This study reports an investigation on the synergistic effect of sensitization by CdSe and exposure of TiO2′s (0 0 1) facet towards the photoactivity of CdSe-TiO2 nanostructures for photoreduction of bicarbonate. Here, TiO2 nanoparticles with spindle-like morphology with high exposure of (0 0 1) facet were successfully synthesized. Whereas, different sizes of CdSe particles were prepared and integrated to TiO2 using 3-mercopatopropionic acid (MPA) as the linker. Based on the spectroscopic analyses, it was found that the as-prepared CdSe-TiO2 were able to absorb a broad spectrum of light energy from UV to visible as the result of band overlap between CdSe and TiO2. Besides, results demonstrated that this band overlap also caused the blueshift in the TiO2 bandgap, where the magnitude of the shift was found to be proportional to CdSe size. Furthermore, it is revealed that the as-prepared CdSe-TiO2 was able to facilitate the photoreduction of bicarbonate efficiently. Interestingly, the photoactivity of the nanocatalysts was also found to be proportional to the size of CdSe. This excellent photoactivity was believed due to the presence of type II band alignment as the result of the conduction band overlap between TiO2 and CdSe. Additionally, such activity could also be attributed to the formation of surface heterojunction of TiO2′s (1 0 1) and (0 0 1) facets, which facilitates the efficient charge separation.
- Crystal facet
- Quantum dots