Polymer brushes assisted loading of high density CdS/CdSe quantum dots onto TiO ₂ nanotubes and the resulting photoelectric performance

Cadmium sulfide (CdS) and cadmium selenide (CdSe) quantum dots (QDs) are sequentially loaded onto anodized TiO ₂ nanotubes to fabricate a CdS/CdSe co-sensitized photoelectrode for visible light response. These QDs are loaded on TiO ₂ nanotubes by polymer brushes assisted in situ formation, and they are distributed uniformly around both inner and outer walls of TiO ₂ nanotubes. The interpenetrating polymer can provide a superior nano-confined environment and will prevent the nanoparticles from growing further during nucleation. More importantly, the potential advantage of using polymer brushes is the capability of tuning the loading amount of QDs via multiple cation exchange. The photoresponse of CdS/CdSe-TiO ₂ nanotubes has been efficiently extended into the visible-light region, indicating potential applications in solar cell devices.