P-1003 : Novel Catalyst for Hydrogen Generation from Sodium Borohydride Solution

( Palanichamy Krishnan ),양태현,박구곤,이원용,김창수 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.2

A novel catalyst for hydrogen generation from sodium borohydride solution was investigated. The hydrolysis of NaBH4 has been attracted because of the large hydrogen content of 10.9 wt.%. The special catalyst was necessary to produce hydrogen from NaBH4 solution. For this purpose, the catalysts such as Pt, Ru, PtRu supported on LiCoO2 and anion exchange resin were fabricated. The effects of support material, NaBH4 concentration, catalyst loading were discussed. References [1]S.C. Amendola, S.L. Sharp-Goldman, M.S. Janjua, M.T. Kelly, P.J. Petillo, M. Binder, An ultrasafe hydrogen generator: aqueous, alkaline borohydride solutions and Ru catalyst, J. Power Sources, 85 (2000) 186-189 [2]Yoshitsugu Kojima, Ken-ichirou Suzuki, Kazuhiro Fukumoto, Yasuaki Kawai,Masahiko Kimbara, Haruyuki Nakanishi, Shinichi Matsumoto, Development of 10kW-scale hydrogen generator using chemical hydride, J. Power Sources, 125 (2004)22-26

Novel Catalyst for Hydrogen Generation from Sodium Borohydride Solution

( Palanichamy Krishnan ),양태현,박구곤,이원용,김창수 한국공업화학회 2004 한국공업화학회 연구논문 초록집 Vol.2004 No.1

Synthesis of 2D/2D Structured Mesoporous Co3O4 Nanosheet/N-Doped Reduced Graphene Oxide Composites as a Highly Stable Negative Electrode for Lithium Battery Applications.

Sennu, Palanichamy,Kim, Hyo Sang,An, Jae Youn,Aravindan, Vanchiappan,Lee, Yun-Sung Wiley-VCH 2015 Chemistry - An Asian Journal Vol.10 No.8

<P>Mesoporous Co3O4 nanosheets (Co3 O4 -NS) and nitrogen-doped reduced graphene oxide (N-rGO) are synthesized by a facile hydrothermal approach, and the N-rGO/Co3O4 -NS composite is formulated through an infiltration procedure. Eventually, the obtained composites are subjected to various characterization techniques, such as XRD, Raman spectroscopy, surface area analysis, X-ray photoelectron spectroscopy (XPS), and TEM. The lithium-storage properties of N-rGO/Co3O4 -NS composites are evaluated in a half-cell assembly to ascertain their suitability as a negative electrode for lithium-ion battery applications. The 2D/2D nanostructured mesoporous N-rGO/Co3O4 -NS composite delivered a reversible capacity of about 1305 and 1501???mAh???g(-1) at a current density of 80???mA???g(-1) for the 1st and 50th???cycles, respectively. Furthermore, excellent cyclability, rate capability, and capacity retention characteristics are noted for the N-rGO/Co3O4 -NS composite. This improved performance is mainly related to the existence of mesoporosity and a sheet-like 2D hierarchical morphology, which translates into extra space for lithium storage and a reduced electron pathway. Also, the presence of N-rGO and carbon shells in Co3O4 -NS should not be excluded from such exceptional performance, which serves as a reliable conductive channel for electrons and act as synergistically to accommodate volume expansion upon redox reactions. Ex-situ TEM, impedance spectroscopy, and XPS, are also conducted to corroborate the significance of the 2D morphology towards sustained lithium storage.</P>

Formation of NiCo₂O₄ rods over Co₃O₄ nanosheets as efficient catalyst for Li–O₂ batteries and water splitting

Sennu, Palanichamy,Park, Hyo Seok,Park, Kwang Uk,Aravindan, Vanchiappan,Nahm, Kee Suk,Lee, Yun-Sung Elsevier 2017 Journal of catalysis Vol.349 No.-

<P><B>Abstract</B></P> <P>A 3D structured NiCo<SUB>2</SUB>O<SUB>4</SUB>@Co<SUB>3</SUB>O<SUB>4</SUB> hybrid was prepared by a two-step hydrothermal approach and subsequently employed as a highly efficient catalyst in oxygen reduction reactions (ORRs)/oxygen evolution reactions (OERs) and from a Li–O<SUB>2</SUB> battery perspective. The Co-NC possesses interconnected NiCo<SUB>2</SUB>O<SUB>4</SUB> nanorods grown over a Co<SUB>3</SUB>O<SUB>4</SUB> nanosheet structure, which facilitates charge transfer and enhances the electrical conductivity. Moreover, the 3D structured hybrids are directly used as a cathode catalyst for the Li–O<SUB>2</SUB> system and displayed a maximum in-depth-specific discharge capacity of 4386mAhg<SUP>−1</SUP>. In addition, significantly improved and stable cycling performance up to 60 cycles is observed compared with Co<SUB>3</SUB>O<SUB>4</SUB> nanosheets at the limited capacity range of 500mAhg<SUP>−1</SUP>. The excellent electrochemical performance of the NiCo<SUB>2</SUB>O<SUB>4</SUB>@Co<SUB>3</SUB>O<SUB>4</SUB> hybrid is mainly associated with the oxygen-deficient 3D architecture providing more catalytic active sites and can accommodate more discharge products. Further, ORR/OER activities of NiCo<SUB>2</SUB>O<SUB>4</SUB>@Co<SUB>3</SUB>O<SUB>4</SUB> hybrid in aqueous media are also evaluated in 0.1M KOH solution using the rotating ring disk electrode technique. For instance, the OER activity of NiCo<SUB>2</SUB>O<SUB>4</SUB>@Co<SUB>3</SUB>O<SUB>4</SUB> hybrid (apex current is 4.18mAcm<SUP>−2</SUP>) is an approximately 2.25 times higher than that of commercial RuO<SUB>2</SUB> catalyst (1.84mAcm<SUP>−2</SUP>). Since the catalytic activity in aqueous and organic medium is not necessarily the same, but of NiCo<SUB>2</SUB>O<SUB>4</SUB>@Co<SUB>3</SUB>O<SUB>4</SUB> hybrid exhibiting excellent ORR/OER characteristics in both cases is worth mentioning.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 3D structured NiCo<SUB>2</SUB>O<SUB>4</SUB>@Co<SUB>3</SUB>O<SUB>4</SUB> hybrid is prepared as catalyst for Li-O<SUB>2</SUB> battery. </LI> <LI> Excellent ORR/OER activity is observed in both aqueous and organic media. </LI> <LI> Li–O<SUB>2</SUB> system displayed a maximum in-depth-specific discharge capacity of 4386mAhg<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

ON SEQUENTIALLY g-CONNECTED COMPONENTS AND SEQUENTIALLY LOCALLY g-CONNECTEDNESS

Vijayashanthi, Palanichamy The Kangwon-Kyungki Mathematical Society 2021 한국수학논문집 Vol.29 No.2

In this paper, we introduce the definition of sequentially g-connected components and sequentially locally g-connected by using sequentially g-closed sets. Moreover, we investigate some characterization of sequentially g-connected components and sequentially locally g-connected.

Serotonin transporter occupancy of SKL10406 in humans: comparison of pharmacokineticpharmacodynamic modeling methods for estimation of occupancy parameters

박정신,한승훈,이종태,임동석,Palanichamy Ilankumaran,Jeffrey Meyer 대한임상약리학회 2014 Translational and Clinical Pharmacology Vol.22 No.2

SKL10406, triple monoamine reuptake inhibitor, is a novel antidepressant candidate. A PET studywas performed to investigate the occupancies of serotonin and dopamine transporters (SERT andDAT) in human brain, and the relationship between SKL10406 concentration and SERT occupancywas assessed using pharmacokinetic-pharmacodynamic (PK-PD) modeling methods. Fifteenhealthy volunteers were given SKL10406 100 mg/day for 6 days or 150 mg/day for 6 days after 100mg/day for 4 days. Each subject underwent full PK sampling for SKL10406 and PET scans at predose,4 h and 16 h after dosing at a steady state to investigate the occupancies of SERT and DAT using11C-DASB and 11C-PE2I, respectively. Naïve pooled method (NPM) and nonlinear mixed-effectmethods (ME) including a direct ME (DME) and an effect compartmental ME (EME) were used(NONMEM Ver. 7.2). Six and five subjects completed the studies for SERT and DAT, respectively. The final estimates of Emax (53.4%) and EC50 (11.8 ng/mL) from DME were relatively lower thanthose from NPM (Emax, 74.1%; EC50, 36.8 ng/mL) and EME (Emax, 68.6%; EC50, 40.2 ng/mL). DAToccupancy results were not modeled because of lower occupancies. The results showed that the dosageregimens may be applied in patient studies. However, difference between estimation methodsalerts that ME may not be a recommendable analysis tool for sparsely sampled PET scan data.

The Syntheses, Characterizations, and Photocatalytic Activities of Silver, Platinum, and Gold Doped TiO₂ Nanoparticles

Kumaresan Loganathan,Palanisamy Bommusamy,Palanichamy Muthaiahpillai,Murugesan Velayutham 대한환경공학회 2011 Environmental Engineering Research Vol.16 No.2

Different weight percentages of Ag, Pt, and Au doped nano TiO₂ were synthesized using the acetic acid hydrolyzed sol-gel method. The crystallite phase, surface morphology combined with elemental composition and light absorption properties of the doped nano TiO₂ were comprehensively examined using X-ray diffraction (XRD), N2 sorption analysis, transmission electron microscopic (TEM), energy dispersive X-ray, and DRS UV-vis analysis. The doping of noble metals stabilized the anatase phase, without conversion to rutile phase. The formation of gold nano particles in Au doped nano TiO₂ was confirmed from the XRD patterns for gold. The specific surface area was found to be in the range 50 to 85 m2/g. TEM images confirmed the formation a hexagonal plate like morphology of nano TiO₂. The photocatalytic activity of doped nano TiO₂ was evaluated using 4-chlorophenol as the model pollutant. Au doped (0.5 wt %) nano TiO₂ was found to exhibit higher photocatalytic activity than the other noble metal doped nano TiO₂, pure nano TiO₂ and commercial TiO₂ (Degussa P-25). This enhanced photocatalytic activity was due to the cathodic influence of gold in suppressing the electron-hole recombination during the reaction.

Dexterous template-free synthesis of ferrisilicate with MFI morphology using rice husk ash

Bhagiyalakshmi, Margandan,Anuradha, Ramani,Palanichamy, Muthiahpillai,Jang, Hyun Tae Elsevier 2010 Journal of non-crystalline solids Vol.356 No.23

<P><B>Abstract</B></P><P>Sodium silicate, the supernatant solution extracted from rice husk ash was used as silica source in hydrothermal synthesis of Fe ZSM-5 zeolites by an organic-free method. Characterization techniques such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), BET, X-Ray Fluorescence (XRF), Diffuse Reflectance Spectroscopy — Ultra Violet (DRS-UV) and Temperature-Programmed Desorption-ammonia (NH<SUB>3</SUB>-TPD) unambiguously confirm the formation of Fe ZSM-5. Phosphoric acid used in the synthesis, forms an oxo-anion complex with iron and this complex acts as surface directing agent in the formation of Fe ZSM-5 zeolites. Characterization results prove that rice husk ash can successfully be recycled as ferrisilicates with MFI morphology even in the absence of template.</P>

NaBH₄ 수용액 분해 수소 발생용 최적 촉매 개발

양태현(Yang, Tae-Hyun),이원용(Krishnan, Palanichamy),김창수(Lee, Won-Yong),Kim, Chang-Soo 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.06

Hydrogen generation by the hydrolysis of aqueous sodium borohydride (NaBH₄) solutions was studied using IRA-400 anion resin dispersed Pt. Ru catalysts and Lithium Cobalt oxide (LiCoO₂) supported Pt, Ru and PtRu catalysts. The performance of the LiCoO₂ supported catalysts is better than the ion exchange resin dispersed catalysts. There is a marked concentration dependence on the performance of the LiCoO₂ supported catalysts and the hydrogen generation rate goes down if the borohydride concentration is increased beyond 10%. The efficiency of PtRu- LiCoO₂ is almost double that of either Ru-LiCoO₂ or Pt-LiCoO₂ for NaBH₄ concentrations up to 10%.

Ultrastructural changes in cristae of lymphoblasts in acute lymphoblastic leukemia parallel alterations in biogenesis markers

Ritika Singh,Ritika Singh,Jayanth Kumar Palanichamy,T. C. Nag,Sameer Bakhshi,Archna Singh 한국현미경학회 2021 Applied microscopy Vol.51 No.1

We explored the link between mitochondrial biogenesis and mitochondrial morphology using transmission electron microscopy (TEM) in lymphoblasts of pediatric acute lymphoblastic leukemia (ALL) patients and compared these characteristics between tumors and control samples. Gene expression of mitochondrial biogenesis markers was analysed in 23 ALL patients and 18 controls and TEM for morphology analysis was done in 15 ALL patients and 9 healthy controls. The area occupied by mitochondria per cell and the cristae cross-sectional area was observed to be significantly higher in patients than in controls ( p -value = 0.0468 and p -value< 0.0001, respectively). The mtDNA copy numbers, TFAM , POLG, and c-myc gene expression were significantly higher in ALL patients than controls (all p -values< 0.01). Gene Expression of PGC-1α was higher in tumor samples. The analysis of the correlation between PGC-1α expression and morphology parameters i.e., both M/C ratio and cristae cross-sectional area revealed a positive trend ( r = 0.3, p = 0.1). The increased area occupied by mitochondria and increased cristae area support the occurrence of cristae remodelling in ALL. These changes might reflect alterations in cristae dynamics to support the metabolic state of the cells by forming a more condensed network. Ultrastructural imaging can be useful for affirming changes occurring at a subcellular organellar level.