Antibiotic water contamination is a growing environmental problem in the present day. As a result, water treatment is required for its reduction and elimination. Due to their important role in resolving this issue, photocatalysts have drawn a great deal of interest over the past few decades. When non-biodegradable organic matter is present in polluted water, the photo catalytic process, which is both environmentally friendly and an improved oxidation method, can be an effective means of remediation. In this regard, we report the successful synthesis of pure phased rare earth doped ZnO nanoparticles for tetracycline degradation. The prepared catalysts were systematically characterized for structural, optical, and magnetic properties. The optical band gap was tailored by rare earth doping, with redshift for Sm and Dy doped nanoparticles and blueshift for Nd doped ZnO nanoparticles. The analysis of photoluminescence spectra revealed information about the defect chemistry of all synthesised nanoparticles. Magnetic studies revealed that all synthesized diluted magnetic semiconductors exhibit room temperature ferromagnetism and can be employed for spintronic applications. Moreover, Dy doped ZnO nanoparticles were found to exhibit a maximum degradation efficiency of 74.19% for tetracycline (TCN) removal. The synthesized catalysts were also employed for the degradation of Malachite green (MG), and Crystal violet (CV) dyes. The maximum degradation efficiency achieved was 97.18% for MG and 98% for CV for Dy doped ZnO nanoparticles. The degradation mechanism involved has been discussed in view of the reactive species determined from scavenging experiments.

A palladium nanoparticle-decorated MoS₂ layered structure for the efficient oxygen evolution reaction.

The ion-beam-shaping mechanism is studied for several classes of nearly monodispersed metallic nanoparticles (Au, Ag, and Au${}_{0.5}$Ag${}_{0.5}$). They are in the range of 3–100 nm and embedded within a silica matrix. Experimentally, we show that depending on their initial sizes, several final morphologies can be obtained: (i) spherical shapes, (ii) facetted nanoparticles, (iii) nanorods, and (iv) nanowires. In parallel, the thermal-spike model was implemented for three-dimensional anisotropic and composite media to study the evolution of the temperature profile within a nanoparticle. This way, a clear correlation is found between the deformation path followed by the nanoparticles during the irradiation and the fraction of the nanoparticle that is molten (vaporized) due to the interaction with a swift heavy ion. This allows the construction of a size-vs-shape diagram relating the initial nanoparticle size to its final morphology. This diagram is used to give a rational description of the ion-beam-shaping process for all nanoparticle dimensions as a function of the irradiation parameters. DOI: http://dx.doi.org/10.1103/PhysRevB.86.035450 ©2012 American Physical Society

Irradiation with swift heavy ions of spherical Au nanoparticles confined within a silica matrix shapes them into prolate nanorods and nanowires whose principal axes are aligned along the beam direction. In the present paper, we investigate the role that is played by the initial nanoparticle size and concentration in this so-called ion-shaping mechanism. We have produced silica films wherein Au nanoparticles with average diameters of 15, 30, and 45 nm were embedded within a single plane and have irradiated these films at 300 K at normal incidence with 18, 25, and 54 MeV Ag ions. We demonstrate the existence of both threshold and saturation fluences for the elongation effects mentioned. The values of these critical fluences depend both on the ion energy and the initial nanoparticle size. Moreover, we show that 45 nm Au particles are not deformed when irradiated with 18 MeV Ag ions, such that this value corresponds to an energy threshold for the deformation process. As far as the influence of the nanoparticle concentration on the shaping characteristics is concerned, we have found that above the critical irradiation fluence, the deformation effect becomes very sensitive to the initial concentration of the nanoparticles.