Role of Transporters and Enzymes in Metabolism and Distribution of 4-Chlorokynurenine (AV-101).

4-Chlorokynurenine (4-Cl-KYN, AV-101) is a prodrug of a NMDA receptor antagonist and is in clinical development for potential CNS indications. We sought to further understand the distribution and metabolism of 4-Cl-KYN, as this information might provide a strategy to enhance the clinical development of this drug. We used excretion studies in rats, in vitro transporter assays, and pharmacogenetic analysis of clinical trial data to determine how 4-Cl-KYN and metabolites are distributed. Our data indicated that a novel acetylated metabolite (N-acetyl-4-Cl-KYN) did not affect the uptake of 4-Cl-KYN across the blood-brain barrier via LAT1. 4-Cl-KYN and its metabolites were found to be renally excreted in rodents. In addition, we found that N-acetyl-4-Cl-KYN inhibited renal and hepatic transporters involved in excretion. Thus, this metabolite has the potential to limit the excretion of a range of compounds. Our pharmacogenetic analysis found that a SNP in N-acetyltransferase 8 (NAT8, rs13538) was linked to levels of N-acetyl-4-Cl-KYN relative to 4-Cl-KYN found in the plasma and that a SNP in SLC7A5 (rs28582913) was associated with the plasma levels of the active metabolite, 7-Cl-KYNA. Thus, we have a pharmacogenetics-based association for plasma drug level that could aid in the drug development of 4-Cl-KYN and have investigated the interaction of a novel metabolite with drug transporters.

Gamma irradiation effect on photocatalytic properties of Cu and Sr ions codoped PbS.

Gamma-irradiation effects on photocatalytic action of PbS nanocrystallites codoped with Cu and Sr ions were performed for organic dye degradation. The physical and chemical characterizations of these nanocrystallites were examined employing X-ray diffraction, Raman, and field emission electron microscopic analysis. The optical bandgaps of gamma-irradiated PbS with co-dopants have shifted from 1.95 eV (pristine PbS) to 2.45 eV in the visible spectrum. Under direct sunlight, the photocatalytic action of these compounds against methylene blue (MB) was investigated. Observations indicated that gamma-irradiated Pb(0.98)Cu0.01Sr0.01S nanocrystallite sample exhibits a higher photocatalytic degradation activity of 74.02% in 160 min and stability of 69.4% after three cycles, suggesting that gamma irradiation could potentially influence organic MB degradation. This is due to combined action of high-energy gamma irradiation (at an optimzed dose), which causes sulphur vacancies, and defects created by dopant ions, which alter the crystal structure by inducing strain in the crystal lattice, hence altering the crystallinity of PbS.

First-line nivolumab plus ipilimumab in metastatic non-small cell lung cancer: 5-year outcomes in Japanese patients from CheckMate 227 Part 1.

BACKGROUND: In CheckMate 227 Part 1 (NCT02477826), first-line nivolumab plus ipilimumab demonstrated long-term durable overall survival (OS) benefit versus chemotherapy in patients with metastatic non-small cell lung cancer (NSCLC), regardless of tumor programmed death ligand 1 (PD-L1) expression. We report results in Japanese patients with ≥ 5-year follow-up. METHODS: Adults with stage IV/recurrent NSCLC without EGFR/ALK aberrations were randomized 1:1:1 to nivolumab plus ipilimumab, nivolumab alone, or chemotherapy (patients with tumor PD-L1 ≥ 1%), or nivolumab plus ipilimumab, nivolumab plus chemotherapy, or chemotherapy (patients with tumor PD-L1 < 1%). Five-year efficacy and safety were assessed in Japanese patients. RESULTS: At 62.1 months' minimum follow-up, 143 Japanese patients with PD-L1 ≥ 1% or < 1% were randomized to nivolumab plus ipilimumab (n = 66) or chemotherapy (n = 77). Five-year OS rates were 46% with nivolumab plus ipilimumab versus 34% with chemotherapy (PD-L1 ≥ 1%) and 36% versus 19% (PD-L1 < 1%). Median duration of response was 59.1 versus 7.1 months (PD-L1 ≥ 1%) and 17.3 versus 3.0 months (PD-L1 < 1%). Among 5-year survivors treated with nivolumab plus ipilimumab (PD-L1 ≥ 1% and < 1%; n = 27), 59% (95% CI, 39%-75%) were off treatment for ≥ 3 years without receiving subsequent therapy. No new safety signals were observed. CONCLUSIONS: At 5-year follow-up, nivolumab plus ipilimumab continued to show long-term durable clinical benefit versus chemotherapy, regardless of tumor PD-L1 expression. Consistent with findings for the global population, these data support the use of nivolumab plus ipilimumab as first-line treatment in Japanese patients with metastatic NSCLC.

Biocatalytic One-Carbon Ring Expansion of Aziridines to Azetidines via a Highly Enantioselective [1,2]-Stevens Rearrangement.

We report enantioselective one-carbon ring expansion of aziridines to make azetidines as a new-to-nature activity of engineered "carbene transferase" enzymes. A laboratory-evolved variant of cytochrome P450BM3, P411-AzetS, not only exerts unparalleled stereocontrol (99:1 er) over a [1,2]-Stevens rearrangement but also overrides the inherent reactivity of aziridinium ylides, cheletropic extrusion of olefins, to perform a [1,2]-Stevens rearrangement. By controlling the fate of the highly reactive aziridinium ylide intermediates, these evolvable biocatalysts promote a transformation which cannot currently be performed using other catalyst classes.

Early starts and late finishes both reduce alertness and performance among short-haul airline pilots.

Flight crews are frequently required to work irregular schedules and, as a result, can experience sleep deficiency and fatigue. This study was conducted to determine whether perceived fatigue levels and objective performance varied by time of day, time awake, and prior night's sleep duration. Ninety-five pilots (86 male, 9 female) aged 33 years (±8) volunteered for the study. Participants completed a daily sleep diary, Samn-Perelli fatigue scale, and psychomotor vigilance task that were completed before and after each flight duty period and at the top-of-descent for each flight. Pilots experienced higher self-reported fatigue (EMM = 3.92, SE = 0.09, p < 0.001) and worse performance (Response speed: EMM = 4.27, SE = 0.08, p = 0.004) for late-finishing duties compared with early-starting duties (Samn-Perelli: EMM = 3.74, SE = 0.08; Response speed: EMM = 4.37, SE = 0.08), but had shorter sleep before early-starting duties (early: EMM = 6.94, SE = 0.10; late: EMM = 8.47, SE = 0.14, p < 0.001). However, pre-duty Samn-Perelli and response speed were worse (z = 4.18, p < 0.001; z = 3.05, p = 0.03; respectively) for early starts compared with late finishes (EMM = 2.74, SE = 0.19), while post-duty Samn-Perelli was worse for late finishes (EMM = 4.74, SE = 0.19) compared with early starts (EMM = 4.05, SE = 0.12). The results confirm that duty time has a strong influence on self-reported fatigue and performance. Thus, all flights that encroach on a biological night are targets for fatigue risk management oversight.

Surfactant induced copper vanadate (ß-Cu2V2O7, Cu3V2O8) for different textile dyes degradation.

In this study, pristine ß-Cu2V2O7, CTAB-ß-Cu2V2O7 and PVP-Cu3V2O8 were synthesized via hydrothermal method. The synthesized brown powder samples were exemplified using XRD, UV, PL, Raman and SEM studies. Further with XRD, we confirmed that the impurities were eradicated in addition of surfactant PVP. The bandgap obtained were 3.09 eV, 2.97 eV and 2.28 eV for ß-Cu2V2O7, CTAB-ß-Cu2V2O7 and PVP-Cu3V2O8. The morphology of ß-Cu2V2O7 was found to be cluster of nanoparticles with high level of agglomeration. While adding the surfactants (CTAB, PVP) the nano platelets were grown and uniformly arranged. The PVP-Cu3V2O8 sample exhibited 96%, 77% and 96% efficiency on reducing Methylene Blue, Rhodamine B and Malachite Green dyes. The enhancement of attaining complete efficiency by the PVP-Cu3V2O8 photocatalyst is attributed by the appropriate phase of host material and the PVP itself acted as a trapper for electron and hole which induced the rate of degrading toxic pollutants. The PVP-Cu3V2O8 photocatalyst will be enthusiastic and optimized aspirant for reducing organic pollutants and for wastewater management in future days.

Conversion and reducing agent effect on zero valent iron into Fe3O4 for photocatalytic degradation under UV light irradiation.

Conversion and reducing agent (NaBH4) effect on zero valent iron into Fe3O4 nanoparticles with diverse molar ratios of reducing agent was produced through chemical reduction technique. The structural, optical, vibrational analyses were executed via XRD, UV-Vis, Raman, and FT-IR analysis. The crystallite size obtained were 35 nm, 27 nm, and 18 nm for Fe:NaBH4 (1:1), Fe:NaBH4 (1:2) and Fe:NaBH4 (1:3). The morphology of the Fe:NaBH4 (1:1) was not in good orientation with higher dimensions. As explored in Fe:NaBH4 (1:2) and (1:3) samples, there is a proper growth of nanoneedles and nanosheets formation. This was due to the addition of reducing agent which greatly helped in enhancement of morphology. The prepared photocatalysts were tested to reduce Malachite Green (MG) under UV illumination. The pure dye solution obtained 57% efficiency after irradiation. Fe:NaBH4 (1:3) photocatalyst achieved 97% efficiency on reducing pollutants. The rate constant values calculated was 0.007, 0.013, 0.02 and 0.03 min-1 for pure, Fe: NaBH4 (1:1), Fe: NaBH4 (1:2) and Fe: NaBH4 (1:3) assisted MG samples. The as prepared photocatalyst is more potential one on removal of toxic pollutants from wastewater which is due to the better enhancement of nanoneedles and nanosheets oriented by the effect of reducing agent. The advantage of Fe3O4 nanoparticles for wastewater is that the removal of these nanoparticles can be ease with magnetic separation methods. On considering the advantage of removing of photocatalyst and efficiency, this prepared product is suitable one for wastewater remediation process in future days.

Facile hydrothermal synthesis of MXene@antimony nanoneedle composites for toxic pollutants removal.

A new 2D transition metal carbides family noted that MXene with antimony (Sb) nano-needles composites have demonstrated potential applications for photocatalytic dye degradations applications. Single-step synthesis of novel structures two/one-dimensional MXene@antimony nanoneedle (MX@Sb-H) nanocomposite-based photocatalysts is produced employing hydrothermal technique. The preparations and characterizations were compared with hand mixture preparations of pure TiO2@Sb and MXene (MX@Sb-M). The crystallographic structure was identified employing X-ray diffraction (XRD) studies and main sharp XRD peaks were observed with diffraction angle with orientations planes for all three samples TiO2@Sb, MX@Sb-M and MX@Sb-H. The micro-Raman spectroscopy explored key vibration modes centered at 151.72 and 637.52 cm-1 corresponding to Ti and Sb hybrid composites respectively. Fourier transform infrared spectroscopy (FTIR) spectrum of functional group peaks at 609.16 and 868.80 cm-1 revealed Ti-OH/Sb-O-C stretching. The morphological investigations of horizontal growth for "Sb" nanoneedle on MXene nanosheets were explored by scanning electron microscopy (SEM). The degradation efficiency was calculated. The efficiency calculated were 27%, 38%, 68% and 82% for MB solution, TiO2@Sb added MB, MX-Sb-M added MB and MX-Sb-H added MB solution and the efficiency were 32%, 38%, 50% and 65% for pure RhB solution, TiO2@Sb added RhB, MX-Sb-M added RhB and MX-Sb-H added RhB solution. The photocatalytic activity of TiO2@Sb, MX@Sb-M and MX@Sb-H was examined. Among these MX@Sb-H nanocomposite was demonstrated the high photocatalytic action in expressions of rate stability of photocatalytic dye degradations.

Enhanced visible light-driven photocatalytic performance of CdSe nanorods.

Cadmium selenide (CdSe) semiconductor nanorods are prepared in hydrothermal process using hydrazine hydrate (N2H4.H2O) and ammonia (NH3.H2O) as reducing agents. The reaction time is increased to 7 h and the amount of hydrazine hydrate used is also increased to 15 mL which have resulted in diminished stacking faults in the CdSe nanorods prepared. The crystal structure, morphological variations, and size of the prepared CdSe nanorods are examined by XRD analysis. The crystalline size of the CdSe nanorods is 20-30 nm in diameter. HRTEM images reveal the formation of high order CdSe nanorods of the length about 25-40 nm. The bandgap in the CdSe nanoparticles is determined to be 2.17 eV. The peak at 595 nm in photoluminescence (PL) spectrum indicates oxygen vacancy defects in the prepared CdSe sample. The variation of dielectric properties with respect to temperature and frequency of pelletized CdSe is studied. High photocatalytic efficiency (98%) of catalyst/H2O2 is also achieved for decomposition of Rhodamine-B dye.

Rare earth metal (Sm) doped zinc ferrite (ZnFe2O4) for improved photocatalytic elimination of toxic dye from aquatic system.

Wastewater remediation is the serious topic that must be taken into concern which would be a most crucial problem that destroys the natural properties as well as it has some worse effect on living organisms. By doing better wastewater management, the scarcity of water for domestic purposes can be eventually managed. Dyes are main organic pollutant that must be removed from wastewater. Pristine, 1% Sm doped and 2% Sm doped ZnFe2O4 were prepared through simple co-precipitation method. The materials were further analyzed for its structure, optical properties, rotational properties and morphology studies. These analyses were investigated with respect to X-ray diffraction, UV-vis spectroscopy, photoluminescence and scanning electron microscopic studies. XRD pattern of Pristine, 1% Sm doped and 2% Sm doped ZnFe2O4 was matched with JCPDS Card #89-1012 with cubic phase. Bandgap energy of prepared samples were 1.7 eV, 1.65 eV and 1.47 eV. The prepared cationic dye was degraded with help of visible light irradiation. 2% Sm doped ZnFe2O4 nanoparticles easily removed 65% of dye within 1 h duration. 2% Sm doped ZnFe2O4 was tested for its reusability and efficiency was stable for more than three cycles. This shows the stability of the sample towards degrading the cationic dye. By the doping of Samarium, ZnFe2O4 nanoparticles enthusiastically removed cationic dye and it proves to be an efficient candidate in removing dyes and can help in wastewater treatment in upcoming era.

Anionic surfactant assisted copper hydroxide for toxic dye removal from wastewater.

Wastewater treatment is the most important criteria that will deliberately reduce the water scarcity and to remove the organic pollutants from water. In this study, pure copper hydroxide (Cu(OH)2), 1% sodium dodecyl sulphate (SDS) and 2% sodium dodecyl sulphate (SDS) assisted Cu(OH)2 was prepared through co-precipitation technique. The prepared samples was investigated employing standard characterization studies. The X-Ray diffraction (XRD) pattern was confirmed with JCPDS card # 80-0656 with crystallite size of 25, 23 and 21 nm for pure Cu(OH)2, 1% SDS and 2% SDS assisted Cu(OH)2. The bandgap energy obtained for Cu(OH)2, 1% SDS and 2% SDS assisted Cu(OH)2 were 2.86 eV, 2.81 eV and 2.72 eV. The narrow bandgap of 2% SDS assisted Cu(OH)2 enhanced the photocatalytic activity than other two samples. The formation of nanoclusters and nanosheets were confirmed with Scanning Electron Microscopic (SEM) analysis. The thick clumsy nanosheets are formed as large nanoclusters in pure Cu(OH)2. Addition of SDS reduced the thickness of nanosheets and formed a little cluster. The prepared product photocatalytic performance was examined employing degradation of Methylene Blue (MB) dye. 2% SDS assisted Cu(OH)2 added MB dye solution was completely degraded with 98% efficiency. The reduce in particle size, high recombination of electron-hole pair with narrow bandgap made the 2% SDS assisted Cu(OH)2 candidate to give out potential output in eliminating the organic pollutants.

Pure and Ce-doped spinel CuFe2O4 photocatalysts for efficient rhodamine B degradation.

Wastewater management is becoming a serious issue worldwide. To enhance the reuse of wastewater, one has to remove toxic pollutants present in it. High amount of dye is present in wastewater, and to remove these dyes is the large scope of this research. Herein, we report production of pure and Ce-doped copper ferrite via hydrothermal route. The synthesized nanoparticles were collected and analyzed by basic characterization techniques. The bandgap energy calculated for pure, 1% Ce, and 2% Ce-doped CuFe2O4 was found to be 2.77, 2.57, and 2.36eV, respectively. Reduction in bandgap was attributed to the doping element. The shape and size of pure and Ce-doped products were investigated using a scanning electron microscope. Agglomeration was observed in the pure copper ferrite sample. In the Ce-doped sample, agglomeration was clearly reduced and the 2% Ce-doped CuFe2O4 sample showed growth of small nanoparticles. They showed complete growth and were arranged in a uniform manner without agglomeration. The surface area of the 2% Ce-CuFe2O4 sample was found to be 65.89 m2/g with 7.02 nm pore diameter. The photocatalytic activity of the prepared material was observed for rhodamine B degradation. The pure and catalyst-added dye was exposed under visible light. The samples were tested for UV. The efficiency obtained for pure dye solution, pristine CuFe2O4-added, and 1% Ce and 2% Ce-doped CuFe2O4-added dye solutions were 48%, 50%, 66%, and 88% within 2 h of irradiation. The 2% Ce-doped CuFe2O4 sample showed excellent photocatalytic activity as the bandgap and morphology were enhanced by doping an appropriate ratio of Ce ions.

Investigation on (Zn) doping and anionic surfactant (SDS) effect on SnO2 nanostructures for enhanced photocatalytic RhB dye degradation.

Herein we reported the effect of doping and addition of surfactant on SnO2 nanostructures for enhanced photocatalytic activity. Pristine SnO2, Zn-SnO2 and SDS-(Zn-SnO2) was prepared via simple co-precipitation method and the product was annealed at 600 °C to obtain a clear phase. The structural, optical, vibrational, morphological characteristics of the synthesized SnO2, Zn-SnO2 and SDS-(Zn-SnO2) product were investigated. SnO2, Zn-SnO2 and SDS-(Zn-SnO2) possess crystallite size of 20 nm, 19 nm and 18 nm correspondingly with tetragonal structure and high purity. The metal oxygen vibrations were present in FT-IR spectra. The obtained bandgap energies of SnO2, Zn-SnO2 and SDS-(Zn-SnO2) were 3.58 eV, 3.51 eV and 2.81 eV due to the effect of dopant and surfactant. This narrowing of bandgap helped in the photocatalytic activity. The morphology of the pristine sample showed poor growth of nanostructures with high level of agglomeration which was effectively reduced for other two samples. Product photocatalytic action was tested beneath visible light of 300 W. SDS-(Zn-SnO2) nanostructure efficiency showed 90% degradation of RhB dye which is 2.5 times higher than pristine sample. Narrow bandgap, crystallite size, better growth of nanostructures paved the way for SDS-(Zn-SnO2) to degrade the toxic pollutant. The superior performance and individuality of SDS-(Zn-SnO2) will makes it a potential competitor on reducing toxic pollutants from wastewater in future research.

Investigation of electrochemical performance of an efficient Ti2O3-CeO2 nanocomposite for enhanced pollution-free energy conversion applications.

The development of an economical, abundant, stable, and greatly active electrocatalyst for water oxidation is extremely important for future energy conversion system. Electrochemical water splitting is a new move toward H2 and O2 gas production. It can be used in sustainable and pollution-free energy conversion applications. In this work, Ti2O3-CeO2 nanocomposites were successfully synthesized with different molar ratios by facile hydrothermal method for electrochemical water oxidation. Mixed phase structure of Ti2O3-CeO2 nanocomposites was confirmed by X-ray diffraction spectra and well identified by highest peak of Ti2O3 in 2θ values of 33.0 and CeO2 in 2θ values of 28.5. The characteristic peaks from Raman and photoluminescence spectroscopy further confirmed Ti2O3-CeO2 nanocomposite formation. Existence of multidimensional nanostructures such as nanoparticles and small nanocubes of Ti2O3-CeO2 nanocomposites were investigated by scanning electron microscope images. Mesoporous nature of Ti2O3-CeO2 nanocomposites was further analyzed by Brunauer-Emmett-Teller analysis. The high surface area could benefit the Ti2O3-CeO2 nanocomposites with greatly improved oxygen evolution reaction (OER) performance. In three molar ratios, 1:3 M ratios of Ti2O3-CeO2 nanocomposites showed high catalytic action at overpotential of 244 mV. The best OER electrocatalyst was obtained by 1:3 M ratios of Ti2O3-CeO2 nanocomposites, which exhibited high current density and high specific capacitance values of 238 mA/g and 517 F/g, respectively. Therefore, Ti/Ce molar ratio played a crucial role in enhancing the OER performance.

Crystal structure of human lysosomal acid lipase and its implications in cholesteryl ester storage disease.

Lysosomal acid lipase (LAL) is a serine hydrolase that hydrolyzes cholesteryl ester (CE) and TGs delivered to the lysosomes into free cholesterol and fatty acids. LAL deficiency due to mutations in the LAL gene (LIPA) results in accumulation of TGs and cholesterol esters in various tissues of the body leading to pathological conditions such as Wolman's disease and CE storage disease (CESD). Here, we present the first crystal structure of recombinant human LAL (HLAL) to 2.6 Å resolution in its closed form. The crystal structure was enabled by mutating three of the six potential glycosylation sites. The overall structure of HLAL closely resembles that of the evolutionarily related human gastric lipase (HGL). It consists of a core domain belonging to the classical α/ß hydrolase-fold family with a classical catalytic triad (Ser-153, His-353, Asp-324), an oxyanion hole, and a "cap" domain, which regulates substrate entry to the catalytic site. Most significant structural differences between HLAL and HGL exist at the lid region. Deletion of the short helix, 238NLCFLLC244, at the lid region implied a possible role in regulating the highly hydrophobic substrate binding site from self-oligomerization during interfacial activation. We also performed molecular dynamic simulations of dog gastric lipase (lid-open form) and HLAL to gain insights and speculated a possible role of the human mutant, H274Y, leading to CESD.

Organic Datura metel Leaf Extract Mediated Inorganic Rare Earth La2O3 Nanocrystals Formation.

Development of sustainable synthesis of La2O3 nanocrystals formation employing Datura metel leaf extract was explored. The obtained nanocrystals were analyzed employing XRD, Raman, PL, FTIR, XPS and TEM characterizations. With increasing incubation and aging, the transformation of La(OH)3 to LaOOH and metal ellagate complex formation to La2O3 nanocrystals formation was observed. The obtained XRD results clearly revealed the transformation of lanthanum hydroxide to lanthanum oxide hydroxide and then to lanthanum oxide nanocrystals formation with 1, 4 and days. The influence of incubation and aging on La2O3 nanocrystals formation was discussed. Datura metel leaf extract product mixture over a period of incubation formed pure hexagonal lanthanum oxide nanocrystals.

Influence of Ni Doping in SnO2 Nanoparticles with Enhanced Visible Light Photocatalytic Activity for Degradation of Methylene Blue Dye.

In this article, Nickel doped rutile structure tin oxide (SnO2) nanoparticles have been prepared by simple chemical co-precipitation method and prepared samples were characterized by Powder X-ray Diffraction, Fourier transform infrared Spectroscopy, Microraman analysis, Photoluminescene Spectroscopy, UV-Visible Spectroscopy, Energy dispersive analysis and Field emission scanning electron microscope. XRD studies revealed the single phase tetragonal rutile structure with space group of P42/mnm. The average crystallite size of the particles was decreased from 27 to 22 nm with increasing Ni doping concentration. FTIR spectra confirmed the presence of various bands such as O-H, C-H, Sn-O-Sn. Raman modes Eg, A1g and B2g were assigned at 478, 630 and 740 cm-1 which confirmed the single phase of pure and Ni doped SnO2 nanoparticles. The photoluminescence spectra confirmed that the defect related emissions increased with increasing of Ni concentration. The UV absorption spectra showed that the absorption of the particles decreased with increasing Ni concentration and the band gap values decreased from 3.7 to 3.4 eV. EDX spectra confirmed the presence of Sn, Ni, O in pure and doped samples. The photocatalytic activity of the pure and Ni doped SnO2 nanoparticles were analyzed by using methylene blue dye under visible light irradiation. It is concluded Ni (7%) doped SnO2 nanoparticles have higher degradation efficiency compared to pure SnO2 nanoparticles.

Low Surface Energy and pH Effect on SnO2 Nanoparticles Formation for Supercapacitor Applications.

The SnO2 nanoparticles formation by hydrothermal method at different experimental conditions such as temperature, pH, reaction time, and capping agent (cetyltrimethylammonium bromide), was studied. X-ray diffraction results confirmed regular rutile crystal structure of SnO2. The characteristic Raman peak observed at 635 cm-1 corresponded to A1g modes of Sn-O vibrations. The study of optical property using photoluminescence confirmed the emissive spectra of SnO2. The infrared peak observed at 618 cm-1 corresponded to Eu modes of Sn-O vibrations of TO phonon because of E⊥ to c-axis. Scanning electron microscope images clearly revealed the formation of complete SnO2 nanoparticles. The unique SnO2 nanoparticles stacked together to form microspheres at pH-5 showed high specific capacitance of 274.8 F/g at a current density of 0.5 A/g. The observed results confirmed the feasibility of SnO2 nanoparticles being used as appropriate positive electrode candidate for supercapacitor applications.

Hexamine Role on Pseudocapacitive Behaviour of Cobalt Oxide (Co3O4) Nanopowders.

Influence of hexamine surfactant concentration on crystallite size, structure, morphology, vibrational and optical properties of cobalt oxide nanopowders were explored. The cobalt oxide nanopowders were synthesized by employing a simple chemical reduction method using cobalt (II) nitrate hexahydrate (Co(NO3)2 ·6H2O) as precursor and sodium borohydride (NaBH4) as reducing agent along with hexamine as surfactant. XRD studies revealed the formation of face-centered cubic (Fd3m) crystalline structure of Co3O4 with an average crystallite size of 8-18 nm. The observed prominent characteristic Raman active modes of A1g, Eg, and F2g revealed the formation of Co3O4 nanopowders. The optical properties of Co3O4 nanopowders are examined by photoluminescence spectra. The obtained IR results confirmed the formation of Co3O4 nanopowders. The band observed 569 cm-1 is the characteristic of the Co3+ ions in the octahedral hole vibration and the 665 cm-1 band is attributable to the Co2+ ions in the tetrahedral hole vibration in the cubic lattice. The estimated specific capacitance of the obtained Co3O4 nanopowders was 291 F/g at 10 mV/s which could be a potential candidate for pseudo capacitive nature of the active materials.

Structural, Optical and Magnetic Properties of NiO Nanopowders.

Nickel oxide (NiO) nanopowders were synthesized without using surfactant by chemical reduction technique. NaBH4 influence on structural, optical and magnetic properties of NiO product was investigated. XRD results revealed the formation of dominant single phase, cubic face centered nickel oxide. Raman peaks depicts the characteristic first-order transverse optical (TO) phonon, two phonon excitation (TO + LO), excitation (2LO) Raman mode vibrations of face centered cubic NiO. PL studies revealed the presence of strong emission band which is in good agreement with the intrinsic NiO product. FTIR studies explored metal oxygen vibrations of the obtained product. TEM results revealed the nanoscale product with spherical shape structures. VSM studies explored weak ferromagnetic behavior of the obtained product. High concentration of NaBH4 increases magnetization value and exhibits the typical weak ferromagnetic curve. Reducing agent played a vital role in the structural, optical and magnetic properties of the obtained NiO product.