A convolutive profile-fitting procedure is described for analysing X-ray diffraction peak profiles broadened by microstructural factors (crystallite size and lattice disorder). The method requires, in a first stage, an accurate determination of the instrumental function, which is subsequently convoluted with a parametric function adjusted to fit the diffraction profile intensities of the specimen investigated. In the calibration of the instrument function throughout the angular range 20-145 ° in 20, 58 peaks of a well crystallized a-quartz specimen are examined. Provision is made to include in the instrument function an exponential function containing an angle-dependent asymmetry parameter. In the present methodology, a pseudo-Voigt function is suggested to obtain the shape factors (integral breadth, peak width at half maximum, Gaussian content) that contain useful information related to the microstructural properties in the frame of the so-called

A synthesis of variably functionalized thiol-protected palladium nanoparticles (Pd-NPs) is presented. The nanoparticle syntheses are performed in acetoneÀwater or tetrahydrofuranÀwater solutions, without making use of either phase-transfer agents or complex purification procedures of the as-synthesized nanoparticles. Small and mostly monodisperse thiol-protected Pd nanoparticles (Pd-NPs ∼ 2 nm) have been prepared with 11-mercaptoundecanoic acid (MUA), 9-mercapto-1-nonanol (MN), 1-dodecanethiol (DT), or mixtures thereof, and a simple scale-up synthesis is also proposed. The role of Pd II -thiolate species as metal precursors in the stage of nanoparticle synthesis and the influence of the reaction parameters on the final Pd-NPs size and size distribution are discussed. The formation of mixed-monolayer protected nanoparticles is achieved, with the final monolayer composition dictated by the thiols, initial molar ratio. Overall, the procedure presented here allows the preparation of functionalized nanoparticles with a high density of functional groups at the edge of the monolayer, with no need of place-exchange reactions. Specific postfunctionalization procedures conducted at the acid groups of the MUA-Pd monolayer are reported so as to widen the potential applicability of these amphiphilic nanoparticle precursors with respect to different applications in the field of material science. Finally, the successful use and the easy recycling/reuse of the Pd-NPs in a model Suzuki cross-coupling reaction are presented.

We give two general integral expressions for the first and second derivatives of the so-called stick probability functions which are commonly used in analyzing x-ray-scattering results. Then it is shown that by letting the length of the stick go to zero, the limit of the second derivative can be expressed in terms of an integral over the singularity lines of the surfaces which separate the different phases of the sample. In this way one has achieved the generalization of the well-known result that the limit of the second derivative is always zero when phase boundaries are smooth.

There is the need for reproducible, simple, high-yielding synthetic protocols aimed at obtaining carbon dots (CDs) with controlled fluorescence, photothermal and photochemical behavior, surface properties, biocompatibility, tumor targeting ability, drug absorption biodistribution, and tumor uptake. This Letter describes a systematic study on the effect of glucose, fructose, and ascorbic acid as starting materials for the preparation of highly luminescent CDs, characterized by a blue emission. Their composition and morphology are investigated by titration of OH surface groups, spectroscopic techniques, and high-resolution transmission electron microscopy (HR-TEM), and their toxicity was tested toward HeLa cells. CDs made using fructose were toxic, while those made from glucose and ascorbic acid showed good biocompatibility. The reproducible and simple synthetic procedure yields luminescent biomass-derived CDs for combined cancer therapy and diagnostics. Their doxorubicin (DOX) drug uptake was measured by spectrofluorimetry, indicating a crucial role of the morphologies of the CDs in controlling DOX loading. The glucose derived CDs showed up to 28% w/w of DOX loading.

Several antimony and platinum doped tin dioxide electrodes supported on titanium have been characterized by X-ray diffraction (XRD) and X-ray absorption spectroscopy (EXAFS) techniques. Ti/SnO2−Sb electrodes show a rutile-type nanostructure with a distorted unit-cell because of the substitution of the Sn(IV) ion by Sb(V). The presence of platinum on the electrode coating modifies the lattice parameters of the SnO2 cell due to an amorphization of tin oxide layers. The structural modifications on the different electrode after anodic polarization−deactivation have been analyzed

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An electrochemical and X-ray diffraction study has been conducted on the formation of lead dioxide deposits on platinum, from nitric acid solutions, as a function of potential and temperature. It has been shown that these parameters strongly influence the morphology and electrocatalytic activity of the PbO 2 films. The electrodeposition process is satisfactorily described by an electrochemical, chemical, electrochemical mechanism: ͑i͒the second electron transfer stage and Pb 2ϩ diffusion control the dioxide formation in the lower and higher overpotential range, respectively. Temperature and potential ͑or current͒ are important parameters in the electrodeposition process. Depending on the potential region, the process can be kinetically or diffusion controlled. In an acid electrolyte, where mainly the ␤-PbO 2 modification is electrodeposited, the amount of ␣-phase impurity increases with increasing potential in the kinetically controlled region and decreases in the diffusion controlled domain. In addition, relatively low electrodeposition potentials and high temperatures favor an increase of the crystallite size with preferred crystallographic orientation for both ␣and ␤-PbO 2 modifications. The temperature of the growth solution affects the crystallinity of the resulting oxide deposits and has a marked effect on their performance as anodes in processes at high positive potentials such as ozone generation.

Nanophasic CeO 2 -based thin films were grown at low temperatures on SiO 2 and Si(100) by plasma-enhanced (PE) CVD from a Ce IV b-diketonate first generation precursor. Film depositions were carried out in low-pressure Ar±O 2 plasmas at temperatures between 150 C and 300 C. The film microstructure was investigated by glancing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM), while the surface and in-depth chemical composition was studied by X-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS), respectively. Optical properties were analyzed by UV-vis optical absorption. Nanostructured CeO 2 -based films, with crystal size less than 6 nm and a controllable Ce IV /Ce III ratio, were obtained at temperatures even lower than that required for precursor vaporization (170 C). In particular, TEM analyses showed an island growth mode and different microstructural features as a function of the substrate used.