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Singh S.,University of Delhi | Pendurthi R.,Amity University | Khanuja M.,Jamia Millia Islamia University | Islam S.S.,Jamia Millia Islamia University | And 2 more authors.
Applied Physics A: Materials Science and Processing | Year: 2017

The amount of dopant concentration, alongwith the choice of dopant, is one of the most conducive factor for the favourable outcome for light driven activities of a material. The present paper reports on the synthesis of zinc oxide nanorods doped with different concentrations of copper (Cu–ZnO) by simple, low-cost mechanical assisted thermal decomposition process. The as synthesized samples were tested for visible light driven photo-electrochemical (PEC) and photocatalytic activities on various hazardous dyes using methylene blue (MB), methyl orange and mixed green dye (methyl thymol blue + methylene blue). The study helped us to reveal that highest degradation efficiency was achieved for Cu concentration of 5% in ZnO on MB (91.1% degradation in 40 min). Compared to pure ZnO, the photoactivity of 5% Cu–ZnO composites shows higher photodegradation of dyes. Moreover, the photocatalytic results were found consistent with PEC studies which showed maximum current generation of +9.4 mA for 5% Cu–ZnO (carried out under dark and illumination condition). The mechanism for this enhanced photoactivity has been proposed based on the relationship established between oxygen vacancies and defects generation in the material due to different doping concentrations that directly influence its photocatalytic efficiency. © 2017, Springer-Verlag Berlin Heidelberg.


Rao K.V.,Jawaharlal Nehru Centre for Advanced Scientific Research | Jalani K.,Jawaharlal Nehru Centre for Advanced Scientific Research | Jayaramulu K.,Chemistry and Physics of Materials Unit CPMU | Mogera U.,CPMU | And 2 more authors.
Asian Journal of Organic Chemistry | Year: 2014

Charge-transfer (CT) assemblies with mixed-stack (MS) arrays of donor (D) and acceptor (A) molecules are important class of functional organic materials owing to their interesting optoelectronic properties. Construction of charge-transfer nanostructures comprising cofacially stacked perylene/tetrathiafulvalene (TTF) donors and viologen acceptors by an efficient, noncovalent, amphiphilic approach is described. Optical properties were used to probe the CT coassembly and stoichiometry of molecular D/A components, whereas 1HNMR and X-ray diffraction studies provided insights into their face-to-face organization. The efficient equimolar coassembly between ionic D (perylene salt (PS) and TTF salt (TTFS)) and A (dodecylmethyl viologen (DMV) and hexadecylmethyl viologen (HDMV)) molecules in water through ground state CT interactions results in the formation of noncovalent amphiphiles. Microscopic studies provided structural insight into the hierarchical organization of these charge-transfer D-A amphiphiles into bilayers and one-dimensional nanostructures. In addition, at higher concentrations PS-HDMV amphiphiles form hydrogels due to strong hydrophobic interactions caused by the long hydrocarbon tails. Two probe devices fabricated from these CT nanostructures as channel elements showed impressive conductivity values without any external doping, thus validating the CT design for conducting organic wires. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Suresh V.M.,Chemistry and Physics of Materials Unit CPMU | Bandyopadhyay A.,New Chemistry Unit NCU | Roy S.,Chemistry and Physics of Materials Unit CPMU | Pati S.K.,Jawaharlal Nehru Centre for Advanced Scientific Research | Maji T.K.,Chemistry and Physics of Materials Unit CPMU
Chemistry (Weinheim an der Bergstrasse, Germany) | Year: 2015

Reversible and selective capture/detection of F(-) ions in water is of the utmost importance, as excess intake leads to adverse effects on human health. Highly robust Lewis acidic luminescent porous organic materials have potential for efficient sequestration and detection of F(-) ions. Herein, the rational design and synthesis of a boron-based, Lewis acidic microporous organic polymer (BMOP) derived from tris(4-bromo-2,3,5,6-tetramethylphenyl)boron nodes and diethynylbiphenyl linkers with a pore size of 1.08 nm for selective turn-on sensing and capture of F(-) ion are reported. The presence of a vacant pπ orbital on the boron center of BMOP results in intramolecular charge transfer (ICT) from the linker to boron. BMOP shows selective turn-on blue emission for F(-) ions in aqueous mixtures with a detection limit of 2.6 μM. Strong B-F interactions facilitate rapid sequestration of F(-) by BMOP. The ICT emission of BMOP can be reversibly regenerated by addition of an excess of water, and the polymer can be reused several times. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Suresh V.M.,Chemistry and Physics of Materials Unit CPMU | Bandyopadhyay A.,New Chemistry Unit NCU | Roy S.,Chemistry and Physics of Materials Unit CPMU | Pati S.K.,Jawaharlal Nehru Centre for Advanced Scientific Research | Maji T.K.,Chemistry and Physics of Materials Unit CPMU
Chemistry - A European Journal | Year: 2015

Reversible and selective capture/detection of F- ions in water is of the utmost importance, as excess intake leads to adverse effects on human health. Highly robust Lewis acidic luminescent porous organic materials have potential for efficient sequestration and detection of F- ions. Herein, the rational design and synthesis of a boron-based, Lewis acidic microporous organic polymer (BMOP) derived from tris(4-bromo-2,3,5,6-tetramethylphenyl)boron nodes and diethynylbiphenyl linkers with a pore size of 1.08 nm for selective turn-on sensing and capture of F- ion are reported. The presence of a vacant pπ orbital on the boron center of BMOP results in intramolecular charge transfer (ICT) from the linker to boron. BMOP shows selective turn-on blue emission for F- ions in aqueous mixtures with a detection limit of 2.6 μM. Strong B-F interactions facilitate rapid sequestration of F- by BMOP. The ICT emission of BMOP can be reversibly regenerated by addition of an excess of water, and the polymer can be reused several times. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


PubMed | Chemistry and Physics of Materials Unit CPMU, Jawaharlal Nehru Centre for Advanced Scientific Research and New Chemistry Unit NCU
Type: Journal Article | Journal: Chemistry (Weinheim an der Bergstrasse, Germany) | Year: 2015

Reversible and selective capture/detection of F(-) ions in water is of the utmost importance, as excess intake leads to adverse effects on human health. Highly robust Lewis acidic luminescent porous organic materials have potential for efficient sequestration and detection of F(-) ions. Herein, the rational design and synthesis of a boron-based, Lewis acidic microporous organic polymer (BMOP) derived from tris(4-bromo-2,3,5,6-tetramethylphenyl)boron nodes and diethynylbiphenyl linkers with a pore size of 1.08nm for selective turn-on sensing and capture of F(-) ion are reported. The presence of a vacant p orbital on the boron center of BMOP results in intramolecular charge transfer (ICT) from the linker to boron. BMOP shows selective turn-on blue emission for F(-) ions in aqueous mixtures with a detection limit of 2.6M. Strong B-F interactions facilitate rapid sequestration of F(-) by BMOP. The ICT emission of BMOP can be reversibly regenerated by addition of an excess of water, and the polymer can be reused several times.

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