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Abstract: Ho and Y doped ZnO nanoparticles were synthesized using a wet chemical route followed by structural, electrical and magnetic property characterization of the same. We present a comparison of the properties of Ho and Y (having same ionic radii) doped ZnO nanoparticles. X-ray diffraction studies of the diffraction data exhibit a monophasic wurtzite crystal structure similar to that of the parent compound, ZnO. Microstructural investigations of these samples by scanning electron microscopy show the presence of nanostructures. The optical measurements show an increase in the band gap of doped samples as compared to the undoped sample. DC magnetization measurements of Ho doped ZnO point towards the presence of hysteresis loop at 5K with an Hc of about 110Oe for a nominal 1mol% Ho doped sample. The resistivity of Ho doped sample is found to be higher as compared to the undoped and Y doped sample. [Copyright &y& Elsevier]

ZnO forks, brooms and spheres possessing self assembled nanowalls and nanocones of ZnO were synthesized, for the first time, via direct thermal evaporation of metallic Zn flakes. The samples exhibit visible green emission on UV excitation. EDX point towards oxygen deficient sample. Photoluminescence studies confirm the presence of defect related emission. The sharp nanocone tips and high degree of networking of nanowalls make them a potential candidate for field emission, gas sensing and catalytic applications. [Copyright &y& Elsevier]

In this paper we report on the preparation of nanobrushes of ZnO on quartz substrate by a direct atmosphere evaporation method using Zn metal flakes. Activated charcoal was used as a catalyst that facilitated the formation of nanobrushes in which the brush stem was about 15–20 μm in length and the bristles (100–200 nm thick) were made up of nanofibrous ZnO whose tips were 10–15 nm in width and were angled in some cases. These aligned nanobrushes can find potential applications as nanopower generators and high aspect ratio AFM probes by virtue of the piezoelectric property of ZnO. This technique is simple for realizing aligned ZnO nanobrushes with metallic Zn as the source material. [ABSTRACT FROM AUTHOR]

A novel UV–visible light active oxynitride photocatalyst, ZnO:InN, has been demostrated to exhibit efficient hydrogen evolution from water as compared to some conventional photocatalysts. A reduction in bandgap (2.82 eV), as estimated from diffuse reflectance spectra, is explained using Valence band XPS studies and attributed to the upshift in valence band maximum. Photocatalytic activity of the samples has been demonstrated by organic dye degradation, where 92% decay was observed in 180 min under direct sunlight. Photoelectrochemical studies under visible light showed significant photoresponse with a photocurrent density of ∼8 μA/cm2. This study, as per our knowledge, is first of its kind where ZnO:InN oxynitride has been explored as a UV–visible light active photocatalyst with significant H 2 generation of ∼48 μmol/g by UV–visible light water splitting using methanol scavenger. The results show the promising future applications of ZnO:InN oxynitride as a sunlight active photocatalyst for hydrogen production. • Synthesis of novel Zn 1-x In x O 1-y N y oxynitride photocatalyst for H 2 evolution. • Bandgap modification to 2.82 eV. • Methylene blue degradation upto 92% under direct sunlight. • Significant Photocurrent generation under UV–Vis irradiation. • Hydrogen evolution using Zn 1-x In x O 1-y N y oxynitride reported for first time. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel one-pot ultrarapid sonochemical synthesis technique is demonstrated. • Multi-component ZnO-Cu x -GO y hierarchical structures are fabricated. • Bandgap energy of ZnO-Cu 1.0 -GO 0.25 HSs decreased to 2.90 eV. • Ibuprofen was efficiently degraded using ZnO-Cu 1.0 -GO 0.25 HSs under visible light. • Synergistic effect of Cu doping and GO addition enhanced photocatalytic efficiency. Three-dimensional (3D) hierarchical structures (HSs) have demonstrated excellent properties for various applications that are attributable to their distinctive micro-sized architecture with nanoscale substructures. Recently, the ultrarapid sonochemical approach was found to be an effective strategy for synthesizing single component HSs with uniform morphologies in comparison to the direct precipitation technique. We here report the fabrication of copper doped zinc oxide grafted on graphene layers (ZnO-Cu x -GO y) for exploring the capability of this ultrarapid approach for synthesizing multi-component HSs. Interestingly, the morphology of ZnO-Cu x -GO y HSs studied through electron microscopy revealed the growth of ZnO HSs decorated with Cu nanoparticles and interconnected by graphene layers. ZnO-Cu x -GO y HSs demonstrated three-fold higher efficiency in the photodegradation of ibuprofen (IBU) under visible light irradiation in comparison to pristine ZnO HSs, which is attributable to the combined influence of the doped Cu2+ ions and graphene, enabling improved visible light absorption and inhibiting the recombination of photogenerated charges. Thus, the novel ultrarapid sonochemical synthesis strategy demonstrated here is anticipated to open up a new horizon for the time-saving and scalable design of multi-component HSs of various materials for a myriad of applications. [ABSTRACT FROM AUTHOR]