Gwenaël Corbel

Lead-free zero-dimensional (0D) hybrid halide perovskites A ₂ SnX ₆ are promising candidates for stable deep-UV optoelectronics, however, the chloride end-members of the series remain underexplored.

Toxic hydroxyl radicals produced by Cu(OH)F particles completely disinfect water contaminated with E. coli after only 3 hours.

A new lead-free organic–inorganic hybrid compound based on Bi( iii ), namely tris(tetraethylammonium) nona-idodibismuthate( iii ), [(C ₂ H ₅ ) ₄ N] ₃ Bi ₂ I ₉ , has been successfully synthesized using a slow evaporation technique.

Alkylammonium halogenoferrates have attracted considerable attention due to their structural versatility and functional potential.

A model bacterial membrane is degraded by exposure to Cu(OH) ₂ nanorods in oxidative medium. Neutron reflectometry revealed the exact mass distribution, and provided an accurate methodology to study the effect of metal nanoparticles on biomembranes.

Both nanometer-sized CuO and MgO particles exhibit bactericidal activities against Staphylococcus aureus and Escherichia coli, two bacteria causing healthcare-associated infections. The solid solution Cu_1−xMg_xO is potentially interesting for biomedical applications as one of the compositions could have a much higher bactericidal activity than the parent CuO and MgO oxides considered separately. But, to date, no Vegard's law proves the real existence of such a solid solution. This study was aimed at shedding light on the solubility of Mg²⁺ ions in CuO nanoparticles and its impact on the free oxygen radicals they produce, the quantity of which determines their bactericidal performance. The solid solution Cu_1−xMg_xO does exist and particles were synthesized as nanorods of 50–60 nm length by thermally decomposing at 400 °C the single source precursors Cu_1−xMg_x(OH)₂. Vegard's laws exist only in the compositional range 0 ≤ x ≤ 0.1, due to the low capacity of the distorted NaCl-type structure to accommodate regular coordination [MgO₆] octahedra. Only neutron diffraction allowed the detection of the small amount of MgO nanoparticles present as impurity in a 10 g sample beyond the solubility limit of x = 0.1. In this series, CuO nanorods remain the most active against E. coli and S. aureus with reduction in viability of 99.998% and 98.7% after 180 min in water, respectively. Our synthesis route has significantly increased the activity of pure CuO nanoparticles beyond the values reported so far, especially against E. coli. The bactericidal performances of CuO and the magnesium-substituted counterparts (i.e. Cu_1−xMg_xO) are not linked to cupric ions they release in water since their mass concentrations after 180 min are much lower than minimal concentrations inhibiting the growth of E. coli and S. aureus. These CuO nanorods kill bacteria in water because they produce a large quantity of free oxygen radicals in the presence of H₂O₂ only, the majority of which are highly toxic HO˙ radicals. Mg²⁺ ions have a detrimental effect on this production, thus explaining the lowest bactericidal performance of Cu_1−xMg_xO nanorods. Definitive knowledge of the toxicity of Cu_1−xMg_xO nanoparticles towards bacteria in water is now available.

A new organic inorganic hybrid [TPA]₂CoBr₄, where TPA = [(C₃H₇)₄N]⁺ (i.e., tetra-propyl-ammonium) compound has been synthesized by slow evaporation method at room temperature.

Toxic hydroxyl radicals produced by Cu(OH)₂ nanorods completely disinfect water contaminated with S. aureus and E. coli after only 180 min.

The alkylammonium halogenoferrate families are subjected to diverse studies according to their wide field application. However, these compounds show various transitions depending on the preparation process. In this paper, the [(C₂H₅)₄N]FeCl₄ compound was successfully synthesized using a slow evaporation solution growth method at room temperature. An optical absorption measurement confirms the semiconductor nature with a band gap around 2.95 eV. The X-ray powder diffraction (XRPD) data confirmed the formation of a single-phase with hexagonal-type structure. The differential scanning calorimetry (DSC) indicated that the [(C₂H₅)₄N]FeCl₄ compound undergoes eight reversible phase transitions between 193 and 443 K. At high temperature (T > 423 K) the plastic nature of the crystals was confirmed. Temperature-controlled X-ray diffraction reveals that the thermal expansion of the crystal structure is non homothetic in the (a,b) plane and along the c axis. The temperature dependence of the Raman spectra up to 443 K revealed specific reorientations and molecular displacements of the organic and inorganic components associated with the phase transitions. We aim to thermally stabilize the [(C₂H₅)₄N]FeCl₄ compound which has a band gap suitable for photocatalytic processes.