Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Neha Bhardwaj,
• Jaspal Singh,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2013, 4, 763–770, doi:10.3762/bjnano.4.87

• UV–vis absorption spectroscopy. SEM and TEM studies revealed flower-like structures consisting of nanosheets, formed due to oriented attachment of ZnO nanoparticles. Flower-like ZnO structures showed enhanced photocatalytic activity towards sun-light driven photodegradation of methylene blue dye (MB

• ) as compared to ZnO nanoparticles. XRD, UV–vis absorption, PL, FTIR and TEM studies revealed the formation of Zn(OH)2 surface layer on ZnO nanostructures upon ageing. We demonstrate that the formation of a passivating Zn(OH)2 surface layer on the ZnO nanostructures upon ageing deteriorates their

• (MB) in 60 min. ZnO nanoparticles (NP) that were synthesized by wet chemical methods can be passivated by a Zn(OH)2 layer during ageing. Hong et al. [35] have shown that the photocatalytic activity of ZnO NP is drastically reduced when the is surface modified with polysterene. In this paper, we have

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

• Tanujjal Bora,
• Karthik K. Lakshman,
• Soumik Sarkar,
• Abhinandan Makhal,
• Samim Sardar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2013, 4, 714–725, doi:10.3762/bjnano.4.81

• 10.3762/bjnano.4.81 Abstract In recent years, nanotechnology has gained significant interest for applications in the medical field. In this regard, a utilization of the ZnO nanoparticles for the efficient degradation of bilirubin (BR) through photocatalysis was explored. BR is a water insoluble byproduct

• of the heme catabolism that can cause jaundice when its excretion is impaired. The photocatalytic degradation of BR activated by ZnO nanoparticles through a non-radiative energy transfer pathway can be influenced by the surface defect-states (mainly the oxygen vacancies) of the catalyst nanoparticles

• . These were modulated by applying a simple annealing in an oxygen-rich atmosphere. The mechanism of the energy transfer process between the ZnO nanoparticles and the BR molecules adsorbed at the surface was studied by using steady-state and picosecond-resolved fluorescence spectroscopy. A correlation of

Ferromagnetic behaviour of Fe-doped ZnO nanograined films

• Boris B. Straumal,
• Svetlana G. Protasova,
• Andrei A. Mazilkin,
• Thomas Tietze,
• Eberhard Goering,
• Gisela Schütz,
• Petr B. Straumal and
• Brigitte Baretzky

Beilstein J. Nanotechnol. 2013, 4, 361–369, doi:10.3762/bjnano.4.42

• . Moreover, it is specifically the grain boundaries and not the free surfaces that are crucial for FM behaviour. For example, it has been observed that the nonsintered ZnO nanoparticles doped with 16 atom % Co obtained by forced hydrolysis were not ferromagnetic [67]. This was despite the fact that their

Paper modified with ZnO nanorods – antimicrobial studies

• Mayuree Jaisai,
• Sunandan Baruah and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2012, 3, 684–691, doi:10.3762/bjnano.3.78

• in cellular internalization of ZnO nanoparticles has also been observed by Appierot et al. [6] in a study of their antibacterial effect on E. coli and S. aureus. This work reports on an antimicrobial paper containing zinc oxide (ZnO) nanorods grown by a hydrothermal process, and which can be used for

• and H2O2 are harmful to the cells of living organisms and are the major contributors to antibacterial activity [11][12][13]. ZnO nanoparticles are reported to have significant antifungal properties against B. cinerea and P. expansum, and the inhibitory effects were found to increase with an increase

• grown on glass substrates [25]. The proper attachment of the ZnO nanorods to the paper is crucial for commercial applications. Cellulose, the major ingredient of softwood pulp, is a long-chain polymer with hydroxyl groups that can form hydrogen bonds with the surface oxygen atoms of ZnO nanoparticles

Functionalised zinc oxide nanowire gas sensors: Enhanced NO₂ gas sensor response by chemical modification of nanowire surfaces

• Eric R. Waclawik,
• Jin Chang,
• Andrea Ponzoni,
• Isabella Concina,
• Dario Zappa,
• Elisabetta Comini,
• Nunzio Motta,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2012, 3, 368–377, doi:10.3762/bjnano.3.43

• (THMA) and dodecanethiol (DT), was studied. The response towards ammonia, nitrous oxide and nitrogen dioxide was investigated for three sensor configurations, namely pure ZnO nanowires, organic-coated ZnO nanowires and ZnO nanowires covered with a sparse layer of organic-coated ZnO nanoparticles

• response to NO2 compared to uncoated ZnO nanowire sensors. At the lower concentration levels tested, ZnO nanowire sensors that were coated with THMA-capped ZnO nanoparticles were found to exhibit the greatest enhanced response. ΔR/R was two times greater than that for the as-prepared ZnO nanowire sensors

• . It is proposed that the ΔR/R enhancement in this case originates from the changes induced in the depletion-layer width of the ZnO nanoparticles that bridge ZnO nanowires resulting from THMA ligand binding to the surface of the particle coating. The heightened response and selectivity to the NO2

Formation of SiC nanoparticles in an atmospheric microwave plasma

• Martin Vennekamp,
• Ingolf Bauer,
• Matthias Groh,
• Evgeni Sperling,
• Susanne Ueberlein,
• Maksym Myndyk,
• Gerrit Mäder and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 665–673, doi:10.3762/bjnano.2.71

• have been reported on this synthesis. Wiggers et al. investigated the formation of ZnO nanoparticles in a low-pressure microwave reactor by particle mass spectroscopy (PMS) [10]. In that work, about twenty one-factor-at-a-time experiments were evaluated, and a positive impact of the precursor

Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods

• Sunandan Baruah,
• Mohammad Abbas Mahmood,
• Myo Tay Zar Myint,
• Tanujjal Bora and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2010, 1, 14–20, doi:10.3762/bjnano.1.3

• observed with engineered defects in ZnO crystals achieved by fast crystallization during synthesis of the nanoparticles [20]. Results from photocatalysis experiments carried out using ZnO nanoparticles prepared through a slow growth process (3 h hydrolysis at 60 °C) and rapid crystallization (7 min under

• in the molecules adsorbed on the surface of defect engineered nanoparticles [21]. Upon excitation of ZnO nanoparticles with high-energy laser pulses at 375 nm in the presence of MB molecules, a quick decay in photoluminescence in the fast-crystallized particulate samples as compared to the

• conventionally hydrolyzed ones was observed. The spectroscopic results support the observation that surface defect states are created when the ZnO crystals are grown rapidly, which facilitates surface reactions such as photocatalysis. Even though the ZnO nanoparticles could efficiently carry out photocatalytic