Rose-like MoS₂ nanostructures with a large interlayer spacing of ∼9.9 Å and exfoliated WS₂ nanosheets supported on carbon nanotubes for hydrogen evolution reaction

Thangasamy, Pitchai,Oh, Saewoong,Nam, Sanghee,Oh, Il-Kwon Elsevier 2020 Carbon Vol.158 No.-

<P><B>Abstract</B></P> <P>In this study, we report a rose-like MoS<SUB>2</SUB> and <I>in-situ</I> exfoliated WS<SUB>2</SUB> nanoarchitecture supported on carbon nanotube networks for enhanced hydrogen evolution reaction. The interlayer expansion of MoS<SUB>2</SUB> was carried out during <I>in-situ</I> exfoliation of WS<SUB>2</SUB> nanosheets under a solvothermal process based on the ethanol-water mixture of sodium molybdate dihydrate and organosulfur chelating agent. Then, the MoS<SUB>2</SUB>-WS<SUB>2</SUB> nanostructures are attached with carbon nanotubes (CNTs) to obtain the MoS<SUB>2</SUB>-WS<SUB>2</SUB>-CNTs nanoarchitectures where the interlayer expanded rose-like MoS<SUB>2</SUB> nanostructures and the delaminated WS<SUB>2</SUB> nanosheets are strongly associated with the electrically conductive carbon nanotubes, leading to a strong synergistic interaction among MoS<SUB>2</SUB>, WS<SUB>2</SUB>, and CNTs. Hence, the fabricated MoS<SUB>2</SUB>-WS<SUB>2</SUB>-CNTs nanoarchitectures delivered superior electrocatalytic activity towards the hydrogen evolution reaction (HER), yielding a current density of 10 mA cm<SUP>−2</SUP> at a low overpotential of ∼212 mV with a Tafel slope of 50 mV dec<SUP>−1</SUP>. Such superior HER electrocatalytic activity is due to the existence of abundant catalytic active sites in the both rose-like MoS<SUB>2</SUB> nanostructures with large interlayer spacing of ∼9.9 Å and exfoliated WS<SUB>2</SUB> nanosheets with more edge sites, and facile electron transfer between conductive substrate and electrocatalytically active MoS<SUB>2</SUB>/WS<SUB>2</SUB> materials through CNTs conducting channel.</P> <P><B>Graphical abstract</B></P> <P>A one-step solvothermal method was demonstrated for the simultaneous synthesis of interlayer expanded MoS<SUB>2</SUB> nano-rose and few layer WS<SUB>2</SUB> nanosheets with uniform CNTs distribution for electrochemical hydrogen evolution reaction.</P> <P>[DISPLAY OMISSION]</P>

A Copper(II) complex of a new hydrazone: A solid-state single source precursor for the preparation of both Cu and CuO nanoparticles

Selvam, Pitchai,Sathiyakumar, Subramani,Srinivasan, Krishnan,Premkumar, Thathan Elsevier 2019 Journal of molecular structure Vol.1177 No.-

<P><B>Abstract</B></P> <P>A novel hydrazone, ethyl 4-(pyridine-4yl-methylene) hydrazinecarboxylate (C<SUB>9</SUB>H<SUB>11</SUB>N<SUB>3</SUB>O<SUB>2</SUB>; 4-py), and Cu(II) complex [Cu(4-py)<SUB>2</SUB>(CH<SUB>3</SUB>COO)<SUB>2</SUB>(H<SUB>2</SUB>O)] (<B>1</B>) were synthesized and characterized via elemental analysis, FT-IR, <SUP>1</SUP>H NMR and <SUP>13</SUP>C NMR spectral techniques. The structure of <B>1</B> was determined through single crystal X-ray diffraction. The structure consists of monomers in which copper is penta-coordinated through a distorted square pyramidal geometry. The pyridine nitrogen atoms of two monodentate 4-py ligands and oxygen atoms from two monodentate acetate anions form the basal plane. The apical site is occupied by a water molecule. Nano sized copper metal (∼5 nm) and copper oxide (∼10 nm) were separately prepared via thermal decomposition of the as-prepared copper complex by varying the atmospheric conditions under which the complex was calcined at 400 °C for 1 h. Powder x-ray diffraction (PXRD) patterns confirmed that the prepared Cu and CuO nanoparticles were of high purity and crystallinity. Hence, this complex could be used as a single solid-state precursor to prepare both Cu and CuO nanoparticles via low temperature decomposition under different atmospheric conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We prepared a [Cu(4-py)<SUB>2</SUB>(CH<SUB>3</SUB>COO)<SUB>2</SUB>(H<SUB>2</SUB>O)] complex from a new hydrazine. </LI> <LI> Cu is penta-coordinated with a distorted square pyramidal geometry. </LI> <LI> Nano Cu and CuO can be synthesized by using this complex. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Isolation and characterization of plant growth promoting endophytic bacterial isolates from root nodule of Lespedeza sp.

Palaniappan, Pitchai,Chauhan, Puneet Singh,Saravanan, Venkatakrishnan Sivaraj,Anandham, Rangasamy,Sa, Tongmin Springer-Verlag 2010 BIOLOGY AND FERTILITY OF SOILS - Vol.46 No.8

Realizing High-Performance Li-Polysulfide Full Cells by using a Lithium Bis(trifluoromethanesulfonyl)imide Salt Electrolyte for Stable Cyclability

Ahad, Syed Abdul,Pitchai, Ragupathy,Beyene, Anteneh Marelign,Joo, Sang Hoon,Kim, Do Kyung,Lee, Hyun-Wook Wiley (John WileySons) 2018 CHEM SUS CHEM Vol.11 No.19

Characterization of Plant-Growth Promoting Diazotrophic Bacteria Isolated from Field Grown Chinese Cabbage under Different Fertilization Conditions

임우종,Selvaraj Poonguzhali,마드하이안,Pitchai Palaniappan,M. A. Siddikee,사동민 한국미생물학회 2009 The journal of microbiology Vol.47 No.2

Diazotrophic bacteria isolated from the rhizosphere of Chinese cabbage were assessed for other plant growth promoting characteristics viz., production of IAA, ethylene, ACC deaminase, phosphate solubilization, and gnotobiotic root elongation. Their effect on inoculation to Chinese cabbage was also observed under growth chamber conditions. A total of 19 strains that showed higher nitrogenase activity identified by 16S rRNA gene sequence analysis were found to be the members of the genera Pseudomonas and Agrobacterium belonging to α- and γ-Proteobacteria groups. These strains were also efficient in producing IAA and ACC deaminase though they produced low levels of ethylene and no phosphate solubilization. In addition, inoculation of selected diazotrophic bacterial strains significantly increased seedling length, dry weight, and total nitrogen when compared to uninoculated control. The colonization of crop plants by diazotrophic bacteria can be affected by many biotic and abiotic factors, and further studies are oriented towards investigating the factors that could influence the establishment of a selected bacterial community.

Effect of Rosiglitazone in Sodium Arsenite-induced Experimental Vascular Endothelial Dysfunction

Tajpreet Kaur,Rajesh Kumar Goel,Pitchai Balakumar 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.4

The present study has been designed to investigate the effect of rosiglitazone, a peroxisome proliferator activated receptor γ agonist in sodium arsenite-induced vascular endothelial dysfunction (VED) in rats. The rats were administered sodium arsenite (1.5 mg/kg/day, i.p., 2 weeks) to induce VED. The development of VED was assessed by employing isolated aortic ring preparation and estimating serum nitrite/nitrate concentration. Further,the integrity of the aortic endothelium was assessed histologically using haematoxylin-eosin staining. Moreover, the oxidative stress was assessed by estimating serum thiobarbituric acid reactive substances, aortic reactive oxygen species and reduced form of glutathione. The administration of sodium arsenite produced VED by impairing acetylcholine-induced endothelium dependent relaxation, diminishing the integrity of vascular endothelium and decreasing the serum nitrite/nitrate concentration. In addition, sodium arsenite was noted to produce oxidative stress as it increased serum thiobarbituric acid reactive substances and aortic reactive oxygen species and consequently decreased glutathione. Treatment with rosiglitazone (3 mg/kg/day, p.o., 2 weeks and 5 mg/kg/day, p.o., 2 weeks) significantly prevented sodium arsenite-induced VED by enhancing acetylcholine-induced endothelium dependent relaxation, improving the integrity of vascular endothelium, increasing the nitrite/nitrate concentration and decreasing the oxidative stress. However, the vascular protective effect of rosiglitazone was markedly abolished by co-administration of nitric oxide synthase inhibitor, N-Omega-Nitro-L-Arginine Methyl Ester (L-NAME) (25 mg/kg/day, i.p., 2 weeks). Thus, it may be concluded that rosiglitazone reduces oxidative stress, activates eNOS and enhances the generation of nitric oxide to prevent sodium arsenite-induced VED in rats.

IP Multimedia Subsystem—An Intrusion Detection System

Bakkiam David Deebak,Rajappa Muthaiah,Karuppusamy Thenmozhi,Pitchai Iyer Swaminathan 한국산학기술학회 2013 SmartCR Vol.3 No.1

The IP Multimedia Subsystem (IMS) amalgamates the core of telecommunication and Internet protocol (IP) network access to ease network traffic of the next-generation network (NGN). Since the coalescence of the NGN, malicious attacks can also disrupt multimedia services. This can lead to financial loss for telecom operators and loss of connection for users. This paper introduces an attack detection schema (ADS) that provides security from session initiation protocol (SIP) flooding attacks. The proposed schema is configured with the OpenOpenIMSCore to validate the accuracy of SIP session traffic. Similarly, the schema is imbedded with the OpenIMS client, which helps to detect and expose such attacks on the IMS client display. Since even a small flooding attack could clog the OpenOpenIMSCore, detection accuracy should be relatively higher to prevent OpenIMSCore from going down. The proposed schema includes a key authentication schema for proficiently analyzing SIP packets. The proposed authentication is placed between the transport and application layers. A network traffic tool, Ntop, is configured with the OpenOpenIMSCore to analyze SIP traffic, Real Time Transport Protocol (RTP) traffic and the throughput rate. Overall, the proposed schema of ADS improves reasonably well after it cuts off the attacker.

Inoculation Effect of Methylobacterium suomienseon Growth of Red Pepper under Different Levels of Organic and Chemical Fertilizers

Min-Kyoung Lee(이민경),Gil-Seung Lee(이길승),Woo-Jong Yim(임우종),In-Soo Hong(홍인수),Pitchai Palaniappan,Md. Ashaduzzaman Siddikee,Hari P. Deka Boruah,Munusamy Madhaiyan,Ki-Sup Ahn(안기섭),Tongmin Sa(사동민) 한국토양비료학회 2009 한국토양비료학회지 Vol.42 No.4

화학비료와 유기질비료를 시비 수준 및 Methylobacterium suomiense CBMB120의 접종이 고추 생육에 미치는 영향을 확인하기 위하여 유기질비료와 화학비료의 시비량을 권장시용수준의 100%, 75% 및 50%로 처리하고 Methylobacterium suomiense CBMB120을 접종 한 후 정식 후 19, 36, 및 166일에 작물의 높이를 측정하였으며 이식 후 166일에 건물량 측정하였다. 균주를 접종한 처리구의 식물체 높이는 정식 후 19, 36일에 각각 14.17%, 10.03% 증가하였다. 건물 중 역시 10.30%, 6.84% 증가하여 유의성 있는 차이를 나타내었다. 또한 균주 접종은 유기질 비료 100% 시용구는 36일 후 고도의 유의성(p<0.01)을 갖는 차이를 보였으며 화학 비료 100% 시용구는 19일 후 고도의 유의성(p<0.01)을 갖는 차이를 나타내었다. 화학비료 100% 시용구에 균주를 접종하지 않은 처리 구와 화학비료 75% 시용구에 균주를 접종한 처리구의 생육을 분석한 결과 유의성 있는 차이가 없는 것으로 나타났다. 이는 향후 다양한 처리량 및 처리방법의 연구를 통하여 Methylobacterium suomiense CBMB120 균주의 접종이 화학비료를 일정 부분 감비 할 수 있다는 가능성을 시사한다. Use of plant growth promoting symbiotic and non-symbiotic free-living beneficial bacteria as external source of nitrogen is a major research concern for sustainable crop production in the 21st century. In view of this, an experiment was conducted under controlled conditions to determine the effects of inoculation with Methylobacterium suomiense CBMB120, a plant growth promoting (PGP) root and shoot colonizer on red pepper, for the purpose of reducing external chemical nitrogen fertilization. Amendments with organic fertilizer and chemical fertilizer in the form of NPK were made at dosages of 50%, 75% and 100%, at 425 and 115 kg/ha-1 measurements. The soil type used was loam, with a pH of 5.13. The growth responses were measured as plant height at 19, 36 and 166 days after transplantation and final biomass production after 166 days. It was found that inoculation with M. suomiense CBMB120 promotes plant height increase during the active growth phase at 19 and 36 days by 14.17% and 10.03%, respectively. Thereafter, the bacteria inoculated plantlets showed canopy size increment. A highly significant inoculation effect on plant height at p<0.01 level was found for 100% level of organic matter and chemical amendment in red pepper plantlets after 36 days and 19 days from transplantation. Furthermore, there was a significantly higher (10.30% and 6.84%) dry biomass accumulation in M. suomiense CBMB120 inoculated plants compared to un-inoculated ones. A 25% reduction in the application of chemical nitrogen can be inferred with inoculation of M. suomiense CBMB120 at with comparable results to that of 100% chemical fertilization alone. Enumeration of total bacteria in rhizosphere soil confirms that the introduced bacteria can multiply along ther hizosphere soil. Large scale field study may lead to the development of M. suomiense CBMB120 as an efficient biofertilizer.