Quantum Materials Corp. (fka QTMM)

[dockzef]

Synergistic Effect of CdSe Quantum Dot
Sensitization and Nitrogen Doping of TiO2
Nanostructures for Photoelectrochemical
Solar Hydrogen Generation

Jennifer Hensel,† Gongming Wang,† Yat Li,* and Jin Z. Zhang*
Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064

ABSTRACT We report the synthesis and photoelectrochemical (PEC) studies of TiO2 nanoparticles and nanowires simultaneously
doped with nitrogen and sensitized with CdSe quantum dots (QDs). These novel nanocomposite structures have been applied
successfully as photoanodes for PEC hydrogen generation using Na2S and Na2SO3 as sacrificial reagents. We observe significant
enhanced photoresponse in these nanocomposites compared to N-doped TiO2 or CdSe QD sensitized TiO2. The enhancement is
attributed to the synergistic effect of CdSe sensitization and N-doping that facilitate hole transfer/transport from CdSe to TiO2 through
oxygen vacancy states (Vo) mediated by N-doping. The results demonstrate the importance of designing and manipulating the energy
band alignment in composite nanomaterials for fundamentally improving charge separation and transport and thereby PEC properties.