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Nanoparticles of zinc oxide (ZnO) combined with a Jania rubens (JR) biosorbent have been embedded in a sodium alginate (SA)–polyvinyl alcohol (PVA) matrix. This hybrid biosorbent was characterized by FTIR, and the presence of functional groups involved in the adsorption of Pb2+ was revealed. SEM/EDX analyses have shown that the hybrid biosorbent exhibited porous microstructures which are decorated with ZnO nanoparticles (hydrodynamic size of 68 ± 2 nm). The removal of Pb2+ from aqueous medium was thoroughly investigated. The adsorption capacity has been measured at qe = 39.1 mg g−1 at pH = 5 and T = 303 K with the concentration of biosorbent and Pb2+ at 2.0 g L−1 and 100 mg L−1, respectively. The Freundlich and Langmuir isotherms have been used to model the adsorption process, from which the maximum adsorption capacity (qm) of the hybrid biosorbent was calculated to be 111 mg g−1. The adsorption kinetics are represented by a pseudo-second order model. In addition, the hybrid biosordent was regenerated and reused for four cycles for the removal of Pb2+. [ABSTRACT FROM AUTHOR]

Titanium dioxide aerogel (TiAP) powders were prepared by lyophilization of peroxo-polytitanic gels followed by annealing at 800 °C to obtain an anatase structure. The surface modification of TiAP was performed for the first time by low amounts of Ce ions (in the range of 0.0025 to 0.025 wt%) using a wet impregnation method. The photocatalytic activity of the aerogel samples was investigated for the removal of different organic pollutants (i.e., Rhodamine B, phenol and caffeine) and the results were compared with the reference P25. Both TiAP and Ce ion surface-modified TiAP (Ce/TiAP) have exhibited better degradation efficiencies for the removal of pollutants than P25, especially for Ce/TiAP with an enhancement in the degradation efficiencies of +18% and +37% for the removal of caffeine and Rhodamine B, respectively. These results have been partly explained by the high active surface area of Ce/TiAP compared to TiAP as well as its better photoelectrochemical properties which have shown, for instance, ∼10% increased incident photon-to-electron conversion efficiency at 360 nm. Interestingly, the energetic position of the valence band maximum of Ce/TiAP is shifted from 3.2 eV to 2.8 eV (compared to TiAP), thus improving the generation of reactive oxygen species (ROS), especially hydroxyl radicals. Indeed, the presence of HO˙ is confirmed by electron paramagnetic resonance, and fluorescence spectroscopy and their photoinduced generation are enhanced in the case of Ce/TiAP. Finally, the surface modification of TiAP by cerium ions led not only to better photoinduced properties, thus limiting the electron–hole pair recombination, but also to the improvement of ROS generation via different plausible mechanisms. [ABSTRACT FROM AUTHOR]

Using a Nb-modified BiVO4 film, the photo-induced properties in Methicillin-resistant Staphylococcus aureus (MRSA) inactivation under simulated solar light reached 43% after 1 hour of irradiation, while 72% of Rhodamine B was degraded after 3 hours. To evaluate the efficiency of Nb–BiVO4, its photo-performance was compared with that of BiVO4/TiO2 composites and pure BiVO4. [ABSTRACT FROM AUTHOR]