Quenching effect of cerium oxide nanoparticles on singlet oxygen: validation of the potential for reaction with multiple reactive oxygen species.

Here we studied cerium oxide nanoparticles (nanoceria) as an agent for the future treatment of oxidative damage by validating and evaluating its scavenging activity towards reactive oxygen species (ROS) . Nanoceria has been shown to mimic the activities of superoxide dismutase and catalase, degrading superoxide (O) and hydrogen peroxide (HO). We examined the antioxidative activity of nanoceria, focusing on its ability to quench singlet oxygen (O) in an aqueous solution.

Characterization of oxides obtained by heating a mixture of peroxoniobic acid and peroxotitanic acid.

Nb-doped TiO(2) particles were prepared by heating a mixture of peroxotitanic acid and peroxoniobic acid in air. When the heating temperature was more than 1173 K, the dominant phase obtained was rutile TiO(2), along with a small amount of TiNb(2)O(7). The relationship between the lattice parameters of the obtained rutile TiO(2) depended on the molar fraction of Nb/(Ti + Nb).

Comparative examination of titania nanocrystals synthesized by peroxo titanic acid approach from different precursors.

Titanium dioxide nanocrystalline particles were synthesized by peroxo titanium acid (PTA) approach from titanium alkoxide and inorganic salt precursors, and their structural and surface properties, porosities, and photocatalytic activities were comparatively examined by XRD, TG/DTA, DRIFT, UV-vis, low temperature N(2) adsorption, and methyl orange (MO) degradation. It was found that nanoparticles with single anatase phase can be obtained from alkoxide precursor even near room temperature if synthesis conditions are appropriately controlled. PTA-derived anatase nanoparticles from titanium alkoxide precursor have smaller crystalline sizes and better porosities, and contain less amount of peroxo group and no organic impurities as compared to those from TiCl(4) precursor.

Low temperature synthesis and characterization of porous anatase TiO2 nanoparticles.

An ethanol solution of Ti-peroxy compounds was prepared from the ethanol solution of titanium isopropoxide (Ti(O-iPr)4) and H2O2. Heating of the ethanol solution of the Ti-peroxy compounds at 348 K formed a Ti-peroxy gel, and heat treatment of the gel at 348 K for more than 6 h formed gels that consisted of anatase nanoparticles. The diameter of the anatase nanoparticles increased from 9 to 15 nm as the heating time increased from 6 to 48 h.

Low-temperature synthesis of niobium oxide nanoparticles from peroxo niobic acid sol.

A peroxo niobic acid sol was prepared by peptization of the niobic acid precipitate (Nb2O5.nH2O) with a H2O2 aqueous solution. Crystallized Nb2O5 nanoparticles and niobic acid nanoparticles were obtained by heating the peroxo niobic acid sol.