Sonication-Assisted Synthesis of CdS Quantum-Dot-Sensitized TiO₂ Nanotube Arrays with Enhanced Photoelectrochemical and Photocatalytic Activity

Abstract

A sonication-assisted sequential chemical bath deposition (S-CBD) approach is presented to uniformly decorate CdS quantum dots (QDs) on self-organized TiO2 nanotube arrays (TNTAs). This approach avoids the clogging of CdS QDs at the TiO2 nanotube mouth and promotes the deposition of CdS QDs into the nanotubes as well as on the tube walls. The photoelectrochemical and photocatalytic properties of the resulting CdS-decorated TNTAs were explored in detail. In comparison with a classical S-CBD approach, the sonication-assisted technique showed much enhancement in the photoelectrochemical and photocatalytic activities of the CdS QDs-sensitized TNTAs.

Ultrathin nanoflakes constructed erythrocyte-like Bi2WO6 hierarchical architecture via anionic self-regulation strategy for improving photocatalytic activity and gas-sensing property

“…In addition, most of electrons react with H 2 O 2 molecules in the water to yield abundant hydroxyl radicals • OH to remove RhB molecules. Meanwhile, the holes can also directly degrade RhB molecules [51,52]. It should be pointed out that H 2 O 2 serves as an efficient electron scavenger, which can also facilitate separation and transfer of charge carriers to improve the photocatalytic activity.…”

ZnO quantum dots decorated 3DOM TiO2 nanocomposites: Symbiose of quantum size effects and photonic structure for highly enhanced photocatalytic degradation of organic pollutants

“…The quantum size effect (QSE) alters the energy levels of the conduction and the valence band edges in the coupled semiconductor systems, which favors the interparticle electron transfer resulting in low carrier recombination rate. Xie et al [49] showed that CdS QDs sensitized TiO 2 nanotubes exhibited high photocatalytic activity towards methyl orange (MO) dye due to the quick charge transfer from CdS to TiO 2 conduction band. Another important work carried out by Wang et al [50] showed clearly the QSE in photocatalysis.…”

Fabrication of inverse opal TiO2-supported Au@CdS core–shell nanoparticles for efficient photocatalytic CO2 conversion

“…[21][22][23][24][25] Among these tactics, constructing TiO 2 -based heterostructure has been demonstrated effective for improving photocatalytic efficiency through promoting the photogenerated charge separation, harvesting visible light and facilitating CO 2 activation. [26,27] Various types of second-component semiconductor of TiO 2 -based heterostructure have been reported, such as CdS, [28] CeO 2 [29] and ZrO 2 [30] and so on. On this basis, an electron transfer mediator (Pt, [31] Au, [32] and graphene oxide [33][34][35] ) embed in the heterostructure interface can strengthen the interface charge transfer and result in a vectorial electron transfer via a Z-scheme system, [36] which can efficiently improve photogenerated separation and photocatalytic activity.…”