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[Display omitted] • Ag@ZnFe 2 O 4 -ZnO plasmonic nanohybrids were fabricated by facile wet chemical route. • Ag@ZnFe 2 O 4 -ZnO nanohybrids exhibited strong catalytic and photocatalytic performance. • Ag@ZnFe 2 O 4 -ZnO nanohybrids degraded MB, MG, MO and RhB in only 18 min. • Ag@ZnFe 2 O 4 -ZnO nanohybrids reduced 4-NP with high rate constant of 0.247 min−1. • Mechanisms of superior photocatalytic and catalytic performance of Ag@ZnFe 2 O 4 -ZnO nanohybrids are proposed. We report facile fabrication of magnetically separable Ag@ZnFe 2 O 4 -ZnO plasmonic hybrid nanostructures by a simple wet chemical route combined with cost-effective photodeposition. The successful formation of Ag@ZnFe 2 O 4 -ZnO hybrid nanostructures was confirmed using XRD, Raman, FESEM, TEM, HRTEM and SAED characterizations. The catalytic and photocatalytic capabilities of the synthesized magnetic Ag@ZnFe 2 O 4 -ZnO plasmonic hybrid nanostructures were evaluated with regard to 4-NP to 4-AP reduction in dark and photodecomposition of major anionic and cationic pollutants (MB, MG, MO, RhB) and emerging pollutant levofloxacin antibiotic under sunlight illumination, respectively. Results showed that Ag@ZnFe 2 O 4 -ZnO hybrid nanostructures exhibit excellent catalytic as well as photocatalytic response and reduced 98.1 % of 4-NP in only 6 min and decolorized 92.9, 93, 43.4 and 73.3 % of MB, MG, MO and RhB within only 18 min and 90.5 % of levofloxacin in 40 min of sun light irradiation, respectively. Further, the synthesized nanohybrids possess high stability and can be magnetically recovered due to its good magnetic response. In addition, the trapping experiments indicated that the main active compounds for the photodegradation of dyes are OH radicals. We demonstrate that the prepared Ag@ZnFe 2 O 4 -ZnO plasmonic hybrid nanostructures have potential application towards decomposition of organic pollutants and other emerging pollutants in wastewater for environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] Rare earth doping in ZnO is an efficient way to improve the photocatalytic performance. In the present work, Er doped ZnO nanospindles and nanorods were prepared through a simple cost effective wet chemical approach and were thoroughly characterized by FESEM, XRD, Raman spectroscopy, UV–vis-DRS, UV–vis absorption and PL spectroscopy. Nanospindle and nanorod-like morphologies of the fabricated samples were revealed by FESEM. XRD analyses revealed hexagonal wurtzite structure of Er doped ZnO nanostructures and confirmed Er doping into ZnO. PL studies showed increased defect concentration in ZnO nanostructures doped with Er ions. The photodegradation ability of nanostructures was investigated using cationic and anionic dyes and photodecomposition rate of 0.042 min−1 was achieved for MB decolorization using 0.5 % Er doped ZnO sample upon 32 min of solar light illumination. The probable photodecomposition mechanism supported by in-situ radical trapping experiments and repeatability test have also been discussed and results suggest that Er doped ZnO photocatalyst exhibit potential for use as commercial solar-active photocatalysts. [ABSTRACT FROM AUTHOR]

We report on the effects of 8 MeV Si 3+ ion irradiation on the structural, morphological and optical properties of nanostructured SnO 2 thin films, prepared by a simple thermal evaporation method. The structural and morphological evolution of nanostructured SnO 2 thin films upon MeV ion irradiation was studied by X-ray diffraction (XRD) and atomic force microscopy (AFM), while the optical properties of the thin films were characterized by Raman spectroscopy and photoluminescence spectroscopy (PL). XRD studies revealed the presence of nanocrystals of orthorhombic SnO 2 and cubic Sn in the as-deposited thin films. AFM studies revealed growth of SnO 2 nanoparticles in the films upon MeV ion irradiation. PL studies on the 8 MeV Si ion irradiated nanostructured SnO 2 thin films revealed strong enhancement in the intensity of UV and visible emissions from SnO 2 nanostructures. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ce doped ZnO-Au plasmonic nanorods were fabricated by simple thermal decomposition. • UV–vis DRS showed band gap decrease from 3.26 to 3.19 eV on Au decoration. • Ce doped ZnO-Au nanohybrids exhibited enhanced photocatalytic and catalytic performance. • Ce doped ZnO-Au nanohybrids degraded major pollutants in water in only 10 min. • Mechanism of extreme photocatalytic activity of Ce doped ZnO-Au nanohybrids is proposed. Plasmonic Au nanoparticles (NPs) have been deposited onto Ce doped ZnO nanorods prepared through wet chemical route to enhance their photodecomposition performance. The catalytic and photocatalytic performances were evaluated using a series of model pollutants such as 4-nitrophenol, antibiotic levofloxacin, cationic and anionic dyes under sunlight illumination. Various characterization tools such as XRD, Raman, FESEM, TEM, SAED, EDX, XPS, PL and UV–vis spectroscopy were used to examine the structure and physico-chemical properties of the fabricated photocatalysts. XRD, TEM, SAED, EDX, XPS and Raman analyses confirmed the existence of Ce doped ZnO and Au nanostructures while UV–visible absorption studies revealed the presence of SPR of Au NPs in the visible region. The results illustrated that decoration of Au NPs on Ce doped ZnO nanorods makes them outstanding catalyst as well as photocatalyst compared to pure Ce doped ZnO nanorods. The plasmonic nanohybrids with higher Au concentration exhibited superior degradation capability towards reduction and detoxification of 4-NP, decomposition of antibiotic levofloxacin and synthetic dyes, respectively. In addition, detailed study of possible mechanisms behind 4-NP reduction and photodegradation process have been explored. Furthermore, the quenching experiments elucidating · O 2 - radicals as the main active species in the degradation mechanism have also been discussed. Moreover, the prepared Ce doped ZnO-Au hybrid plasmonic nanorods maintained high stability and stunning photoactivity even after four cycles which highlights it as a promising material for wastewater treatment. [ABSTRACT FROM AUTHOR]

• Au/SnO 2 thin films were prepared by sputtering combined with thermal evaporation • FESEM and AFM studied revealed nanoparticles in the SnO 2 and Au/SnO 2 films. • Nanocrystalline SnO 2 , Au, Sn and Au-Sn alloy were revealed by XRD analysis. • PL studies revealed that Au decoration of SnO 2 film led to enhanced UV emission. We report significantly enhanced photoluminescence from hybrid nanostructured Au/SnO 2 thin films due to surface plasmons excited in Au nanoparticles decorating SnO 2 nanostructured thin film. Nanostructured thin films with Au nanoparticles decorated SnO 2 nanostructures were prepared by sputter deposition of ultrathin Au films following thermal evaporation of SnO 2 film. The effects of deposition of ultrathin film of Au nanoparticles on the morphology, structure and optical response of nanostructured SnO 2 film were investigated. Nanocrystalline SnO 2 , Au, Sn and Au-Sn alloy were revealed by XRD analysis. PL studies revealed that Au nanoparticle decoration of nanostructured SnO 2 film led to highly enhanced UV emission. The mechanism of strong enhancement of PL from nanostructured SnO 2 film is tentatively proposed. The coupling of excitonic emission from SnO 2 nanostructures and excited surface plasmons in Au nanoparticles led to the observed strong PL enhancement. The hybrid nanostructured Au/SnO 2 thin films with strong UV emission are promising for designing efficient optical and photoelectrical devices. [ABSTRACT FROM AUTHOR]

Ag–TiO 2 nanocomposite thin films on silica glass were prepared through thermal evaporation in combination with RF magnetron sputtering. Thermal annealing induced changes in the optical, morphological and structural properties of Ag–TiO 2 nanocomposites were examined using optical absorption, photoluminescence spectroscopy, Raman spectroscopy, FESEM, AFM and XRD. FESEM and AFM studies revealed cave in of the Ag–TiO 2 thin film at various places leading to the formation nanoscale pits upon thermal annealing at 600 °C. The computed average size of pits was found to be 54 nm. Raman studies indicated 600 °C annealing induced transformation of anatase phase of TiO 2 into anatase/rutile mixed phase TiO 2. Optical absorption spectra showed systematic changes due to the effects of mixed phase formation and variation in the plasmonic behavior upon annealing. PL results of the as deposited Ag–TiO 2 thin film showed peaks at 377, 402, 432 and 486 nm. PL studies of Ag–TiO 2 nanocomposites treated at different annealing temperatures revealed changes in defect concentration in TiO 2. The tentative mechanism for the creation of nanoscale pits in Ag–TiO 2 thin film through thermal annealing was proposed. [ABSTRACT FROM AUTHOR]

Abstract Thin films of Ag-TiO 2 plasmonic nanocomposites were fabricated on silica glass substrates by a combined approach using thermal evaporation and RF magnetron sputtering. The optical and plasmonic response of Ag-TiO 2 nanocomposites were tuned with the help of thermal annealing by varying the annealing temperature from 400 °C to 600 °C. The optical absorption spectra revealed the transformation of Ag nanolayer into Ag nanoparticles upon annealing. The band gap of Ag-TiO 2 nanocomposite thin films varied from 3.09 eV to 2.53 eV due to annealing. AFM studies revealed growth of nanostructures in the Ag-TiO 2 nanocomposites with increase in annealing temperature. The average nanoparticle size varied from 27 nm to 230 nm upon annealing. XRD results confirmed the appearance of Ag nanoparticles along with nanostructured anatase TiO 2. The photoluminescence spectra of Ag-TiO 2 nanocomposites revealed significant enhancement in intensity of UV and defect emissions upon annealing at 600 °C. The observed enhancement originated from the changes in the plasmonic properties of Ag nanostructures in the nanocomposite upon annealing. The observed significant enhancement in the UV emission arises due to the resonant coupling of surface plasmons of Ag nanoparticles with the band edge emission from TiO 2 which significantly improved the number of electrons in the conduction band of TiO 2. The PL enhancement in the visible region is ascribed to increased creation of shallow traps in TiO 2 due to the presence of Ag nanoparticles. This work provides a simple route to strong enhancement in PL intensity of nanostructured TiO 2 thin film which is very promising for applications in nanophotonics. Graphical abstract Image 1 Highlights • Ag-TiO 2 nanocomposites were prepared by RF magnetron sputtering and evaporation. • AFM revealed growth of nanostructures in the Ag-TiO 2 nanocomposite upon annealing. • PL of Ag-TiO 2 nanocomposite revealed intense peaks at 378, 401, 431 and 486 nm. • Annealing led to strong enhancement in UV and defect emissions from nanocomposite. [ABSTRACT FROM AUTHOR]

Abstract A facile low temperature wet chemical synthesis of ZnO nanosheets with tunable thickness is reported. Well defined ZnO nanosheets were obtained by simply varying the zinc precursor (zinc acetate, zinc sulphate and zinc nitrate). The effects of counter ions on the morphological, optical, structural and photocatalytic behavior of the synthesized ZnO nanosheets were investigated. Atomic force microscopy studies revealed appreciable changes in the morphology and significant decrease in the thickness (from 23 nm to 9.5 nm) of ZnO nanosheets as the counter ions were changed from acetate to sulphate ions. Photoluminescence spectroscopy and optical absorption studies showed that the counter ions appreciably affect the optical properties of the prepared nanosheets. The intensity of UV emissions from ZnO nanosheets followed the order of counter ions: acetate < sulphate < nitrate. Photocatalytic removal of methylene blue by the prepared ZnO nanosheets was also studied. The photocatalytic activity of ZnO nanosheets followed the order of counter ions: acetate > sulphate > nitrate. The origins of the observed subtle changes in the thickness and the variations in the optical, morphological and photocatalytic behavior of ZnO nanosheets with variation in the counter ions are tentatively proposed. [ABSTRACT FROM AUTHOR]

Hybrid nanostructured thin films of Au/SnO 2 consisting of SnO 2 nanostructures decorated with Au nanoparticles were synthesized by thermal evaporation of nanostructured SnO 2 thin films combined with deposition of ultrathin Au films by sputtering. The synthesized Au/SnO 2 hybrid nanostructured thin films were irradiated with 8 MeV Si 3+ ions at room temperature to fluences varying from 2 × 10 14 to 5 × 10 15 ions/cm 2 . Effects of MeV ion irradiation on the morphological, structural and optical properties of Au/SnO 2 hybrid nanostructured thin films were studied using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Raman spectroscopy, UV–Visible absorption spectroscopy and photoluminescence spectroscopy (PL). XRD studies revealed the presence of nanostructures of SnO 2 , Au, Sn and Au-Sn alloy in the as-deposited thin films. XRD and AFM studies showed growth in size of nanostructures in the Au/SnO 2 hybrid nanostructured thin films upon ion irradiation. PL studies on as-deposited Au/SnO 2 hybrid nanostructured thin film revealed intense peaks at 382, 399, 419, 455 and 542 nm. MeV ion irradiation resulted in strong enhancement in UV emission and visible emissions from SnO 2 nanostructures in the Au/SnO 2 hybrid nanostructured thin films. Gas sensing studies showed that the sensor prepared using Au/SnO 2 hybrid nanostructured thin film exhibits highly enhanced CO gas sensing properties as compared to pure SnO 2 nanostructured thin film sensor and shows excellent selectivity for CO gas with negligible interference from CH 4 , NH 3 , CO 2 and SO 2 . The mechanism underlying the enhanced gas sensing properties of Au/SnO 2 nanostructured thin film is tentatively proposed. [ABSTRACT FROM AUTHOR]

• ZnFe 2 O 4 /ZnO hybrid nanostructures were synthesized by facile co-precipitation. • ZnFe 2 O 4 /ZnO hybrid nanostructures exhibited excellent photocatalytic performance. • ZnFe 2 O 4 /ZnO hybrid nanostructures degraded organic pollutants in only 24 min. • Mechanism of superior photocatalytic activity of ZnFe 2 O 4 /ZnO nanostructures is proposed. [Display omitted] ZnFe 2 O 4 /ZnO heterojunction photocatalysts have been fabricated via simple co-precipitation method and systematically characterized. The structural and morphological analyses using XRD, Raman and FESEM confirmed the formation of ZnFe 2 O 4 /ZnO hybrid nanostructures. The optical properties were analysed via UV–vis DRS, PL and UV–vis absorption spectroscopy. UV–vis DRS studies showed band gap variation from 1.91 to 2.07 eV. The visible light-driven photodegradation activity of the synthesized products was explored by decomposing toxic pollutants in water and the results showed that ZnFe 2 O 4 /ZnO hybrid nanostructures exhibit superior photodegradation performance over pristine ZnFe 2 O 4 nanostructures. The improved photocatalytic performance of ZnFe 2 O 4 /ZnO nanostructures is ascribed to efficient sunlight utilization ability and suppression of recombination of photoinduced charge carriers due to p-n nanoheterojunction formation. In addition, photodegradation mechanism supported with scavenger experiments has been proposed. Besides the excellent photoactivity, ZnFe 2 O 4 /ZnO hybrid nanostructures are outstandingly stable, recyclable and thereby exhibit an enormous potential for large scale photocatalytic applications. [ABSTRACT FROM AUTHOR]

• CeO 2 nanodiscs were prepared by a template-free and surfactant-free wet chemical route. • FESEM and TEM studies revealed that CeO 2 nanodiscs consist of CeO 2 nanoparticles. • XRD and Raman studies showed crystallite size dependent variation in lattice strain and disorder. • PL studies revealed high concentration of Ce3+ and oxygen vacancies in CeO 2 nanodiscs. • CeO 2 nanodiscs with crystallite size of 8.2 nm exhibited superior photocatalytic activities. Nanodiscs of ceria (CeO 2) were prepared through a template-free and surfactant-free simple wet chemical method and were well characterized by TEM, FESEM, XRD, XPS, Raman, photoluminescence (PL) and UV–vis spectroscopy. The effects of crystallite size on the optical response and photocatalytic performance of CeO 2 nanodiscs were investigated. FESEM and TEM studies revealed that CeO 2 nanodiscs are made up of CeO 2 nanoparticles. XRD and Raman studies revealed crystallite size dependent variation in the lattice strain and disorder in the CeO 2 nanodiscs with cubic fluorite structure. PL studies revealed higher concentration of Ce3+ defects and oxygen vacancies in CeO 2 nanodiscs with smaller crystallite size. CeO 2 nanodiscs with crystallite size of 8.2 nm exhibited superior photocatalytic activities for solar degradation of MB, MG and MO. The mechanisms underlying formation of CeO 2 nanodiscs and their enhanced photocatalytic response were tentatively proposed. [ABSTRACT FROM AUTHOR]