Improved electrochemical performances of binder-free CoMoO₄ nanoplate arrays@Ni foam electrode using redox additive electrolyte

Veerasubramani, G.K.,Krishnamoorthy, K.,Kim, S.J. Elsevier Sequoia 2016 Journal of Power Sources Vol.306 No.-

Herein, we are successfully prepared cobalt molybdate (CoMoO<SUB>4</SUB>) grown on nickel foam as a binder free electrode by hydrothermal approach for supercapacitors and improved their electrochemical performances using potassium ferricyanide (K<SUB>3</SUB>Fe(CN)<SUB>6</SUB>) as redox additive. The formation of CoMoO<SUB>4</SUB> on Ni foam with high crystallinity is confirmed using XRD, Raman, and XPS measurements. The nanoplate arrays (NPAs) of CoMoO<SUB>4</SUB> are uniformly grown on Ni foam which is confirmed by FE-SEM analysis. The prepared binder-free CoMoO<SUB>4</SUB> NPAs achieved maximum areal capacity of 227 μAh cm<SUP>-2</SUP> with KOH electrolyte at 2.5 mA cm<SUP>-2</SUP>. This achieved areal capacity is further improved about three times using the addition of K<SUB>3</SUB>Fe(CN)<SUB>6</SUB> as redox additive. The increased electrochemical performances of CoMoO<SUB>4</SUB> NPAs on Ni foam electrode via redox additive are discussed in detail and the mechanism has been explored. Moreover, the assembled CoMoO<SUB>4</SUB> NPAs on Ni foam//activated carbon asymmetric supercapacitor device with an extended operating voltage window of 1.5 V exhibits an excellent performances such as high energy density and cyclic stability. The overall performances of binder-free CoMoO<SUB>4</SUB> NPAs on Ni foam with redox additives suggesting their potential use as positive electrode material for high performance supercapacitors.

Impact of Environmental Factors and Altitude on Growth and Reproductive Characteristics of Teak (Tectona grandis Linn. f.) in Southern India

Krishnamoorthy, M.,Palanisamy, K.,Francis, A.P.,Gireesan, K. Institute of Forest Science 2016 Journal of Forest Science Vol.32 No.4

The effect of different environmental conditions and altitudes on the growth and reproductive characteristics in 12 teak plantations at 4 different blocks (Cauvery canal bank, Topslip and Parambikulam (Tamil Nadu), Nilambur and Wayanad (Kerala) of Southern India was investigated. The annual rainfall and mean monthly temperature of the study areas varied significantly from 1390 to 3188 mm and 16 to $38^{\circ}C$ respectively. The teak plantations in Cauvery canal bank which grow in continuous moisture condition (8-10 months) retain the leaf for longer period due to moisture resulting continuous supply of photosynthates leads to fast and outstanding growth. The girth at breast height (GBH) of 34-years-old tree in canal area was similar to that of 40 to 49-years-old trees in other locations, indicating that teak plantations with regular watering and silvicultural practices may be harvested at the age of 30 years. The leaf fall, flowering and fruiting showed significant variations in different teak plantations due to environmental factors and altitudes. It was found that increase of rainfall enhances number of flowers in the inflorescence in teak. Tholpatty (block-IV) showed more flowering in a inflorescence (3,734-3,744) compared to other plantations (1,678-3,307). Flowering in Nilambur and Wayanad coincided with heavy rainfall resulting low fruitset (1.1-2.3%) probably heavy rainfall ensuing restriction of pollinators for effective pollination. On the other hand, flowering in Cauvery canal bank (Block-I) was not coincided with high rainfall exhibited high fruitset (2-3%). About 66 to 76% of the fruits in different plantations were empty, and it is one of the main reasons for poor germination in teak. The seeds of Topslip and Parambikulam (Block-II) showed higher seed weight, maximum seed filling and good germination indicating that the environmental factors and altitude play significant role in fruit setting and seed filling in teak. In addition, the teak plantations in Topslip and Parambikulam showed good growth suggesting that plantations in the altitude range of approximately 550-700 m may be suitable for converting into seed production areas for production of quality seeds.

Changes of arbuscular mycorrhizal traits and community structure with respect to soil salinity in a coastal reclamation land

Krishnamoorthy, R.,Kim, K.,Kim, C.,Sa, T. Elsevier Science B.V., Amsterdam. 2014 Soil biology & biochemistry Vol.72 No.-

A comprehensive knowledge on the relationship between soil salinity and arbuscular mycorrhizal fungi (AMF) is vital for a deeper understanding of ecosystem functioning under salt stress conditions. The objective of this study was to determine the effects of soil salinity on AMF root colonization, spore count, glomalin related soil protein (GRSP) and community structure in Saemangeum reclaimed land, South Korea. Soil samples were collected and grouped into five distinct salt classes based on the electrical conductivity of soil saturation extracts (ECse). Mycorrhizal root colonization, spore count and GASP were measured under different salinity levels. AMF community structure was studied through three complementary methods; spore morphology, terminal restriction fragment length polymorphism (T-RFLP) and denaturing gradient gel electrophoresis (DGGE). Results revealed that root colonization (P < 0.01), spore count (P < 0.01) and GRSP (P < 0.01) were affected negatively by soil salinity. Spore morphology and T-RFLP data showed predominance of AMF genus Glomus in Saemangeum reclaimed land. T-RFLP and DGGE analysis revealed significant changes in diversity indices between non (ECse < 2 dS/m) and extremely (ECse > 16 dS/m) saline soil and confirmed dominance of Glomus caledonium only in soils with ECse < 8 dS/m. However, ribotypes of Glomus mosseae and Glomus proliferum were ubiquitous in all salt classes. Combining spore morphology, T-RFLP and DGGE analysis, we could show a pronounced effect in AMF community across salt classes. The result of this study improve our understanding on AMF activity and dominant species present in different salt classes and will substantially expand our knowledge on AMF diversity in reclaimed lands. (C) 2014 Elsevier Ltd. All rights reserved.

Designing two dimensional nanoarchitectured MoS₂ sheets grown on Mo foil as a binder free electrode for supercapacitors

Krishnamoorthy, K.,Veerasubramani, G.K.,Pazhamalai, P.,Kim, S.J. Pergamon Press 2016 ELECTROCHIMICA ACTA Vol.190 No.-

In this study, we demonstrated the preparation of nanoarchitectured MoS<SUB>2</SUB> sheets grown on Mo foil via hydrothermal method and examined its use as a binder free electrode for supercapacitors. The formation of well crystalline MoS<SUB>2</SUB> sheets on Mo foil was confirmed by laser Raman spectroscopy, Raman mapping, X-ray photoelectron spectroscopy, and field emission scanning electron microscopic analyses. The cyclic voltammetric studies suggested that the charge-storage mechanism in the MoS<SUB>2</SUB>/Mo electrodes is due to the contribution of combined pseudocapacitance with electrochemical double layer capacitance. The MoS<SUB>2</SUB>/Mo electrodes delivered a specific capacitance of about 192.7F/g from the galvanostatic charge-discharge analysis at a current density of 1mA/cm<SUP>2</SUP>. The experimental results suggested that the prepared MoS<SUB>2</SUB>/Mo binder free electrode will be a suitable candidate for electrochemical energy storage devices.

Graphene oxide nanopaint

Krishnamoorthy, K.,Jeyasubramanian, K.,Premanathan, M.,Subbiah, G.,Shin, H.S.,Kim, S.J. Pergamon Press ; Elsevier Science Ltd 2014 Carbon Vol.72 No.-

Nanostructured materials are receiving growing interest in the development of a number of commercial products. In this study, we have developed a multifunctional graphene oxide (GO) nanopaint by incorporating GO sheets in an alkyd resin with suitable non-toxic additives using ball milling. The drying mechanism of the GO nanopaint has been discussed. Intermolecular cross-linking between GO and the lipid chains in the alkyd resin was studied by Fourier transform infra red spectra, Raman spectra, and X-ray photoelectron spectra, respectively. The prepared GO nanopaint exhibited good corrosion-resistant behavior in both acidic and high-salt-content solutions as examined by the immersion and electrochemical corrosion tests. The GO nanopaint coating possesses a corrosion protection efficiency of about 76% in salt water as estimated from the linear polarization studies. The antibacterial property of the GO nanopaint coated surface was studied against three bacterial strains (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) and the results showed that GO nanopaint inhibited the bacterial growth on its surface. The in situ biofouling tests demonstrated the inhibition of fouling on the GO nanopaint surface.

Graphdiyne nanostructures as a new electrode material for electrochemical supercapacitors

Krishnamoorthy, K.,Thangavel, S.,Chelora Veetil, J.,Raju, N.,Venugopal, G.,Kim, S.J. Pergamon Press ; Elsevier Science Ltd 2016 International journal of hydrogen energy Vol.41 No.3

<P>The utility of carbon materials for electrochemical energy storage devices has been rapidly increasing in the recent years. In this study, graphdiyne nanostructures have been prepared via a cross-coupling reaction and their electrochemical properties were investigated for supercapacitor applications. Spectroscopic studies such as X-ray photoelectron spectroscopy and Raman analysis confirmed the formation of graphdiyne with high order and low defects. Cyclic voltammetric studies revealed the quasi-rectangular profiles suggesting the presence of electrochemical double layer and Faradaic capacitance in graphdiyne. The graphdiyne electrode delivered a specific capacitance of about 71.4 F/g from the galvanostatic charge discharge analysis measured at a constant discharge current density of 3.5 A/g. Moreover, the cyclic stability tests demonstrated excellent capacitance retention of about 97% for the graphdiyne electrode. These studies suggested the potential applications of graphdiyne as an electrode material for supercapacitor devices. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.</P>

Arbuscular mycorrhizal fungi and associated bacteria isolated from salt-affected soil enhances the tolerance of maize to salinity in coastal reclamation soil

Krishnamoorthy, R.,Kim, K.,Subramanian, P.,Senthilkumar, M.,Anandham, R.,Sa, T. Elsevier 2016 Agriculture, ecosystems & environment Vol.231 No.-

Arbuscular mycorrhizal fungi (AMF) have close association with bacteria in establishing a tripartite interaction with plants. The objective of this study was to assess the tripartite interactions among AMF, associated bacteria and maize on enhancing salt stress tolerance. AMF spores isolated from coastal reclamation land were identified as Rhizophagus intraradices and multiplied using monosporic mass culturing. From surface-decontaminated spores of R. intraradices, isolation of associated bacteria was carried out and the obtained isolate was identified as Massilia sp. RK4. The isolated bacterial strain was found to possess several plant growth promoting characteristics and for further studies, its effect on maize plant growth in coastal reclamation soil was evaluated under three different salt concentrations. Salt stress substantially reduced plant growth, root colonization and spore-producing ability of the R. intraradices. However, treatment with the AMF and a combination of AMF and associated bacteria alleviated the salt-induced reduction of plant growth, root colonization, nutrient accumulation and lowered leaf proline levels compared to control treatment. The co-inoculation of R. intraradices and Massilia sp. RK4 exhibited significant impact on AMF root colonization and nutrient accumulation in plants compared to inoculation with R. intraradices only. Inoculation of R. intraradices and Massilia sp. RK4 improved the salinity tolerance of maize through the dual effect exerted by AMF and its associated bacteria.

Impact of Environmental Factors and Altitude on Growth and Reproductive Characteristics of Teak (Tectona grandis Linn. f.) in Southern India

M. Krishnamoorthy,K. Palanisamy,A.P. Francis,K. Gireesan 강원대학교 산림과학연구소 2016 Journal of Forest Science Vol.32 No.4

The effect of different environmental conditions and altitudes on the growth and reproductive characteristics in 12 teak plantations at 4 different blocks (Cauvery canal bank, Topslip and Parambikulam (Tamil Nadu), Nilambur and Wayanad (Kerala) of Southern India was investigated. The annual rainfall and mean monthly temperature of the study areas varied significantly from 1390 to 3188 mm and 16 to 38oC respectively. The teak plantations in Cauvery canal bank which grow in continuous moisture condition (8-10 months) retain the leaf for longer period due to moisture resulting continuous supply of photosynthates leads to fast and outstanding growth. The girth at breast height (GBH) of 34-years-old tree in canal area was similar to that of 40 to 49-years-old trees in other locations, indicating that teak plantations with regular watering and silvicultural practices may be harvested at the age of 30 years. The leaf fall, flowering and fruiting showed significant variations in different teak plantations due to environmental factors and altitudes. It was found that increase of rainfall enhances number of flowers in the inflorescence in teak. Tholpatty (block-IV) showed more flowering in a inflorescence (3,734-3,744) compared to other plantations (1,678-3,307). Flowering in Nilambur and Wayanad coincided with heavy rainfall resulting low fruitset (1.1-2.3%) probably heavy rainfall ensuing restriction of pollinators for effective pollination. On the other hand, flowering in Cauvery canal bank (Block-I) was not coincided with high rainfall exhibited high fruitset (2-3%). About 66 to 76% of the fruits in different plantations were empty, and it is one of the main reasons for poor germination in teak. The seeds of Topslip and Parambikulam (Block-II) showed higher seed weight, maximum seed filling and good germination indicating that the environmental factors and altitude play significant role in fruit setting and seed filling in teak. In addition, the teak plantations in Topslip and Parambikulam showed good growth suggesting that plantations in the altitude range of approximately 550-700 m may be suitable for converting into seed production areas for production of quality seeds.

Designing ZnS decorated reduced graphene-oxide nanohybrid via microwave route and their application in photocatalysis

Thangavel, S.,Krishnamoorthy, K.,Kim, S.J.,Venugopal, G. Elsevier Sequoia 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.683 No.-

In this study, we demonstrated the facile design of zinc-sulphide decorated reduced graphene-oxide (ZnS-rGO) nanohybrid via microwave method and examined their photocatalytic properties. The physico-chemical properties of the ZnS-rGO were analysed using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, high resolution scanning electron microscopy, energy dispersive X-ray spectroscopy and laser Raman analyses, respectively. The photocatalytic activity of the prepared ZnS-rGO nanohybrid was examined by the degradation of two model dyes Methylene blue (MB) and Rhodamine-B (RhB). The experimental results suggested that the designed ZnS-rGO nanohybrid possess superior photocatalytic activity with 1.47 and 2.92 fold higher reaction rates for MB and RhB degradation than that of the pure ZnS nanoparticles. A plausible mechanism for the enhanced properties of ZnS-rGO nanohybrid was discussed using photoluminescence spectra. Further, the role of reactive oxygen species on the photocatalytic properties of ZnS-rGO nanohybrid was investigated using appropriate electron and hole scavengers.

Investigation on Flashover Development Mechanism of Polymeric Insulators by Time Frequency Analysis

C. Muniraj,K.Krishnamoorthi,S.Chandrasekar 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.6

This paper deals with the analysis of leakage current characteristics of silicone rubber insulator in order to develop a new condition monitoring tool to identify the flashover of outdoor insulators. In this work, laboratory based pollution performance tests are carried out on silicone rubber insulator under ac voltage at different pollution levels and relative humidity conditions with sodium chloride (NaCl) as a contaminant. Min-Norm spectral analysis is adopted to calculate the higher order harmonics and Signal Noise Ratio (SNR). Choi-Williams Distribution (CWD) function is employed to understand the time frequency characteristics of the leakage current signal. Reported results on silicone rubber insulators show that the flashover development process of outdoor polymer insulators could be identified from the higher order harmonics and signal noise ratio values of leakage current signals.