Arrays of needle-like TiO2/CdS nanorod heterostructure photoelectrodes with enhanced photoelectrochemical properties fabricate by pulsed laser deposition

To improve the photoelectrochemical properties of TiO2/CdS composite nanorod electrodes, we developed a one-step quantum dot (QD) synthesis and assembly process based on pulsed laser deposition (PLD). An advantage of this method is that it does not involve ligand-exchange processing or wet chemical methods that might destabilize the QD attachment. By using PLD, CdS QDs were successfully grown on a dense array of TiO2 nanorods, forming needle-like heterostructures whose photophysics depends on the laser pulse energy. The XRD results indicated that the products were composed of the tetragonal rutile, TiO2 and hexagonal CdS. The TiO2/CdS heterostructures fabricated with this method are very stable and exhibit promising photoelectrochemical characteristics for photovoltaic applications. The best results are obtained for a PLD laser pulse energy of 300 mJ, which produces TiO2/CdS heterostructure nanorod electrodes that, when illuminated at AM 1.5 G, have a photocurrent density exceeding 4.7 mA cm(-2) at 0 V versus a saturated calomel electrode.

Automated summary

Researchers improved the photoelectrochemical properties of TiO2/CdS composite nanorod electrodes through a one-step quantum dot synthesis and assembly process. Using pulsed laser deposition, CdS quantum dots were successfully grown on TiO2 nanorods, forming stable TiO2/CdS heterostructures.