The first ever synthesis of submicron-sized rare earth hexaborides (RB 6 ; R ) La, Ce, Nd, Sm, Eu, and Gd) with a cubic morphology has been obtained by the single-step synthesis of the RAPET (reaction under autogenic pressure at elevated temperature) technique at a relatively low temperature of 900°C using metal acetate precursors. The synthesized materials have been characterized for their structural (XRD, XPS, and Raman) and morphological (TEM, HRTEM, and FESEM) properties. The XRD pattern confirms the phase purity and the formation of a single phase compound of rare earth hexaborides. Raman spectra elucidate the active vibrational modes of the hexaborides. The TEM and FESEM images clearly show that the hexaborides are submicron in size with a cubic morphology. The SAED patterns reveal the single crystalline nature of the products.

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A novel one-step soft solution-processing route called the solvothermal-copolymerization technique was successfully developed for in situ fabrication of polystyrene (PS)/CdS nanocomposites embedded with CdS nanowires in ethylenediamine media at lower temperatures (80−140 °C). In this route, the polymerization of the monomers and the formation of the CdS nanocrystallites occur simultaneously in a certain temperature range. The results of X-ray powder diffraction, transmission electron microscopy, and high-resolution transmission electron microscopy confirmed that the embedded CdS nanowires, with diameters of 4−15 nm and lengths up to several micrometers, have [001] preferential orientation. Both temperature and solvent were found to play a key role in the synthesis of the nanocomposites. The produced novel hybrid nanocomposites display obvious quantum size effects and interesting fluorescence features. The spectroscopic properties of the PS/CdS nanowire nanocomposites were found to be sensitive to synthetic conditions, including the concentrations of Cd2+ or the monomer, temperature, and reaction time.

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A series of SnO2–ZnO composite nanostructured (thin) films with different amounts of SnO2 (from 0 to 50 wt %) was prepared and deposited on a miniaturized porous alumina transducer using the sol–gel and dip coating method. The transducer, developed by our research group, contains Au interdigital electrodes on one side and a Pt heater on the other side. The sensing films were characterized using SEM and AFM techniques. Highly toxic and flammable gases (CO, CO2, CH4, and C3H8) were tested under lab conditions (carrier gas was dry air) using a special gas sensing cell developed by our research group. The gas concentrations varied between 5 and 2000 ppm and the optimum working temperatures were in the range of 210–300 °C. It was found that the sensing performance was influenced by the amount of oxide components present in the composite material. Improved sensing performance was achieved for the ZnO (98 wt %)–SnO2 (2 wt %) composite as compared to the sensors containing only the pristine oxides. The sensor response, cross-response and recovery characteristics of the analyzed materials are reported. The high sensitivity (R S = 1.21) to low amounts of CO (5 ppm) was reported for the sensor containing a composite sensitive film with ZnO (98 wt %)–SnO2 (2 wt %). This sensor response to CO was five times higher as compared to its response to CO2, CH4, and C3H8, thus the sensor is considered to be selective for CO under these test conditions.