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Graphical abstract Highlights • A nanocomposite nanostructured Ag 2 S sensitized ZnO NRAs synthesised via hydrothermal method. • Photoelectrochemical analysis verified that the Ag 2 S/ZnO NRAs under heat treatment gave better photocurrent response. • Nanocomposite structure shows substantial improvement in charge collection efficiency. Abstract Low temperature hydrothermal method was used to produce a large surface area ZnO NRs on conductive glass. The same method was used to fabricate a photoelectrode of Ag 2 S quantum dots onto the nanorod arrays. Ag 2 S QDs/ZnO NRAs heterostructure was employed as photoanode in a standard 3-electrodes photoelectrochemical cell. A significant enhancement in the photoelectrochemical performance was observed for the Ag 2 S QDs/ZnO upon heat treatment 400 °C which displayed an impressive photoconversion efficiency of 4.08% by achieving ∼10-times higher compared to bare ZnO NRAs. This enhancement was attributed to the improved morphological structure, crystallinity and optical properties of the synthesised heterostructures. [ABSTRACT FROM AUTHOR]

Solar energy is an alternative sustainable energy resource that can be harvested using photoelectrochemical cell comprised of inorganic sensitized nanostructured oxide semiconductor electrode. In this work, pulse electrodeposition was used to deposit CdSe onto titanium dioxide nanotube arrays (TiO 2 NTAs). TiO 2 NTAs are commonly used in the nanostructured photoelectrochemical cells due to their high surface area, fewer interfacial grain boundaries and excellent charge transfer between interfaces. Duty cycle of pulse electrodeposition played an important role in the formation of CdSe nanoparticles. A significant enhancement in the photoelectrochemical performance was observed for the heterostructure of CdSe/TiO 2 NTAs. CdSe/TiO 2 NTAs prepared at 50% duty cycle exhibited maximum photocurrent of 1.94 mA cm −2 and photoconversion efficiency of 1.18% which was 59 times higher than bare TiO 2 NTAs. These results demonstrated that significant enhancement in the photoconversion efficiency could be obtained by incorporating CdSe as sensitizer into the TiO 2 nanotube arrays via pulse electrodeposition technique. [ABSTRACT FROM AUTHOR]

High density and vertically aligned zinc oxide nanorod arrays (ZnO NRs) have been prepared directly on indium-doped tin oxide (ITO) substrates via two-steps preparation: sol-gel spin coating and hydrothermal process. The nanostructured ZnO was characterized for its morphology, crystalline structure and optical properties by using field emission scanning electron microscopy (FESEM), X-ray diffractometry, and ultraviolet-visible spectroscopy respectively. In addition, the photoeletrochemical (PEC) properties were investigated through photocurrent measurements. The ZnO NRs/ITO had wurtzite-structured (hexagonal) ZnO and preferred growth along (0001) direction. When the growth time was 4 h, ZnO NRs/ITO showed impressive photoresponse. The PEC analysis verified that the ZnO NRs gave better photocurrent response and photoconversion efficiency with approximately 42 times greater than seed layer. [ABSTRACT FROM AUTHOR]