Impact of the Precursor on the Physicochemical Properties and Photoactivity of TiO Nanoparticles Produced in Supercritical CO.

The synthesis of TiO nanoparticles (NPs) in supercritical media has been reported over the last two decades. However, very few studies have compared the physicochemical characteristics and photoactivity of the TiO powders produced from different precursors, and even fewer have investigated the effect of using different ratios of hydrolytic agent/precursor (HA/P) on the properties of the semiconductor. To bridge this knowledge gap, this research focuses on the synthesis and characterization of TiO NPs obtained in a supercritical CO medium from four different TiO precursors, namely diisopropoxytitanium bis (acetylacetonate) (TDB), titanium (IV) isopropoxide (TIP), titanium (IV) butoxide (TBO), and titanium (IV) 2-ethylhexyloxide (TEO).

Photocatalytic Reduction of CO with N-Doped TiO-Based Photocatalysts Obtained in One-Pot Supercritical Synthesis.

The objective of this work was to analyze the effect of carbon support on the activity and selectivity of N-doped TiO nanoparticles. Thus, N-doped TiO and two types of composites, N-doped TiO/CNT and N-doped TiO/rGO, were prepared by a new environmentally friendly one-pot method. CNT and rGO were used as supports, triethylamine and urea as N doping agents, and titanium (IV) tetraisopropoxide and ethanol as Ti precursor and hydrolysis agent, respectively.