01551nas a2200193   4500008004100000022001400041245009000055210006900145260010600214300001200320490000800332520078800340653003501128653002301163653001901186100001801205700002501223856010901248       2005                        eng d  a0038-109800aElectronic structure and ferromagnetism of polycrystalline Zn1-xCoxO (0 <= x <= 0.15)0 aElectronic structure and ferromagnetism of polycrystalline Zn1xC  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUN  a665-6690 v1343 a<p>The electronic structure of polycrystalline ferromagnetic Zn1-x,CoxO (0.05 &lt;= x &lt;= 0.15) and the oxidation state of Co in it, have been investigated. The Co-doped polycrystalline samples are synthesized by a combustion method and are ferromagnetic at room temperature. XPS and optical absorption studies show evidence for Co2+ ions in the tetrahedral symmetry, indicating, substitution of Co2+ in the ZnO lattice. However, powder XRD and electron diffraction data shock the presence of Co metal in the samples. This give evidence to the fact that some Co2+ ion are incorporated in the ZnO lattice which gives changes in the electronic structure whereas ferromagnetism comes from the Co metal impurities present in the samples. (c) 2005 Elsevier Ltd. All rights reserved.</p>10aMagnetically ordered materials10aOptical properties10aSemiconductors1 aDeka, Sasanka1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/electronic-structure-and-ferromagnetism-polycrystalline-zn1-xcoxo-0-001915nas a2200169   4500008004100000020001800041245010000059210006900159260009600228300001200324520119600336100001801532700002301550700002501573700001901598856012801617       2005                        eng d  a1-57498-218-400aHigh magnetic aspects of nanosized NiZn ferrite powders synthesized by an autocombustion method0 aHigh magnetic aspects of nanosized NiZn ferrite powders synthesi  aSan Francisco, CAbAmer Ceramic Soc, 735 Ceramic Place, Westerville, OH 43081-8720 USAcAUG  a149-1543 a<p>Nanocrystalline NiZn ferrite, Ni0.5Zn0.5Fe2O4, having particle size in the range 6-10 mn, has been synthesized by an auto-combustion method. The nanosized ferrite powder formed at a low temperature is annealed at different temperatures in the range 473-1273 K and characterized by X-ray diffraction, vibrating sample magnetometry, Mossbauer spectroscopy, transmission electron microscopy and scanning electron microscopy. Magnetic transition temperature broadening up to 773 K is observed for the nanosized sample, compared to the T-c = 563 K for the bulk material. Critical particle diameter (D-c) is found to be similar to 40 nm at which maximum coercivity is obtained for the powder sample annealed at 973 K. Similarly, high room temperature magnetization, comparable to that of the bulk material, is obtained for the powders annealed at 1073 K, with a maximum particle size of similar to 50 nm. Very little grain growth is observed for the powders annealed above 1073 K. The results show that, optimum magnetic properties can be achieved for fine particle NiZn ferrite powders synthesized by a low-temperature auto-combustion method and processed at relatively lower temperatures.</p>1 aDeka, Sasanka1 aDate, Sadgopal, K.1 aJoy, Pattayil, Alias1 aSoohoo, R., F.  uhttps://library.ncl.res.in/content/high-magnetic-aspects-nanosized-nizn-ferrite-powders-synthesized-autocombustion-method-001315nas a2200169   4500008004100000020001800041245007000059210006900129260010700198300001200305520063900317100001800956700002300974700002500997700001901022856010401041       2005                        eng d  a1-57498-218-400aSynthesis and magnetic properties of polycrystalline Co-doped ZnO0 aSynthesis and magnetic properties of polycrystalline Codoped ZnO  aSan Francisco, CAbAmer Ceram Soc; Japan Soc Powder & Powder Met; Int Magnet Assoc; Amer Phys SoccAUG  a913-9183 a<p>Nanocrystalline Zn1-xCoxO powders have been synthesized by a glycine-nitrate (GNP) and modified GNP methods. Ferromagnetism at room temperature and above is observed for the powder samples synthesized by GNP method. The saturation magnetization value at 300 K is obtained as 0.08 and 0.28 emu/g (at 1 T), respectively, for x = 0.05 and 0.1. Ferromagnetic transition occurs at 740 K and 770 K for the respective samples, which is much larger than that the reported in the literature for thin film samples. On the other hand, no ferromagnetism was observed, down to 10 K, for the compounds synthesized by the modified GNP method.</p>1 aDeka, Sasanka1 aDate, Sadgopal, K.1 aJoy, Pattayil, Alias1 aSoohoo, R., F.  uhttps://library.ncl.res.in/content/synthesis-and-magnetic-properties-polycrystalline-co-doped-zno-001393nas a2200205   4500008004100000022001400041245009500055210006900150260006900219300001100288490000800299520063300307653002300940653002300963653002400986653001101010100001801021700002501039856012301064       2006                        eng d  a0254-058400aCharacterization of nanosized NiZn ferrite powders synthesized by an autocombustion method0 aCharacterization of nanosized NiZn ferrite powders synthesized b  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcNOV  a98-1010 v1003 a<p>Nanocrystalline Ni0.5Zn0.5Fe2O4 with average particle size of similar to 9 nm has been synthesized by an autocombustion method and characterized by powder XRD, TEM and room temperature magnetic measurements. High room temperature magnetization comparable to that of the bulk material is obtained for the nanosized powders annealed at 800 degrees C, with a maximum particle size of similar to 54 nm. The results show that optimum properties can be achieved for NiZn ferrite powders synthesized by the present autocombustion method and processed at relatively lower temperatures. (c) 2005 Elsevier B.V. All rights reserved.</p>10aChemical synthesis10aMagnetic materials10amagnetic properties10aOxides1 aDeka, Sasanka1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/characterization-nanosized-nizn-ferrite-powders-synthesized-autocombustion-method-001318nas a2200169   4500008004100000022001400041245016700055210006900222260008300291300002300374490000700397520056300404100001800967700001900985700002501004856011901029       2006                        eng d  a1098-012100aExperimental comparison of the structural, magnetic, electronic, and optical properties of ferromagnetic and paramagnetic polycrystalline Zn1-xCoxO (x=0,0.05,0.1)0 aExperimental comparison of the structural magnetic electronic an  aONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USAbAMERICAN PHYSICAL SOCcJUL  aArticle No. 0332010 v743 a<p>Ferromagnetism at room temperature is observed in one case whereas paramagnetism down to 12 K is observed in the second case when polycrystalline Zn1-xCoxO is synthesized under almost identical conditions. Identical x-ray diffraction, optical absorption, and x-ray photoelectron spectroscopy results indicate the incorporation of Co2+ ions in the ZnO lattice in both cases. However, electron diffraction studies show the presence of Co metal impurities in the ferromagnetic samples, indicating that pure Co doped ZnO is not likely to be ferromagnetic.</p>1 aDeka, Sasanka1 aPasricha, Renu1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/experimental-comparison-structural-magnetic-electronic-and-optical-properties-101358nas a2200157   4500008004100000022001400041245008400055210006900139260012500208300002300333490000700356520068100363100001801044700002501062856011301087       2006                        eng d  a0003-695100aFerromagnetism induced by hydrogen in polycrystalline nonmagnetic Zn0.95Co0.05O0 aFerromagnetism induced by hydrogen in polycrystalline nonmagneti  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJUL  aArticle No. 0325080 v893 a<p>Polycrystalline Zn0.95Co0.05O is found to be paramagnetic at room temperature and down to 12 K. Optical measurements prove the incorporation of Co2+ ions inside the ZnO lattice in the tetrahedral site. When the paramagnetic sample is heated in Ar/H-2 at 1125 K for 2 h, ferromagnetism with a very high value of magnetization is observed at room temperature. Hydrogen reduction does not affect the substituted Co2+ ions inside the wurtzite crystal lattice as evidenced from optical studies. X-ray diffraction studies show the presence of Co metal after the reduction process which is the origin of room temperature ferromagnetism. (c) 2006 American Institute of Physics.</p>1 aDeka, Sasanka1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/ferromagnetism-induced-hydrogen-polycrystalline-nonmagnetic-zn095co005o-101474nas a2200241   4500008004100000022001400041245008600055210006900141260007300210300001200283490000800295520063300303653002400936653001400960653001800974653002300992653000801015100001801023700001801041700002501059700002801084856012001112       2006                        eng d  a0304-885300aSize-dependent magnetic properties of nanocrystalline yttrium iron garnet powders0 aSizedependent magnetic properties of nanocrystalline yttrium iro  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a212-2190 v3013 a<p>Yttrium iron garnet (YIG) powders with particle sizes of 9, 14, 25 and 60 nm have been synthesised and their magnetic properties have been studied as a function of particle size and temperature. The particles with sizes of 9 and 14 nm exhibited superparamagnetism. The blocking temperature (T-B) decreased with decreasing particle size, whereas the anisotropy constant (K) increased. The saturation magnetisation (M-s) decreased with decreasing particle size. These variations are attributed to large surface-to-volume ratios in nanoparticles where the surface moments are predominant. (c) 2005 Published by Elsevier B.V.</p>10aanisotropy constant10aMagnetism10aNanoparticles10aSuperparamagnetism10aYIG1 aRajendran, M.1 aDeka, Sasanka1 aJoy, Pattayil, Alias1 aBhattacharya, Asish, K.  uhttps://library.ncl.res.in/content/size-dependent-magnetic-properties-nanocrystalline-yttrium-iron-garnet-powders-001417nas a2200157   4500008004100000022001400041245012500055210006900180260006700249300001400316490000700330520074800337100001801085700002501103856013101128       2007                        eng d  a0002-782000aEnhanced permeability and dielectric constant of NiZn ferrite synthesized in nanocrystalline form by a combustion method0 aEnhanced permeability and dielectric constant of NiZn ferrite sy  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcMAY  a1494-14990 v903 a<p>The performance parameters of Ni0.5Zn0.5Fe2O4, synthesized in the nanocrystalline form by an autocombustion method, have been investigated. The sample sintered at 1200 degrees C, with Bi2O3 as additive shows a very high value of initial permeability mu'(i) of &gt; 400 at 1 MHz, with low loss. Similarly, a very high dielectric constant is obtained at lower frequencies. The results show that optimum magnetic and electrical properties can be achieved for the NiZn ferrite nanocrystalline powders synthesized by the present autocombustion method and sintered at a relatively lower temperature of 1200 degrees C when compared with a temperature of 1400 degrees C required for the materials synthesized by the conventional ceramic method.</p>1 aDeka, Sasanka1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/enhanced-permeability-and-dielectric-constant-nizn-ferrite-synthesized-nanocrystalline-form00946nas a2200157   4500008004100000022001400041245008600055210006900141260011000210300001200320490000700332520029700339100001800636700002500654856010900679       2007                        eng d  a0959-942800aEnhancement of the phase transformation temperature of gamma-Fe2O3 by Zn2+ doping0 aEnhancement of the phase transformation temperature of gammaFe2O  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a453-4560 v173 a<p>The phase transformation temperature of gamma-Fe2O3 to alpha-Fe2O3 is increased with Zn2+ doping and enhancement of the transition temperature by similar to 100 degrees C is obtained for doping of &gt;= 15 mol% Zn in nanocrystalline gamma-Fe2O3 synthesized by an autocombustion method.</p>1 aDeka, Sasanka1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/enhancement-phase-transformation-temperature-gamma-fe2o3-zn2-doping-001815nas a2200205   4500008004100000022001400041245006400055210006400119260010600183300001200289490000800301520106000309653002501369653003501394653002401429653001701453100001801470700002501488856009601513       2007                        eng d  a0038-109800aSynthesis and magnetic properties of Mn doped ZnO nanowires0 aSynthesis and magnetic properties of Mn doped ZnO nanowires  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcAPR  a190-1940 v1423 a<p>Mn doped ZnO nanowires have been synthesized using a simple autocombustion method. The as-synthesized Mn doped ZnO nanowires were characterized by X-ray diffraction and transmission electron microscopy. An increase in the hexagonal lattice parameters of ZnO is observed on increasing the Mn concentration. Optical absorption studies show an increment in the band gap with increasing Mn content, and also give evidence for the presence of Mn2+ ions in tetrahedral sites. All Zn1-xMnxO (0 &lt;= x &lt;= 0.25) samples are paramagnetic at room temperature. However, a large increase in the magnetization is observed below 50 K. This behavior, along with the negative value of the Weiss constant obtained from the linear fit to the susceptibility data below room temperature, indicate ferrimagnetic behavior. The origin of ferrimagnetism is likely to be either the intrinsic characteristics of the Mn doped samples, or due to some spinel-type impurity phases present in the samples that could not be detected. (c) 2007 Elsevier Ltd. All rights reserved.</p>10aCombustion synthesis10adiluted magnetic semiconductor10amagnetic properties10aMn doped ZnO1 aDeka, Sasanka1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/synthesis-and-magnetic-properties-mn-doped-zno-nanowires01727nas a2200229   4500008004100000022001400041245011400055210006900169260007400238300001100312490000800323520088300331653001201214653002401226653002701250653001801277100001501295700001901310700001801329700002501347856012501372       2008                        eng d  a0304-384300aMagnetic and Mossbauer spectroscopic studies of NiZn ferrite nanoparticles synthesized by a combustion method0 aMagnetic and Mossbauer spectroscopic studies of NiZn ferrite nan  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcAPR  a99-1070 v1833 a<p>The properties of nanocrystalline Ni(0.5)Zn(0.5)Fe(2)O(4) synthesized by an auto-combustion method have been investigated by magnetic measurements and Mossbauer spectroscopy. The as-synthesized single phase nanosized ferrite powder is annealed at different temperatures in the range 673-1,273 K to obtain nanoparticles of different sizes. The powders are characterized by powder X-ray diffraction, vibrating sample magnetometer, transmission electron microscopy and Mossbauer spectroscopy. The as-synthesized powder with average particle size of similar to 9 nm is superparamagnetic. Magnetic transition temperature increases up to 665 K for the nanosized powder as compared to the transition temperature of 548 K for the bulk ferrite. This has been confirmed as due to the abnormal cation distribution, as evidenced from room temperature Mossbauer spectroscopic studies.</p>10aFerrite10amagnetic properties10aMossbauer spectroscopy10aNanoparticles1 aSreeja, V.1 aVijayanand, S.1 aDeka, Sasanka1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/magnetic-and-mossbauer-spectroscopic-studies-nizn-ferrite-nanoparticles-synthesized-001322nas a2200145   4500008004100000245005700041210005700098260010900155300001200264490000600276520077100282100001801053700001601071856008901087       2008                        eng d00aStudies on ZnO based diluted magnetic semiconductors0 aStudies on ZnO based diluted magnetic semiconductors  aNew Orleans, LAbMinerals, Metals & Materials Soc, 184 Thorn Hill Rd, Warrendale, PA 15086-7514 USAcMAR  a373-3780 v33 a<p>The observation of ferromagnetism in the transition metal (TM) doped wide band gap nonmagnetic semiconductor ZnO opened up a new area of research because of the potential applications in spintronics devices. These ZnO based diluted magnetic semiconductors (DMS) combine their transport and optical properties with magnetism. We have carried out synthesis and studies on the magnetic and optical properties on TM doped ZnO powders in nanocrystalline form. Our studies give evidence for the origin of ferromagnetism as extrinsic due to the presence of metal nanoclusters as secondary phases in the Co and Ni doped ZnO systems although the optical and electronic structure studies indicate the incorporation of divalent metal ions inside the ZnO crystal lattice.</p>1 aDeka, Sasanka1 aJoy, P., A.  uhttps://library.ncl.res.in/content/studies-zno-based-diluted-magnetic-semiconductors01416nas a2200205   4500008004100000022001400041245008100055210006900136260009500205300001400300490000600314520065400320653002200974653002000996653002301016653001701039100001801056700002501074856011101099       2008                        eng d  a1533-488000aSuperparamagnetic nanocrystalline ZnFe2O4 with a very high curie temperature0 aSuperparamagnetic nanocrystalline ZnFe2O4 with a very high curie  a25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USAbAMER SCIENTIFIC PUBLISHERScAUG  a3955-39580 v83 a<p>Studies on the magnetic properties of nanocrystalline ZnFe2O4 synthesized by an autocombustion method are reported. Superparamagnetic behavior is observed for the nanocrystalline materials with particle sizes of 8 nm and 17 nm, with superparamagnetic blocking temperatures of 65 K and 75 K, respectively. Magnetic hysteresis with very large coercivities of 533 Oe and 325 Oe, respectively, are observed at 12 K. Studies on the temperature variation of the magnetization above room temperature indicate that the Curie temperature is as high as similar to 800 K when compared to the paramagnetic nature of bulk zinc ferrite at room temperature.</p>10aCurie temperature10aNanocrystalline10aSuperparamagnetism10aZinc Ferrite1 aDeka, Sasanka1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/superparamagnetic-nanocrystalline-znfe2o4-very-high-curie-temperature-001562nas a2200241   4500008004100000022001400041245010800055210006900163260009200232300001200324490000600336520069000342653001501032653001201047653002401059653001801083653002001101653001701121100001801138700002501156700002001181856011901201       2009                        eng d  a1947-293500aSingle step synthesis and properties of M/MFe2O4 and PVDF/M/MFe2O4 (M = Co, Ni) magnetic nanocomposites0 aSingle step synthesis and properties of MMFe2O4 and PVDFMMFe2O4   a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScDEC  a262-2680 v13 a<p>Metal/ferrite nanocomposites (M/MFe2O4; M = Co, Ni), consisting of nanoparticles of a metal and the corresponding metal ferrite, have been synthesized under in situ conditions by a simple and single step process. The metal/ferrite nanocomposites embedded in a polymer matrix have been prepared by a simple hot-pressing method. The performance parameters such as magnetization, coercivity, permeability and dielectric constant of the two- and three-phase nanocomposite systems are compared. The coercivity increases and the permeability decreases with increasing polymer content in the three-phase composite. Enhancement of the dielectric constant is observed at low frequencies.</p>10aDielectric10aFerrite10amagnetic properties10aNanocomposite10aNanocrystalline10apermeability1 aDeka, Sasanka1 aJoy, Pattayil, Alias1 aKumar, Pratheep  uhttps://library.ncl.res.in/content/single-step-synthesis-and-properties-mmfe2o4-and-pvdfmmfe2o4-m-co-ni-magnetic-001679nas a2200205   4500008004100000022001400041245008500055210006900140260011000209300001600319490000600335520088800341100001801229700002201247700002001269700001801289700003001307700002001337856011601357       2014                        eng d  a2046-206900aPreferential growth of Au on CdSe quantum dots using langmuir-blodgett technique0 aPreferential growth of Au on CdSe quantum dots using langmuirblo  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcNOV  a64535-645410 v43 a<p>Oleyl amine capped CdSe quantum dots (QD) were synthesised by hot injection technique. These QDs formed a self-assembled monolayer on an aqueous subphase of a Langmuir-Blodgett (LB) trough. Here, in this report we introduced a simple but very efficient route to form a metal (Au)-QD hybrid nanostructure via the LB technique. In this method, the metal counterpart of the hybrid nanostructure could be deposited exclusively on one side of the QDs. The formation of stable monolayer of QDs was evidenced from a surface pressure-area (P-A) isotherm. The development of gold tip was confirmed and monitored by detailed TEM study on the monolayer deposited on TEM grids from the LB trough. Other characterizations like UV-Vis spectroscopy, FTIR, XPS and EDX also suggested the same. Oleyl amine was shown to act both as a reducing agent as well as a capping agent in this strategy.</p>1 aDas, Subhasis1 aSatpati, Biswarup1 aChauhan, Himani1 aDeka, Sasanka1 aGopinath, Chinnakonda, S.1 aBala, Tanushree  uhttps://library.ncl.res.in/content/preferential-growth-au-cdse-quantum-dots-using-langmuir-blodgett-technique-001154nas a2200193   4500008004100000022001400041245009100055210006900146260011000215300001400325490000700339520038900346100001800735700001600753700002200769700003000791700001800821856012100839       2016                        eng d  a1359-734500aExploration of magnetically separable Ag@AgxNiy core/graded-alloy-shell nanostructures0 aExploration of magnetically separable AgAgxNiy coregradedalloysh  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUN  a8737-87400 v523 a<p>We report novel bimetallic Ag@AgxNiy core@graded-alloy-shell nanoparticles (CGAS NPs), i.e. single Ag core NPs shelled by an AgxNiy graded alloy and stabilized by the CTAB surfactant employing a novel synthesis method. These Ag@AgxNiy CGAS NPs demonstrated superior catalytic performance in the synthesis of biologically active 3-amino alkylated indoles under green conditions.</p>1 aKumar, Mukesh1 aSoni, Kiran1 aSatpati, Biswarup1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/exploration-magnetically-separable-agagxniy-coregraded-alloy-shell-nanostructures01619nas a2200217   4500008004100000022001400041245007500055210006900130260011000199300001600309490000600325520081000331100001801141700002201159700002001181700001801201700002701219700003001246700002001276856010501296       2016                        eng d  a2046-206900aSeeding of Au on CdSe/CdS nanoplates using Langmuir-Blodgett technique0 aSeeding of Au on CdSeCdS nanoplates using LangmuirBlodgett techn  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a14658-146650 v63 a<p>Oleyl amine capped CdSe/CdS nanoplates were synthesized by hot injection technique which formed a stable monolayer over both a water subphase and an aqueous HAuCl4 subphase using a Langmuir-Blodgett trough. Au islands were generated at the edge as well as on one specific surface of the flat nanoplates by exploiting the reducing capacity of oleyl amine to form Au nanoseeds from AuCl4- ions. The initial Au nanoseeds changed to a shell surrounding these nanoplates on prolonged exposure to the subphase containing the Au precursor. Monolayer of the hybrid structures was deposited onto suitable substrates for characterization by a number of different techniques and to study the photocatalytic activity. The same substrate with the monolayers could be re-used in several cycles of photocatalysis.</p>1 aDas, Subhasis1 aSatpati, Biswarup1 aChauhan, Himani1 aDeka, Sasanka1 aGhosalya, Manoj, Kumar1 aGopinath, Chinnakonda, S.1 aBala, Tanushree  uhttps://library.ncl.res.in/content/seeding-au-cdsecds-nanoplates-using-langmuir-blodgett-technique-002927nas a2200325   4500008004100000245010200041210006900143260000800212490000600220520185800226653003302084653001302117653001202130653003002142653002002172653002502192653001802217653001402235653001002249653002102259653001602280653002002296653002002316653003902336100002302375700002902398700003002427700001802457856012602475       2017                        eng d00aCopper Cobalt Sulfide Nanosheets Realizing a Promising Electrocatalytic Oxygen Evolution Reaction0 aCopper Cobalt Sulfide Nanosheets Realizing a Promising Electroca  cSEP0 v73 a<p><span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; background-color: rgb(248, 248, 248);">Nanostructured CuCo2S4, a mixed metal thiospinel, is found to be a benchmark electrocatalyst for oxygen evolution reaction (OER) in this study with a low overpotential, a low Tafel slope, a high durability, and a high turnover frequency (TOF) at lower mass loadings. Nanosheets of CuCo2S4 are realized from a hydrothermal synthesis method in which the average thickness of the sheets is found to be in the range of 815 nm. Aggregated nanosheets form a highly open hierarchical structure. When used as an electrocatalyst, CuCo2S4 nanosheets offer an overpotential value of 310 mV at a 10 mA cm(2) current density, which remains consistent for 10000 measured cycles in a 1 M KOH electrolyte. A chronoamperometric study reveals constant oxygen evolution for 12 h at a 10 mV s(-1) scan rate without any degradation of the activity. Furthermore, the calculated mass activity of the CuCo2S4 electrocatalyst is found to be 14.29 A/g and to afford a TOF value of 0.1431 s(-1) at 310 mV at a mass loading of 0.7 mg cm(-2). For comparison, nanostructures of Co3S4 and Cu0.5Co2.5S4 have been synthesized using a similar method followed for CuCo2S4. When compared to the OER activities among these three thiospinels and standard IrO2, CuCo2S4 nanosheets offered the highest OER activities at the same mass loading (0.7 mg/cm(-2)). Extensive X-ray photoelectron spectroscopy and electron paramagnetic resonance analyses for a mechanistic study reveal that introduction of Cu into the Co3S4 lattice enhances the oxygen evolution and kinetics by offering Cu2+ sites for utilitarian adsorption of OH, O, and OOH reactive species and also by offering a highly active high-spin state of octahedral Co3+ for OER catalysis.</span></p>10aBifunctional Electrocatalyst10aCatalyst10aCuco2s410aEfficient Electrocatalyst10aelectrocatalyst10aElectronic-structure10aNanoparticles10aNanosheet10aoxide10aoxygen evolution10aperformance10aRecent Progress10aWater oxidation10aWater Splitting Hydrogen Evolution1 aChauhan, Meenakshi1 aReddy, Kasala, Prabhakar1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/copper-cobalt-sulfide-nanosheets-realizing-promising-electrocatalytic-oxygen-evolution01646nas a2200229   4500008004100000022001400041245009800055210006900153260000900222300001400231490000700245520085500252100001801107700002601125700002201151700001801173700001801191700002701209700003001236700002001266856013001286       2018                        eng d  a1144-054600aDeposition of Au nanoparticles inside porous CeO2 nanocubes using Langmuir-Blodgett technique0 aDeposition of Au nanoparticles inside porous CeO2 nanocubes usin  cJAN   a1379-13860 v423 a<p>Porous 3D CeO2 nanocubes were synthesized using hot injection technique. These nanocubes were able to form a stable monolayer over water and HAuCl4 subphase in Langmuir-Blodgett (LB) trough due to the presence of surface capped oleic acid and oleylamine. CeO2-Au nanocomposites were synthesized exploiting the ability of oleylamine to reduce AuCl4 ions to Au-0, via LB method. CeO2 nanocubes gave rise to excellent long-range assembly at air/water interface and gold nanoparticles were formed inside these porous nanocubes without disturbing this arrangement. The formation of a stable monolayer was evidenced from the surface pressure-area (P-A) isotherm. The development of Au nanoparticles was confirmed with great effort from a comprehensive study using UV-Vis spectroscopy, XRD, XPS, FTIR, TEM, STEM, EDX, tomography and chemical mapping.</p>1 aDas, Subhasis1 aBhattacharjee, Gourab1 aSatpati, Biswarup1 aKumar, Mukesh1 aDeka, Sasanka1 aGhosalya, Manoj, Kumar1 aGopinath, Chinnakonda, S.1 aBala, Tanushree  uhttps://library.ncl.res.in/content/deposition-au-nanoparticles-inside-porous-ceo2-nanocubes-using-langmuir-blodgett-technique02443nas a2200265   4500008004100000022001400041245016400055210006900219260000900288300001400297490000600311520153400317653001101851653002301862653001501885653001801900653001901918653002001937100001701957700001901974700001801993700002102011700001802032856012702050       2019                        eng d  a2168-048500aDirect thermal polymerization approach to N-rich holey carbon nitride nanosheets and their promising photocatalytic H-2 evolution and charge-storage activities0 aDirect thermal polymerization approach to Nrich holey carbon nit  cMAY   a9428-94380 v73 a<p>Energy conversion and energy storage are two crucial challenges in green chemistry that have attracted tremendous attention for the last several decades. In this work, we have addressed both issues by synthesizing nitrogen-rich, few-layer-thick holey graphitic carbon nitride (g-C3N4) nanosheets by a simple, novel, direct thermal polymerization method, which is found to be very good in photocatalytic H-2 evolution reaction (energy-conversion) and charge-storage supercapacitor (energy-storage) applications. This as-synthesized conjugated polymer semiconductor (obtained stoichiometry C3N4.8) with unique structural and morphological advantages exhibits superior photocatalytic water splitting activity to H-2 evolution (2 620 mu mol h(-1) g(-1)) without the help of any cocatalysts under visible light in the presence of 20% triethanolamine (TEOA). The calculated apparent quantum yield is 8.5% at 427 nm, and the rate of photocatalytic hydrogen generation remained constant for nine consecutive catalytic cycles (9 h photocatalysis). The present material also shows electrochemical double layer capacitor (EDLC) behavior in alkaline electrolyte, where a symmetric coin cell device consisting of this electrode material without any large area support or conductive filler delivers high specific capacitance (275 F g(-1)), energy density (30 Wh kg(-1)), and power density (6651 W kg(-1)), and the supercapacitor cell can retain &gt;98% capacitance efficiency up to 10 000 measured cycles at various current densities.</p>
10ag-C3N410aHydrogen evolution10ananosheets10aPhotocatalyst10asupercapacitor10awater splitting1 aAntil, Bindu1 aKumar, Lakshya1 aReddy, K., P.1 aGopinath, C., S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/direct-thermal-polymerization-approach-n-rich-holey-carbon-nitride-nanosheets-and-their02393nas a2200205   4500008004100000022001400041245012000055210006900175260000900244300001400253490000600267520164700273100002301920700001601943700002001959700002901979700003002008700001802038856013102056       2019                        eng d  a2050-748800aPromising visible-light driven hydrogen production from water on a highly efficient CuCo2S4 nanosheet photocatalyst0 aPromising visiblelight driven hydrogen production from water on   cMAR   a6985-69940 v73 a<p>Here we report the development of CuCo2S4 nanosheets (NSs) as a promising semiconductor photocatalyst for the first time for water splitting reactions under visible light ( 420 nm) conditions, without the support of any noble metal co-catalyst. These NSs were produced via a simple hydrothermal route and have desirable properties with a band gap of 2.24 eV, and are photo-catalytically active under visible light with an apparent quantum yield (AQY) of 2.48%. Under visible light, CuCo2S4 NSs exhibit excellent weight-normalized photoactivity that generates approximate to 25900 mol h(-1) H-2 for 1 g of material with sulphide + sulphite as the sacrificial agent under 7.68 mW cm(-2) illumination, which is the best evolution reported for any chalcogenide semiconductor material without any co-catalyst to date with unprecedented long-term operational stability (up to 12 h study time). The rate and number of hydrogen gas molecules produced are 8.2855 x 10(15) s(-1) cm(-2) which remained constant for three catalytic cycles with a turnover frequency (TOF) value of 0.017 s(-1). The effect of Cu substitution on photoactivity was also investigated for comparative studies and it was found that CuCo2S4 NSs show superior activity to Cu0.5Co2.5S4 and Co3S4. These CuCo2S4 NSs absorb the entire visible range of the spectrum from 420 to 800 nm, and have a highly populated density of states at the Fermi level and a high donor concentration of 7.22 x 10(18) cm(-3) which have been evaluated by Mott-Schottky analysis and favourable adsorption of H+ on S-sites and conversion to H-2 corroborate their efficient photocatalytic activity.</p>
1 aChauhan, Meenakshi1 aSoni, Kiran1 aKarthik, P., E.1 aReddy, Kasala, Prabhakar1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/promising-visible-light-driven-hydrogen-production-water-highly-efficient-cuco2s4-nanosheet02344nas a2200181   4500008004100000022001400041245017700055210006900232260000800301300001600309490000600325520161800331100001701949700001701966700003001983700001802013856013102031       2020                        eng d  a2050-748800aDirected holey and ordered g-C(3)N(4.5)nanosheets by a hard template nanocasting approach for sustainable visible-light hydrogen evolution with prominent quantum efficiency0 aDirected holey and ordered gC3N45nanosheets by a hard template n  cJUL  a13328-133390 v83 a<p>It is desirable yet challenging to synthesize a highly ordered holey carbon nitride material with excess nitrogen atoms for a sustainable solar H(2)evolution. Herein, we report the development of directed highly ordered nitrogen-rich honeycomb-like mesoporous carbon nitride nanosheets by using a novel synthetic approach for this purpose. The unique formation route, surface structure and charge carrier dynamics of the two dimensional holey nanosheets are comprehensively monitored and confirmed by SAXS, HRTEM, AFM, BET, XPS and TRPL analyses. Non-stoichiometric high nitrogen content mesoporous nanosheets with the final stoichiometry of g-C(3)N(4.5)acquiring a high specific surface area (382 m(2)g(-1)), remarkable pore size (7.2 nm) and sheet thickness similar to 5-6 nm are realized in this first report. This elegant material possesses unique low band-gap energy (2.42 eV). Remarkably, the as-synthesized g-C(3)N(4.5)NSs exhibit a record high photocatalytic H(2)evolution rate of 8180 mu mol g(-1)h(-1)under the present light irradiation (420 &lt;=lambda &lt;= 510 nm) condition. The apparent quantum efficiency is found to be as high as 27.14% at 420 nm and retains its photocatalytic activity for longer consecutive catalytic cycles. Bigger pore size and pore volume, and thin walls leading to shortening of the path length of exciton pairs, efficient charge separation and the prolonged average life time of the charge carriers, and lone electron pairs associated with the excess nitrogen content are found to be the reasons behind the excellent visible light driven water splitting reaction.</p>
1 aAntil, Bindu1 aRanjan, Ravi1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/directed-holey-and-ordered-g-c3n45nanosheets-hard-template-nanocasting-approach-sustainable02731nas a2200277   4500008004100000022001400041245015700055210006900212260000900281300001400290490000600304520175500310653001902065653003002084653003202114653001802146653001802164100001702182700001902199700001702218700002302235700002202258700003002280700001802310856012502328       2021                        eng d  a2574-096200aOne-dimensional multichannel g-C3N4.7 nanostructure realizing an efficient photocatalytic hydrogen evolution reaction and its theoretical investigations0 aOnedimensional multichannel gC3N47 nanostructure realizing an ef  cAPR   a3118-31290 v43 a<p>The emerging metal-free carbon nitride (C3N4) offers prominent possibilities for realizing the highly effective hydrogen evolution reaction (HER). However, its poor surface conductivity and insufficient catalytic sites hinder the HER performance. Herein, a one-dimensional vermicular rope-like graphitic carbon nitride nanostructure is demonstrated that consists of multichannel tubular pores and high nitrogen content, which is fabricated through a cost-effective approach having the final stoichiometry g-C3N4.7 for HER application. The present g-C3N4.7 is unique owing to the presence of abundant channels for the diffusion process, modulated surface chemistry with rich- electroactive sites from N-electron lone pairs, greatly reduced recombination rate of photoexcited exciton pairs, and a high donor concentration (4.26 x 10(17) cm(3)). The catalyst offers a visible-light-driven photocatalytic H-2 evolution rate as high as 4910 mu mol h(-1)g(-1) with an apparent quantum yield of 14.07% at band gap absorption (2.59 eV, 479 nm) under 7.68 mW cm(-2) illumination. The number of hydrogen gas molecules produced is 1.307 x 10(15) s(-1) cm(-2), which remained constant for a minimum of 18 h of repeated cycling in the HER without any degradation of the catalyst. In density functional theory calculations, a significant change in the band offset is observed due to N doping into the system in favor of electron catalysis. The theoretical band gap of a monolayer of g-C3N4.7 was enormously reduced because of the presence of additional densities of states from the doped N atom inside the band gap. These impurity or donor bands are formed inside the band gap region, which ultimately enhance the hydrogen ion reduction reaction enormously.</p>10acarbon nitride10aDensity functional theory10ahydrogen evolution reaction10anitrogen-rich10aPhotocatalyst1 aAntil, Bindu1 aKumar, Lakshya1 aRanjan, Ravi1 aShenoy, Sulakshana1 aTarafder, Kartick1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/one-dimensional-multichannel-g-c3n47-nanostructure-realizing-efficient-photocatalytic