysis unit followed by carbon coating on LFP using a novel strategy of dehydration assisted polymerization process (DAP) in order to improve its electronic conductivity. Characterization studies revealed the presence of a pure LFP structure and the formation of a thin, uniform and graphitic carbon layer with a thickness of 6–8 nm on the surface of the LFP. A carbon coated LFP with 3 wt% of carbon, using a DAP process, delivered a specific capacity of 167 mA h g−1 at a 0.1C rate, whereas LFP carbon coated by a carbothermal process (CLFP-C) delivered a capacity of 145 mA h g−1 at 0.1C. Further carbon coated LFP by the DAP exhibited a good rate capability and cyclic stability. The enhanced electrochemical performance of C-LFP by DAP is attributed to the presence of a uniform, thin and ordered graphitic carbon layer with a core–shell structure, which greatly increased the electronic conductivity of LFP and thereby showed an improved electro-chemical performance. Interestingly, the developed carbon coating process has been extended to synthesize a bulk quantity (0.5 kg) of carbon coated LFP under optimized experimental conditions as a part of up-scaling and the resulting material electro-chemical performance has been evaluated and compared with commercial electrode materials. Bulk C-LFP showed a capacity of 131 mA h g−1 and 87 mA h g−1 at a rate of 1C and at 10C, respectively, illustrating that the developed DAP process greatly improved the electrochemical performance of LFP in terms of rate capability and cyclic stability, not only during the lab scale synthesis but also during the large scale synthesis. Benchmark studies concluded that the electro-chemical performance of C-LFP by DAP is comparable with that of TODA LFP and better than that of UNTPL LFP. The DAP process developed in the present study can be extended to other electrode materials as well.

Development of visible-light-driven photocatalysts by employing a relatively simple, efficient, and cost-effective one-step process is essential for commercial applications. Herein, we report for the first time the synthesis of in situ Cu-ion modified Ti3+ self-doped rutile TiO2 by such a facile one-step solution precursor plasma spray (SPPS) process using a water-soluble titanium precursor. In the SPPS process, Ti3+ self-doping on Ti4+ of rutile TiO2 is found to take place because of electron transfer from the created oxygen vacancies to Ti4+-ions. In situ Cu modification of the above Ti3+ self-doped rutile TiO2 by additionally introducing a Cu solution into plasma plume is also demonstrated. While the Ti3+ self-doping induces broad absorption in the visible-light region, the addition of Cu ion leads to even broader absorption in the visible region owing to resulting synergistic properties. The above materials were evaluated for various self-cleaning photocatalytic applications under visible-light illumi...

In the present study, we have developed a simple and cost-effective approach for the synthesis of carbon coated LiFePO₄ wherein different carbon precursors were used to find out the suitable precursor for carbon coating. Initially, the appropriate amount of Li, Fe, and P precursors and carbon source (glucose/sucrose/fructose) were dissolved in ethanol solution followed by hydrothermal treatment at 180 °C to obtain carbon coated LiFePO₄. The structure and morphological analysis of

The photocatalytic activity of a hydrogen fluoride (HF)-treated rutile TiO2(001) surface for the decomposition reaction of linoleic acid was lower than that of an as-received (polished) rutile TiO2(001) surface. The surfaces of as-received TiO2(001) and HF-treated TiO2(001) were investigated using low-energy electron diffraction (LEED) and surface X-ray diffraction (SXRD) to elucidate differences in their photocatalytic activities. The as-received (polished) surface did not yield good LEED patterns, which implied that the surface was not well-ordered and was thus not examined using SXRD. In contrast, the HF-treated surface produced good LEED patterns with a 1 × 1 structure and was thus studied using SXRD. The analysis of crystal truncation rods indicated that all atoms in the four layers of the surface moved toward the bulk and that the HF-treated surface was (101)-faceted with terraces. On average, the facet was found to be four layers deep. The difference in the condition of the surface influences the photocatalytic activity of the surface.

Herein, we report the development of a ZnO-based visible-light-driven photocatalyst by interfacial charge transfer process for the inactivation of pathogens under visible-light illumination. Surface modification by a cocatalyst on ZnO, prepared by flame spray pyrolysis process is carried out to induce the visible-light absorption in ZnO. Optical studies showed that surface modification of Cu(2+) induces the visible-light absorption in ZnO by interfacial charge transfer between ZnO and surface Cu(2+) ions upon light irradiation. The photocatalytic efficiency of pure and modified ZnO is evaluated for the inactivation of pathogens and the decomposition of methylene blue under visible-light illumination. The antibacterial activity of Cu(2+)-ZnO is several orders higher than pure ZnO and commercial Degussa-P25 and comparable with Cu(2+)-TiO2. Cu(2+)-ZnO nanorods show better photocatalytic activity than Cu(2+)-ZnO nanosphere, which is attributed to high surface area to volume ratio of former than later. The holes generated in the valence band and the Cu(1+) species generated during the interfacial charge transfer process may attribute for the inactivation of bacteria, whereas the strong oxidation power of hole is responsible for the decomposition of methylene blue. Besides the advantage of Cu(2+)-modified ZnO for visible-light-assisted photocatalytic applications, the method (FSP) used for the synthesis of ZnO in the present study is attractive for commercial application because the process has potential for the production of large quantities (2-3 kg/h) of semiconductors.

The effect of the surface conditions of (001) and (100) rutile TiO2 surfaces on the photocatalytic decomposition of linoleic acid was investigated. The rate of decomposition was observed by measuring the weight of the remaining linoleic acid. The as-received (polished) (001) surface showed a higher photocatalytic activity than the (100) surface, but the activity was greatly reduced when the surface was treated by HF solution and heated to 400°C. Condition of the surface strongly affects the photocatalytic activity. The heated (001) surface partially regained its activity after multiple parallel grooves were introduced along the [110] direction. However, the surface did not regain its activity if these grooves were instead introduced along the [1-10] or [100] directions.

In the present study, LiFePO

In this chapter synthesis of nanomaterials by various nanomanufacturing (top-down and bottom-up) processes, synthesis and properties of aerogel, and advanced electrodeposited coatings and their properties, are reviewed. Further, the potential applications of nanomaterials, aerogels, and electrodeposited coatings in the aerospace industry are concisely surveyed.

Development of visible-light-driven photocatalysts by employing a relatively simple, efficient, and cost-effective one-step process is essential for commercial applications. Herein, we report for the first time the synthesis of in situ Cu-ion modified Ti

In recent years, energy storage devices such as supercapacitors (SC) and Li-ion batteries (LIB) have attracted worldwide interest due to their critical role in replacing the conventional fuels in the transportation sector and also owing to their promising electro-chemical characteristics like long cycle life, high energy density, high power density and low toxicity [1]. In LIBs and SCs, carbon electrode material is arguably an important component and plays a pivotal role in the device performance. However, development of low cost carbon electrode materials with improved energy density and long cycle stability are the great challenges to meet the increasing demands of upcoming electric vehicle technology. Various carbon materials, such as activated carbon, mesoporous carbon, graphene and carbon nanotubes have been extensively studied as electrode materials. However, there are certain limitations using these materials for commercial applications due to their inappropriate pore structure, high cost, tedious synthesis conditions etc. [2]. Graphene-like porous carbon sheets (GPCSs) have recently been viewed as the outstanding electrode materials for high rate electrochemical storage devices such as supercapacitors and Li-ion batteries because the 2D porous carbon sheets can integrate the high conductivity as well as high porosity to promote the facile diffusion of both ion transport and electron transfer. Herein, synthesizing graphene like porous carbon sheets from a renewable biomass waste (Hibiscus cannabinus sticks) is of great importance in lowering the production costs and also promoting environmental protection. The relationship between structure of the GPCS-X (X represents the concentration of activation agent) and its electrochemical performance at different concentration of activating agent is explored in detail. The resulting porous carbon sheets possesses excellent textural parameters with a high specific surface area of 2308 m2/g, highly ordered graphitic carbon with a ID/IG ratio of 0.315 which is confirmed by BET, Raman, HR-TEM (Figure 1a and 1b) etc. While being used as supercapacitor application, the GPCS electrode exhibits a high specific capacitance of 240 F/g at 1A/g, excellent rate capability (84% capacity retention at 50 A/g) and also shows outstanding cyclic stability (92% capacitance retention after 25,000 cycles) in aqueous electrolyte. When tested in organic electrolyte with an extended voltage window, the electrode exhibits symmetric charge-discharge profiles as shown in figure 1c. Also, for Li-ion battery application, GPCS electrode material as shown in figure in 1d displayed a high reversible capacity (1050 mAh/g at 100 mA/g), excellent rate performance (230 mAh/g at 5000 mA/g), and good cycling stability (72% capacitance retention after 400 cycles). The excellent electrochemical performance of GPCS electrode material can be attributed to the high electrical conductivity of the graphene network along with high specific surface area. These results demonstrate a facile, low-cost, eco-friendly design of electrode materials for energy storage applications. Figure 1 (a) FE-SEM and (b) HR-TEM images of GPCS material (c) Charge-Discharge profiles for Supercapacitor application and (d) Rate comparison for Li-ion battery application. References: [1] P.G. Bruce, S. A. Freunberger, L. J. Hardwick, J. M. Tarascon, Nature Materials, 2012, 11, 19-29. [2] K. Nanaji, A. Jyothirmayi, U.V. Varadaraju, T. N. Rao, S. Anandan, Journal of Alloys and Compounds, 2017, 723, 488-497 Figure 1

We develop a simple approach to fabricate graphene-loaded TiO(2) thin films on glass substrates by the spin-coating technique. Our graphene-loaded TiO(2) films were highly conductive and transparent and showed enhanced photocatalytic activities. More significantly, graphene/TiO(2) films displayed superhydrophilicity within a short time even under a white fluorescent light bulb, as compared to a pure TiO(2) film. The enhanced photocatalytic activity of graphene/TiO(2) films is attributed to its efficient charge separation, owing to electrons injection from the conduction band of TiO(2) to graphene. The electroconductivity of the graphene-loaded TiO(2) thin film also contributes to the self-cleaning function by its antifouling effect against particulate contaminants. The present study reveals the ability of graphene as a low cost cocatalyst instead of expensive noble metals (Pt, Pd), and further shows its capability for the application of self-cleaning coatings with transparency. The promising characteristics of (inexpensive, transparent, conductive, superhydrophilic, and highly photocatalytically active) graphene-loaded TiO(2) films may have the potential use in various indoor applications.

Mesoporous C/N doped TiO2 (MCNT) samples were prepared, and Pt was deposited on their surfaces. The hydrogen production capability of this material was investigated by irradiating it with UV light at two different wavelengths. It was found that MCNT could be used to produce hydrogen gas. The highest hydrogen production rate was obtained when 0·003 mol Pt was deposited on the surface of 1 mol MCNT. Since this optimal Pt concentration is the same as that for P-25, it was concluded that the mesopore surface was not directly deposited with Pt. More hydrogen was produced when Pt deposited MCNT was irradiated with 350 nm wavelength UV light than with 370 nm wavelength UV light at similar intensity. This implies that the wavelength of UV light strongly affects hydrogen production.

Mesoporous C-N doped TiO2 (MCNT) was prepared and Pt was deposited on the surface. Hydrogen production capability of the material with UV light, visible light, and sunlight was studied. The zeta potential was measured before and after hydrogen production. It was found that MCNT could be used to produce hydrogen gas. The highest hydrogen production was reached when MCNT prepared at 500 °C was irradiated with sun light. Zeta potential after UV and sun light irradiation tends to increase compared to before the irradiation. When the zeta potential showed negative value which indicates the presence of thin diffuse double layer, large amount of hydrogen was generated. However, when dispersed particles after irradiation of UV or sun light showed larger zeta potential, small amount of hydrogen was produced. This suggests that thick diffuse double layer formed on the surface of TiO2 particles may decrease the wettability between solution and particles.

Supercapacitors (SCs), which have been extensively applied in consumer electronics and energy management, are alternative energy storage devices for their high power densities. Electrochemical double layer capacitors (EDLCs) storing charge on the interface between electrode and electrolyte and pseudocapacitors associated with rapid surface redox reaction are the two categories of SCs. The former requires carbon materials with high specific surface area, high conductivity and suitable pore channels to achieve promising specific capacitance and long cycling life. N-doped activated carbon has been synthesized using cork, a biomass waste obtained from the bark of oak trees as carbon source by a two step thermal annealing process. The obtained carbon material possesses honey comb structure with microporous structure, high specific surface area (up to 1172 m2 /g) and large pore volume (0.12 cm3/g). Besides, N-doped carbon (CAC 1:1) with a nitrogen content of 5.17 wt.% exhibits a maximum specific capacitance of 185 F/g at a current density of 1 A/g in 6 M KOH aqueous electrolyte. It also displays a good rate performance, i.e., 176 F/g at 10 A/g and cycle stability, i.e., ~80.3% retention after 1175 charge-discharge cycles. The assembled CAC1:1 symmetric capacitor exhibits a maximum energy density of 20.2 Wh/kg at a power density of 448 W/kg within a voltage range of 0 - 1.8 V in 1M Na2SO4 aqueous electrolyte. The unique porous structure and N-doping characteristic endue the electrode material a potential candidate for high-performance supercapacitors.

In the recent years, the intercalation based lithium-ion batteries (LIBs) are considered as the potential candidate for portable electronic devices. However, development of low cost electrode materials with improved energy density and long cycle stability are the great challenges to meet the increasing demands of upcoming electric vehicle technology [1]. Among the rechargeable LIB electrode materials, sulfur cathode offers high theoretical specific capacity of 1672 mAh g-1 (energy density of 2600 Wh kg-1), which is ~ 3-5 times higher than the conventionally used LIB cathode materials. Moreover, the elemental sulfur is abundantly available in nature, eco-friendly and hence the fabricated cells using sulfur cathode is expected to deliver high electrochemical performance with low cost. However, the commercialization of this system is hampered largely owing to low electrical conductivity of elemental sulfur, polysulfide dissolution into the electrolyte and large volume expansion during charge/discharge process resulted in poor electrochemical performance of the cell [2,3]. To mitigate these issues, various strategies including designing of unique cathode structure comprising of carbon based materials (micro & mesoporous carbons, MWCNTs, graphene and graphene oxide), metal oxide composites, conductive polymers, etc have been tried so far. Particularly carbon materials are of interest, because micro and mesoporous carbon materials are known for efficient trapping of dissolved polysulfides during redox process to enhance the performance of lithium-sulfur (Li-S) battery [2]. In the present study, we synthesized a biomass derived high surface area activated carbon (AC) with narrow pore size distribution and high graphitic content and used it as host for sulfur cathode in Li-S battery. FE-SEM and HR-TEM images (Figure 1a and 1b) of as prepared AC reveals the presence of carbon with graphene sheet like structure (inset of Figure 1a and 1b). The elemental mapping of sulfur infused AC confirms homogenous distribution of elemental sulfur throughout the carbon matrix indicating uniform dispersion after melt diffusion process (155 ºC). The schematic representation of Li-S cell with modified separator is shown in Figure 1c. The use of modified separator is expected to inhibit the migration of dissolved polysulfide into electrolyte solution to the anode surface during redox process. The AC/S composite with modified separator displays impressive electrochemical performance in terms of specific capacity, rate capability and cyclic stability due to efficient trapping of polysulfide species and improved ionic and electronic conductivities. Figure 1d shows the long term cycle performance curve measured at 1 C rate with in-set of CV profile for the initial 10 cycles. The detailed physico-chemical and electrochemical measurements will be discussed during the presentation. Figure 1 (a) FE-SEM and (b) TEM images of as prepared AC sample, (c) schematic representation of Li-S cell with modified separator and (d) Electrochemical cyclic stability data’s of AC/S cathode (in-set CV curve) measured in the voltage range of 1.5-2.8 V at current rate of 1C with pristine separator and modified separator. References: [1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J. M. Tarascon, Nature Materials, 11 (2012) 19-29. [2] H. Sohn, M. L. Gordin, T. Xu, S. Chen, A. Manivannan, D. Wang, ACS Appl. Mater. Interfaces, 6 (2014) 7596-7606. [3] E. Hari Mohan, B. V. Sarada, R. V. R. Naidu, G. Salian, A. K. Haridas, B. V. Appa Rao, T. N.Rao, Electrochimica Acta, 219 (2016) 701-710. Figure 1

Novel flower like microporous carbons with very high surface area have been synthesized for the first time using MCM-22 zeolite as a template and sucrose as a carbon source. The textural parameters of the materials can easily be tuned by the simple adjustment of the sucrose to MCM-22 weight ratio. It has been also found that the specific surface area of the microporous carbon materials is much higher as compared with that of its parent zeolite template.

Model reuse is typically facilitated by search and retrieval tools, matching the sought model with models in the case base or database. This paper looks at providing assistance to users authoring design exemplars, a new data structure to represent parametric and geometric design problems, by providing alternative configurations. Four distinct similarity metrics are proposed for model retrieval in an interactive modeling environment: entity similarity, relationship similarity, attribute similarity, and structural similarity. A brief review of graph matching literature has been provided, followed by a technical session showing the application of a set of derived similarity metrics.

Here, we report facile fabrication of Fe3O4-reduced graphene oxide (Fe3O4-RGO) composite by a novel approach, i.e., microwave assisted combustion synthesis of porous Fe3O4 particles followed by decoration of Fe3O4 by RGO. The characterization studies of Fe3O4-RGO composite demonstrate formation of face centered cubic hexagonal crystalline Fe3O4, and homogeneous grafting of Fe3O4 particles by RGO. The nitrogen adsorption-desorption isotherm shows presence of a porous structure with a surface area and a pore volume of 81.67 m(2) g(-1), and 0.106 cm(3) g(-1) respectively. Raman spectroscopic studies of Fe3O4-RGO composite confirm the existence of graphitic carbon. Electrochemical studies reveal that the composite exhibits high reversible Li-ion storage capacity with enhanced cycle life and high coulombic efficiency. The Fe3O4-RGO composite showed a reversible capacity ∼612, 543, and ∼446 mA h g(-1) at current rates of 1 C, 3 C and 5 C, respectively, with a coulombic efficiency of 98% after 50 cycles, which is higher than graphite, and Fe3O4-carbon composite. The cyclic voltammetry experiment reveals the irreversible and reversible Li-ion storage in Fe3O4-RGO composite during the starting and subsequent cycles. The results emphasize the importance of our strategy which exhibited promising electrochemical performance in terms of high capacity retention and good cycling stability. The synergistic properties, (i) improved ionic diffusion by porous Fe3O4 particles with a high surface area and pore volume, and (ii) increased electronic conductivity by RGO grafting attributed to the excellent electrochemical performance of Fe3O4, which make this material attractive to use as anode materials for lithium ion storage.

Li-ion batteries (LIBs) have become an integral part of most electronic gadgets, automobiles and (large-scale) grid-power devices due to its intriguing properties such as high energy and power density, no memory effect and excellent cyclic stability. After conquering mobile devices, currently LIBs are under the scanner to gain wide-scale use in commercial (plug-in) hybrid electric vehicles (EVs). These EVs based on LIBs are projected as alternative transport system vis-à-vis the conventional gasoline-based automobiles. However short driving range, slow recharge rate and high cost are the major obstacles and limit their extended use in EVs. Hence, demonstration of large scale LIBs for EV is far more challenging owing to the complex demand of energy density (to deliver 100-200 km per charge) as well as operational safety at viable cost. State-of-the-art lithium-ion cells use layered transition metal oxides, or phosphates or Mn based spinel as cathode and graphitic carbon as anode. Among these, LiFePO4 (LFP) has received much attention as a promising cathode material for high-power lithium-ion batteries used in EVs owing to its abundance, low manufacturing cost, thermal stability, safety, and high theoretical specific capacity. However, low ionic (~ 10-11 to 10-13 cm2 S-1) and intrinsic electronic conductivity (< 10-9 S cm-2) hinder its electro-chemical performance at high rate. Various efforts including (a) doping with supervalent cation, (b) reducing the particle size, and (c) carbon coating have been attempted to overcome these intrinsic defects. Among these efforts, carbon coating has become a widely used solution as it improves the conductivity, prevents metal ion dissolution, avoids direct contact of electrolyte with active material and restricts the crystal growth of electrode material during carbonization process. Though carbon coating is investigated by various methods, most of these methods are struggled by tedious synthesis conditions, non uniform distribution and lack of ordered carbon, which drastically decrease the performance of electrode materials. More importantly, a suitable carbon coating technique which provides collective characteristics of carbon such as (a) low carbon content, (b) thin layer carbon coating, (c) formation of graphitic carbon (d) homogeneous distribution of carbon coating and (e) core-shell structured of carbon coated electrode is yet to be realized. With this point in mind, a simple, unique and cost effective carbon coating technique to improve the electronic conductivity of electrodes has been discovered. In the present study, we focus on developing carbon coating of lab and large scale (Fig.1A) by dehydration assisted polymerization process, in which usage of dehydrating agent is considered important to form uniform carbon network on LFP. Carbon coating without dehydration agent is also carried out for comparison. The resulting carbon coated electrode material was extensively characterized by various characterization techniques. Structural studies revealed that carbon coating did not alter the crystal structure of LFP and HR-TEM analysis shows the formation of core-shell structure (Fig.1B), i.e., formation of thin layer of carbon (6-8 nm) with less carbon content (3 wt.%) on LiFePO4 particles; ideal for fast lithium ion diffusion during charge/discharge process. The developed carbon coating process led to the formation of sp2 hybridized carbon rich layer by proper catenation of carbon in the presence of dehydration agent, indicating the dominance of graphitic carbon in carbon coated LFP (C-LFP). Characterization studies of carbon coated LFP without dehydrating agent showed that the process was not eminent in yielding required carbon characteristics. The electro-chemical performance of C-LFP was evaluated in half/full cell configuration and benchmark with commercial electrode materials. C-LFP using dehydrating agent exhibit capacity of ~ 85 mA h g-1 at 5C rate with excellent cyclic stability and rate capability, whereas C-LFP without dehydrating agent exhibit a capacity of ~ 43 mA h g-1 at 5 C rate. The specific capacity of C-LFP is 131 mA h g-1 at 1C, whereas the specific capacity of commercially available C-LFP, i.e., UNTPL and TODA is 87 and 143 mA h g-1 respectively (Fig.1C & 1D), demonstrating that developed C-LFP in the present study showing better electro-chemical performance than C-LFP (conventional & UNTPL) and on par with C-LFP (TODA). The excellent electro-chemical performances of C-LFP developed in the present study is attributed to the presence of uniform, thin layer, core-shell structure and high graphitic nature of carbon in carbon coated LFP. Full cell studies of C-LFP with lithium titanate as counter electrode was also carried out and the results are promising. The novel, simple and cost-effective carbon coating process developed in the present study is of potential interest to other low conductive cathode materials and to develop high-power LIBs for EVs application. Figure 1

Four crop residue based complete diets (60R: 40C) with Andhra hybrid and Telangana sorghum stover, paddy straw and sweet sorghum bagasse with leaf residue (SSBLR) as sole roughage were formulated and processed into either mash or block form to study the effect of crop residue, cultivar and physical form on intake, nutrient utilization and N balance in growing Deccani ram lambs through metabolism trial. Fifty six Deccani ram lambs were randomly divided into eight groups of seven each and offered either block or mash form of the four crop residue based diets for a period of 25 d. DMI (g/d, g/kg BW or g/kg W0.75) of complete diet was not influenced by the type of crop residue or cultivar. Physical form of the diet had significant influence on DMI being higher (20–29%) in lambs fed mash than block diets irrespective of crop residue and cultivar. Digestibility of DM, OM, CP and cell wall constituents (NDF and ADF) was influenced by the type of crop residue and cultivar but physical form (mash vs. block) of the diet had no significant effect on nutrient digestibility except CP. Intake of OM, DOM, CP (g/d) and ME (MJ/d) was significantly higher in sheep fed mash form of diets than block form irrespective of cultivar and crop residue in the diet. Type of crop residue has no influence on nutrient intake except DOMI but cultivar in the complete diet had influence on nutrient intake either significantly (DOM, CP; P

Amorphous Cu(II) nanoclusters grafted WO(3) particles were coated on a smooth TiO(2) film, and site selective depositions of PbO(2) and metal Ag particles by photocatalytic processes were observed on TiO(2) and WO(3) due to transfer of holes to TiO(2), and accumulation of electrons in WO(3) respectively. As a result, the photocatalytic activity of TiO(2) modified Cu(II)-WO(3) increased ~3.5 fold higher than that of Cu(II)-WO(3).