It has previously been reported that epitaxial growth of ZnO can be obtained at low temperatures by atomic layer deposition (ALD) onto a GaN (0001-Ga) surface, corresponding to a ~2.3% compressive lattice mismatch of the deposited ZnO. The question addressed here is the atomic ordering of deposited ZnO as a function of the lattice mismatch between ZnO and several single-crystal seeding surfaces. We have deposited ZnO using ALD onto either the (111) cubic or (0001) hexagonal surfaces of a set of available single-crystal substrates (GaAs, InP, GaN, SiC), for which the lattice mismatch varies over a wide range of values, positive and negative. It is found that deposition onto surfaces with very high extensive lattice mismatch (GaAs, InP) leads to polycrystalline ZnO, similar to the configuration obtained on an amorphous SiO₂ surface. In contrast, ZnO ALD deposition onto both 2H-GaN (0001-Ga) and 4H-SiC (0001-Si) surfaces with lower and compressive mismatch leads to epitaxial ordering over the whole substrate temperature range of 180–250 °C.

We used a sol–gel spin coating technique to synthesize nanocomposite thin films based on zinc oxide (ZnO) loaded with silver nanoparticles (NPs). We tested these ZnO/Ag NPs photocatalysts, with a thickness of about 100 nm, for the photodegradation of the indigo carmine dye solution. The study focused on the effects of Ag NPs on the ZnO matrix as well as the impact of their concentration on the photocatalytic performance of the nanocomposite. The study also highlighted the high stability of the photocatalytic performance of these nanocomposites. This work is a contribution in the search for non-toxic thin film photocatalysts that is usable under solar radiation for the treatment of contaminated wastewater. Innovation in the field of heterogeneous photocatalysis requires the use of solar resource with efficient results in terms of photocatalytic performance.

We used sol-gel and spin-coating in the original configuration of a liquid deposition process to synthesize particularly thin ZnO films (<100 nm) with nano-granular morphology, high grain orientation and variable optical properties. The concentration of the zinc salt, the concentration of the chelating agent, the nature of the solvent and the substrate material have been identified as key parameters that determine the microstructure of the deposited layer and thus its final properties. The thorough and practical examination of the effects of the synthesis parameters evidenced a three-step growth mechanism for these ZnO thin films: (i) a reaction of precursors, (ii) a formation of nuclei, and (iii) a coalescence of nanoparticles under thermal annealing. The growth of these very thin films is thus conditioned by the interaction between the liquid phase and the substrate especially during the initial steps of the spin coating process. Such thin ZnO films with such nano-granular morphology may be of great interest in various applications, especially those requiring a large active surface area.

The protection of 316L stainless steel in 3% NaCl by the essential oil of Thymus satureoides has been studied by many techniques such as potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy analysis (EDXS). The results show that the corrosion rate of 316L stainless steel decreases with the increase in the concentration of the inhibitor up to an efficiency of 82% for a concentration of 1600 ppm. The Thymus satureoides oil acts as an anode inhibitor. The values of the inhibition effectiveness obtained from the polarization curves and electrochemical impedance spectroscopy (EIS) are in good agreement. Geometry optimization and calculation of the structural and electronic properties of the inhibitor molecular system have been carried out using density functional theory DFT (B3LYP, BMK and M062X) level with a 6-311++G** basis set.

This article concerns the elaboration and the characterization of a novel biobased potato starch-beet pulp composite for packaging applications as cushion foams. A twin-screw extruder was used to elaborate composite foams. SEM observations of these materials were conducted, and thermomechanical properties were studied in terms of thermal transitions (TGA, DSC) and viscoelastic properties (DMA). The effect of relative humidity content on viscoelastic properties was analyzed as a function of frequency. The different test results show that the composite structures are homogeneously mixed. The sponge-like structure of the beet-pulp disappears indicating a good compatibility between the two mixed constituents. The DSC curve of starch-beet pulp foam shows a single thermal transition at 153.6 °C, indicating the thermal homogeneity of the obtained composite material. The density value of starch-beet pulp foam is higher than conventional foams, but this can be optimized by adjusting the technological parameters of the extruder. The viscoelastic properties of the developed materials depend on the relative humidity.

Developing new stirred gas–liquid–solid reactors with high mass transfer capabilities is still a challenge. In this publication, we present a new concept of multiphase reactor using a stationary catalytic foam and a gas-inducing impeller. The gas–liquid (GL) and liquid–solid (LS) mass transfer rates in this reactor were compared to a stirred reactor with basket filled with beads. Batch absorption of hydrogen and measurement of $\alpha$-methylstyrene hydrogenation rate on $Pd/A{l}_2{O}_3$ catalyst were used to evaluate $k_{GL}{a}_{GL}$ coefficients and $k_{LS}$ coefficients, respectively. With similar LS transfer rates to the basket-reactor and much higher GL transfer rates, the new reactor reveals a very promising tool for intrinsic kinetics investigations.