@article { ISI:000252511300009, title = {Low temperature synthesis of magnetite and maghemite nanoparticles}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {7}, number = {12}, year = {2007}, month = {DEC}, pages = {4294-4302}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

We report on the synthesis of iron oxide nanoparticles below 100 degrees C by a simple chemical protocol. The uniqueness of the method lies in the use of Ferrous ammoniurn sulphate (in conjugation with FeCl3) which helps maintain the stability of Fe-2+ state in the reaction sequence thereby controlling the phase formation. Hexamine was added as the stabilizer. The nanoparticles synthesized at three different temperatures viz, 5 degrees, 27 degrees, and 95 degrees C are characterized by several techniques. Generally, when a mixture of Fe3+ and Fe2+ is added to sodium hydroxide, alpha-Fe2O3 (the anti-ferromagnetic phase) is formed after the dehydration process of the hydroxide. In our case however, the phases formed at all the three temperatures were found to be ferro (ferri) magnetic, implying modification of the formation chemistry due to the specifics of our method. The nanoparticles synthesized at the lowest temperature exhibit magnetite phase, while increase in growth temperature to 95 degrees C leads to the maghemite phase.

}, keywords = {low temperature synthesis, maghemite, magnetite, Nanoparticles}, issn = {1533-4880}, doi = {10.1166/jnn.2007.873}, author = {Bhagwat, Shrikant and Singh, Hema and Athawale, Anjali and Hannoyer, Beatrice and Jouen, Samuel and Lefez, Benoit and Kundaliya, Darshan and Pasricha, Renu and Kulkarni, Shailaja and Ogale, Satishchandra B.} } @article { ISI:000275706100023, title = {Elucidation of the role of hexamine and other precursors in the formation of magnetite nanorods and their stoichiometry}, journal = {Physical Chemistry Chemical Physics}, volume = {12}, number = {13}, year = {2010}, month = {FEB}, pages = {3246-3253}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Hexamine is known to assist anisotropic growth of metal oxides and the same is also found to be true for magnetite nanosynthesis. In this work we elucidate the role of hexamine and other precursors in the formation of magnetite nanorods by the hydrothermal route and their stoichiometry. Various others hydrolyzing agents such as sodium hydroxide (NaOH), sodium hydroxide + hexamine, ammonia (NH(3)), ammonia + formaldehyde are also studied. The synthesized nanoparticles are characterized with the help of various techniques such as X-ray diffraction (XRD), FT-IR spectroscopy, UV-VIS-NIR spectroscopy, transmission electron microscopy (TEM), Mossbauer spectroscopy and SQUID magnetization measurements. It is found that only when ferric chloride, ferrous ammonium sulfate (FAS) and hexamine are used, well defined nanorods are formed. When sodium hydroxide and hexamine are used as a hydrolyzing system nearly spherical nanoparticles with small size (similar to 13 nm) are formed, as compared to the case of sodium hydroxide alone which leads to bigger cube like nanoparticles. Interestingly the decomposition products of hexamine do not lead to nanorod formation. Thus, slow decomposition of hexamine at elevated temperature and the consequent slow rise in pH is the key to the anisotropic growth of the iron oxide system.

}, issn = {1463-9076}, doi = {10.1039/b917407a}, author = {Singh, Hema and Bhagwat, Shrikant and Jouen, Samuel and Lefez, Benoit and Athawale, Anjali A. and Hannoyer, Beatrice and Ogale, Satishchandra} } @article { ISI:000293518300007, title = {From graphite oxide to highly water dispersible functionalized graphene by single step plant extract-induced deoxygenation}, journal = {Green Chemistry}, volume = {13}, number = {8}, year = {2011}, month = {JUL}, pages = {1990-1996}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

We report a single step facile synthesis of highly water dispersible functionalized graphene nanosheets by plant extract-induced deoxygenation of graphite oxide (GO). The results of various characterizations reveal that the properties of such plant extract-converted graphene nanosheets (PCGN) are comparable to chemically converted graphene nanosheets (CCG). These results open a green route to the emerging graphene-based technologies.

}, issn = {1463-9262}, doi = {10.1039/c1gc15393e}, author = {Mhamane, Dattakumar and Ramadan, Wegdan and Fawzy, Manal and Rana, Abhimanyu and Dubey, Megha and Rode, Chandrashekhar and Lefez, Benoit and Hannoyer, Beatrice and Ogale, Satishchandra} } @article { ISI:000293175800026, title = {Maghemite (hematite) core (shell) nanorods via thermolysis of a molecular solid of Fe-complex}, journal = {Dalton Transactions}, volume = {40}, number = {31}, year = {2011}, month = {2011}, pages = {8003-8011}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

An Fe-metal complex with 2{\textquoteright}-hydroxy chalcone (2{\textquoteright}-HC) ligands [Fe(III) (2{\textquoteright}-hydroxy chalcone) 3] is synthesized by a chemical route and is subjected to different thermal treatments. Upon thermolysis in air at 450 degrees C for 3 h the complex yields maghemite (gamma-Fe(2)O(3)) nanorods with a thin hematite (alpha-Fe(2)O(3)) shell. X-Ray diffraction (XRD), Mossbauer spectroscopy, diffuse reflectance spectroscopy (UV-DRS), high resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometry (VSM) are used to characterize the samples. The stability of the ligand and the Fe-complex is further examined by using thermogravimmetric/differential thermal analysis (TGA/DTA). We suggest a residual ligand controlled mechanism for the formation of an anisotropic nanostructure in a crumbling molecular solid undergoing ligand decomposition. Since the band gap of iron oxide is in the visible range, we explored the use of our core shell nano-rod sample for photocatalytic activity for H(2) generation by H(2)S splitting under solar light. We observed high photocatalytic activity for hydrogen generation (75 ml h(-1)).

}, issn = {1477-9226}, doi = {10.1039/c1dt10319a}, author = {Chaudhari, N. S. and Warule, S. S. and Muduli, Subas and Kale, B. B. and Jouen, Samuel and Lefez, Benoit and Hannoyer, Beatrice and Ogale, Satishchandra B.} } @article { ISI:000289518000002, title = {Magnetite/CdTe magnetic-fluorescent composite nanosystem for magnetic separation and bio-imaging}, journal = {Nanotechnology}, volume = {22}, number = {22}, year = {2011}, month = {JUN}, pages = {Article No. 225101}, publisher = {IOP PUBLISHING LTD}, type = {Article}, address = {TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND}, abstract = {

A new synthesis protocol is described to obtain a CdTe decorated magnetite bifunctional nanosystem via dodecylamine (DDA) as cross linker. High resolution transmission electron microscopy (HRTEM), energy-dispersive x-ray spectroscopy (EDAX), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and fluorescence microscopy are used to characterize the constitution, size, composition and physical properties of these superparamagnetic-fluorescent nanoparticles. These CdTe decorated magnetite nanoparticles were then functionalized with anti-epidermal growth factor receptor (EGFR) antibody to specifically target cells expressing this receptor. The EGFR is a transmembrane glycoprotein and is expressed on tumor cells from different tissue origins including human leukemic cell line Molt-4 cells. The magnetite-CdTe composite nanosystem is shown to perform excellently for specific selection, magnetic separation and fluorescent detection of EGFR positive Molt-4 cells from a mixed population. Flow cytometry and confocal laser scanning microscopy results show that this composite nanosystem has great potential in antibody functionalized magnetic separation and imaging of cells using cell surface receptor antibody.

}, issn = {0957-4484}, doi = {10.1088/0957-4484/22/22/225101}, author = {Kale, Anup and Kale, Sonia and Yadav, Prasad and Gholap, Haribhau and Pasricha, Renu and Jog, Jyoti Prakash and Lefez, Benoit and Hannoyer, Beatrice and Shastry, Padma and Ogale, Satishchandra B.} } @article { ISI:000305831300031, title = {From small aromatic molecules to functional nanostructured carbon by pulsed laser-induced photochemical stitching}, journal = {AIP Advances}, volume = {2}, number = {2}, year = {2012}, month = {JUN}, pages = {Article No. 022130}, publisher = {AMER INST PHYSICS}, type = {Article}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

A novel route employing UV laser pulses (KrF Excimer, 248 nm) to cleave small aromatic molecules and stitch the generated free radicals into functional nanostructured forms of carbon is introduced. The process differs distinctly from any strategies wherein the aromatic rings are broken in the primary process. It is demonstrated that this pulsed laser-induced photochemical stitching (PLPS) process when applied to routine laboratory solvents (or toxic chemical wastes when discarded) Chlorobenzene and o-Dichlorobenzene yields Carbon Nanospheres (CNSs) comprising of graphene-like sheets assembled in onion-like configurations. This room temperature process implemented under normal laboratory conditions is versatile and clearly applicable to the whole family of haloaromatic compounds without and with additions of precursors or other nanomaterials. We further bring out its applicability for synthesis of metal-oxide based carbon nanocomposites. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4721268]

}, issn = {2158-3226}, doi = {10.1063/1.4721268}, author = {Gokhale, R. R. and Thakare, V. P. and Warule, S. and Lefez, Benoit and Hannoyer, Beatrice and Jog, Jyoti Prakash and Ogale, S. B.} } @article { ISI:000310940500009, title = {Laser synthesized super-hydrophobic conducting carbon with broccoli-type morphology as a counter-electrode for dye sensitized solar cells}, journal = {Nanoscale}, volume = {4}, number = {21}, year = {2012}, month = {NOV}, pages = {6730-6734}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1\% as opposed to 6.2\% obtained with the conventional Pt-based electrode.

}, issn = {2040-3364}, doi = {10.1039/c2nr32082g}, author = {Gokhale, Rohan and Agarkar, Shruti A. and Debgupta, Joyashish and Shinde, Deodatta and Lefez, Benoit and Banerjee, Abhik and Jog, Jyoti Prakash and More, Mahendra A. and Hannoyer, Beatrice and Ogale, Satishchandra B.} } @article { ISI:000308099900044, title = {MOF derived porous carbon-Fe3O4 nanocomposite as a high performance, recyclable environmental superadsorbent}, journal = {Journal of Materials Chemistry}, volume = {22}, number = {37}, year = {2012}, month = {JUN}, pages = {19694-19699}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

A high surface area carbon composite with Fe3O4 nanoparticles is synthesized by pyrolysis of an iron containing Metal Organic Framework (MOF). The composite can be prepared by annealing the MOF at different temperatures (500 degrees C and 600 degrees C), each case exhibiting unique properties in terms of the hydrophobic behaviour and surface area, resulting in specific applicability domains. We highlight the exceptional behaviour of this material as a magnetically separable and recyclable superadsorbent for removal and recovery of environmental pollutants (oil/hydrocarbon and dye/phenol).

}, issn = {0959-9428}, doi = {10.1039/c2jm33798c}, author = {Banerjee, Abhik and Gokhale, Rohan and Bhatnagar, Sumit and Jog, Jyoti Prakash and Bhardwaj, Monika and Lefez, Benoit and Hannoyer, Beatrice and Ogale, Satishchandra B.} }