Photocatalytic activity of P-doped TiO2 photocatalyst.

In this study, P-doped TiO2 photocatalysts with different molar percentages (in the range 0.071-1.25 mol %) of the non-metallic element were prepared and their photocatalytic activity under visible light irradiation was tested. All achieved samples were characterized by XRD, Raman, UV-Vis DRS and SEM-EDX techniques. XRD and Raman analysis showed that all doped photocatalysts were in anatase phase and evidenced that P ions were successfully incorporated into the TiO2 crystal lattice, affecting also the crystallinity degree of the P-doped TiO2 photocatalysts. Noticeably, the UV-Vis DRS spectra evidenced that the highest redshift in absorption edge was observed for the photocatalyst with the lowest P content (0.071PT), which showed also the lowest bandgap (2.9 eV). The photocatalytic performances of all P-doped TiO2 samples were compared with that of commercial TiO2 by evaluating the decolorization of methylene blue (MB) dye under visible light irradiation. Results showed that phosphorus doping strongly promoted photocatalytic activity in the presence of visible light. Furthermore, the most active photocatalyst in visible light tests (0.071PT) also showed better photocatalytic activity than commercial TiO2 in the decolorization of MB under simulated sunlight irradiation. Finally, 0.071PT photocatalyst was preliminarily tested against Escherichia coli (E. coli) under simulated solar light, showing an inactivation efficiency of 90% after 2 h of treatment time.

Copolymerization of L-Lactide and ε-Caprolactone promoted by zinc complexes with phosphorus based ligands.

The zinc complexes 1 and 2 bearing chelating phosphorous based pincer ligands were found to catalyze the ring-opening copolymerization of L-lactide and ε-caprolactone in the melt at 110 °C to obtain a series of random copolymers in which the monomer distributions were coherent with the monomer ratio in the feed. All the obtained copolymers showed high molecular masses with monomodal and moderately narrow distributions. The thermal properties of the achieved copolymers (Tg, glass transition temperature, and Tm, melting temperature) were strongly dependent on their composition. A linear dependence of Tg with molar percentage of lactide in the copolymers was observed over a temperature range from -59 °C (pure polycaprolactone) to 55 °C (pure polylactide).

Aluminium complexes of salanol ligands: coordination chemistry and stereoselective lactide polymerization.

The tetradentate dianionic {ONNO}-type salanol ligands featuring phenolate and alcoholate arms and a chiral-bipyrrolidine core are introduced. The diastereoselectively-formed {ONNO}-Al-OBn complexes catalyze the ring-opening polymerization of rac-lactide and meso-lactide by either the dual stereocontrol or the chain-end stereocontrol mechanisms to give PLAs of all possible tacticities.