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781.
Visible Light Photocatalytic Activity of Pt/N‐TiO2 towards Enhanced H2 Production from Water Splitting 下载免费PDF全文
Present work mainly focuses on experimental investigation to improvement of hydrogen production by water photoelectrolysis. An experimental facility was designed and constructed for visible light photocatalysis. A series of N‐TiO2 photocatalysts impregnated with platinum on the surface of N‐TiO2 were prepared. Hydrogen production upon irradiating aqueous Pt/N‐TiO2 suspension with visible light was investigated. The shift in excitation wavelength of TiO2 was 380 nm improved the yield of hydrogen production by N‐TiO2 and Pt/N‐TiO2. We used a 400 W mercury arc lamp combined with a 400 nm cutoff filter eliminating all the wavelengths under 400 nm. Pt/N‐TiO2 material was characterized with TPR, reflective UV/Visible spectroscopy and TEM. The best hydrogen production rate obtained for this setup for N/Ti = 10, 0.05 wt% Pt/N‐TiO2, through water splitting was about 772 μmolh?1g?1. 相似文献
782.
First successful design of semi-IPN hydrogel-silver nanocomposites: a facile approach for antibacterial application 总被引:4,自引:0,他引:4
Murthy PS Murali Mohan Y Varaprasad K Sreedhar B Mohana Raju K 《Journal of colloid and interface science》2008,318(2):217-224
Semi-IPN hydrogels in which poly(vinyl pyrrolidone) (PVP) chains were physically dispersed throughout poly(acrylamide) (PAM) gel networks were synthesized. These semi-IPN hydrogel networks can act as excellent nanoreactors for producing and stabilizing metal nanoparticles. The current methodology allows us to entrap metal nanoparticles throughout hydrogel networks via PVP chains. An optimized semi-IPN hydrogel formulation was found to produce silver nanoparticles, ca. 3-5 nm. The synthesized semi-IPN hydrogel-silver nanocomposites were fully characterized by using UV-vis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The developed semi-IPN hydrogel-silver nanocomposite (SHSNC) was evaluated for preliminary antibacterial applications. 相似文献
783.
Mecomber JS Murthy RS Rajam S Singh PN Gudmundsdottir AD Limbach PA 《Langmuir : the ACS journal of surfaces and colloids》2008,24(7):3645-3653
Herein we report the topochemical modification of polymer surfaces with perfluorinated aromatic azides. The aryl azides, which have quaternary amine or aldehyde functional groups, were linked to the surface of the polymer by UV irradiation. The polymer substrates used in this study were cyclic olefin copolymer and poly(methyl methacrylate). These substrates were characterized before and after modification using reflection-absorption infrared spectroscopy, sessile water contact angle measurements, and X-ray photoelectron spectroscopy. Analysis of the surface confirmed the presence of aromatic groups with aldehyde or quaternary amine functionality. Enzyme immobilization and patterning onto polymer surfaces were studied using confocal microscopy. Enzymatic digests of protein were carried out on modified probes manufactured from thermoplastic substrates, and the resulting peptide analysis was completed using matrix-assisted laser desorption/ionization mass spectrometry. The use of functionalized perfluorinated aromatic azides allows the surface chemistry of thermoplastics to be tailored for specific lab-on-a-chip applications. 相似文献
784.
Ultra-fine (<1 microm) microfilters are required to effectively trap microbial cells. We designed microfilters featuring a rain drop bypass architecture, which significantly reduces the likelihood of clogging at the cost of limited cell loss. The new rain drop bypass architecture configuration has a substantially lower pressure drop and allows a better efficiency in trapping protozoan cells (Cryptosporidium parvum and Giardia lamblia) in comparison to our previous generation of a microfilter device. A modified version displaying sub-micron filter gaps was adapted to trap and detect bacterial cells (Escherichia coli), through a method of cells labeling, which aims to amplify the fluorescence signal emission and therefore the sensitivity of detection. 相似文献
785.
A systematic study has been carried out on the effects of interface bonding on the strain mediated magnetoelectric (ME) coupling in ferromagnetic-ferroelectric bilayers. The technique used involves the static electric field E tuning of the ferromagnetic resonance (FMR) in yttrium iron garnet (YIG) and lead zirconate titanate (PZT) or lead magnesium niobate-lead titanate (PMN-PT). A broad band detection technique has been developed for studies over 1?C40 GHz in three types of bilayers: epoxy bonded, eutectic bonded and YIG films directly grown onto piezoelectric substrate by electrophoretic deposition. The strength A of the converse ME effect (CME) defined as the ratio of the frequency shift ??f in FMR in E, A = ??f/E, varies over the range 0.8 to 4.3 MHz??cm/kV, and is the highest for eutectic bonded samples and is the weakest for epoxy bonded bilayers. The results presented here as of importance for dual electric and magnetic field tunable ferrite-ferroelectric microwave resonators and filters. 相似文献
786.
Santosh Kumar Mohammad Changez C. N. Murthy Shigeru Yamago Jae‐Suk Lee 《Macromolecular rapid communications》2011,32(19):1576-1582
Low‐molecular weight amphiphilic diblock copolymers, polystyrene‐block‐poly (2‐vinylpyridine) (PS‐b‐P2VP), and (P2VP‐b‐PS) with different block ratios were synthesized for the first time via organotellurium‐mediated living radical polymerization (TERP). For both the homo‐ and block copolymerizations, good agreement between the theoretical, and experimental molecular weights was found with nearly 100% yield in every case. The molecular weight distribution for all the samples ranged between 1.10 and 1.24, which is well below the theoretical lower limit of 1.50 for a conventional free radical polymerization. Furthermore, a very simple approach to producing highly dense arrays of titania nanoparticles (TiO2) is presented using a site‐selective reaction of titanium tetraisopropoxide within the P2VP domains of micellar film of P2VP‐b‐PS in toluene through the sol–gel method.
787.
Nilam L. Chauhan Jagannath Das Raksh V. Jasra Z. V. P. Murthy Parimal A. Parikh 《Crystal Research and Technology》2012,47(7):746-753
Zeolite ZSM‐5 has been synthesized in presence of various emulsifiers. Influence of types and proportions of cationic, anionic and non‐ionic emulsifier has been studied. Cationic emulsifier, cetyl trimethyl ammonium bromide resulted in an amorphous phase, whereas anionic emuisifier, sodium lauryl sulphate afforded crystalline phase, identified as magadiite. Non‐ionic emulsifiers, 1,2,3‐benzotriazole and sorbital mono‐stearate led to the formation of pure crystalline ZSM‐5 phase. Emulsifier concentration was found to affect the process of crystallization, and the crystal size and morphology of ZSM‐5. Emulsifier necessitated higher crystallization temperature and/or longer hydrothermal period. ZSM‐5 crystallization was observed to proceed through magadiite phase formation. In case of benzotriazole, unusual stacked square platelet type morphology and with sorbital monostearate, very small crystals were observed. 相似文献
788.
We have developed a pragmatic route to the stereogenic skipped 1,3,5-polyols. The strategic transformation includes an organocatalytic enantioselective asymmetric epoxidation, which is either syn- or anti-selective as genesis of chirality and successive SN2 opening reaction by an appropriate functionalized nucleophile, followed by hydroboration/oxidation to generate stereoisomers in good yield. The critical intermediate generated en route to this process is employed in the total synthesis of polyrhacitide A. 相似文献
789.
K. RameshS. Narayana Murthy K. KarnakarY.V.D. Nageswar Kukuma VijayalakhshmiBethala L.A. Prabhavathi Devi R.B.N. Prasad 《Tetrahedron letters》2012,53(9):1126-1129
The new bioglycerol-based carbon catalyst acts as an efficient, readily available, and reusable catalyst for the synthesis of 2,4,5-trisubstituted imidazoles/1,2,4,5-tetrasubstituted imidazoles, when aromatic aldehyde, ammonium acetate/amine, and 1,2-diketone are reacted in acetonitrile. 相似文献
790.
Karnakar Konkala Narayana Murthy Sabbavarapu Ramesh Katla Nageswar Yadavalli Venkata Durga Vijai Kumar Reddy T 《Tetrahedron letters》2012,53(15):1968-1973
A simple and efficient synthetic protocol has been developed for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones by using a novel bioglycerol-based sulfonic acid functionalized carbon catalyst, devoid of moisture sensitive metal catalysts and corrosive acidic reagents. The developed method has the advantages of good to excellent yields, short reaction times, operational simplicity, and a recyclable catalyst. The catalyst can be prepared by a simple procedure from inexpensive and readily available glycerol and has been shown to be recoverable and reusable up to four cycles without any loss of activity. 相似文献