Facile, rapid and efficient doping of amorphous TiO 2 by pre-synthesized colloidal CdS quantum dots

New insight into the selective photocatalytic oxidation of RhB through a strategy of modulating radical generation

“…The photogenerated e À on the surface of CdS QDs can be scavenged by surface-adsorbed oxygen (eqn (2)), and h + can be le in the CdS QDs. 62 When the h + is scavenged, the amount of $O 2 À and $OH also simultaneous decrease, so that the curves of $O 2 À and h + are accidentally overlapped.…”

Visible light photoluminescence in TiO2/CdS nanopowders synthesized by sol-gel route: effect of gel aging time

“…TiO 2 /CdS composites were prepared by direct hydrolysis technique using pre-synthesized aqueous colloidal solution of CdS nanoparticles. The details of TiO 2 /CdS preparation can be found in [24]. In brief, a certain amount of titanium (IV) n-butoxide was dissolved in the aqueous colloidal CdS solution.…”

“…Currently, several synthesis strategies are being actively developed to obtain visible photoactive TiO 2 /CdS nanocomposites, and by varying the synthesis conditions it is possible to change their structural properties, defect states and electron structure for tuning PL emission. In one of them, pre-synthesized CdS nanoparticles are directly incorporated into TiO 2 matrix during titania formation process via sol-gel route [21][22][23][24]. As a rule, the influence of the initial concentrations of the sensitizing additive on the emission and photocatalytic properties of sol-gel TiO 2 /CdS composites is studied [21].…”

“…As a rule, the influence of the initial concentrations of the sensitizing additive on the emission and photocatalytic properties of sol-gel TiO 2 /CdS composites is studied [21]. At the same time, when preparing TiO 2 /CdS composites, the sol-gel route is sometimes used with low-temperature heating of the sol-gel [23,24], the effect of which on PL emission was not monitored. Recently, a new technique for producing photoactive composites TiO 2 /CdS was proposed, based on a modified sol-gel method using pre-synthesized CdS colloidal nanoparticles and low-temperature gel aging stage at boiling point [24].…”

“…At the same time, when preparing TiO 2 /CdS composites, the sol-gel route is sometimes used with low-temperature heating of the sol-gel [23,24], the effect of which on PL emission was not monitored. Recently, a new technique for producing photoactive composites TiO 2 /CdS was proposed, based on a modified sol-gel method using pre-synthesized CdS colloidal nanoparticles and low-temperature gel aging stage at boiling point [24]. Gel aging time, as has been shown, can affect the crystallinity degree of titania (amorphous/nanocrystalline ratio), and content of the incorporated CdS nanoparticles [25].…”