Photocorrosion of CdS nanorod arrays and fabrication of CdS@TiO2 core@shell nanorod arrays by atomic layer deposition for improved photostability

Abstract

In this manuscript, an interesting phenomenon was found that partially or entirely hollow CdS nanotube arrays (PEH CdS NT) were obtained after photocorrosion of CdS nanorod arrays (NR). The forming process of PEH CdS NT was studied in detail. Afterwards, CdS@TiO2 core@shell NR with controllable TiO2 thickness onto CdS NR were preparated by atomic layer deposition (ALD), and the photostability of CdS@TiO2 core@shell NR was studied. Compared with unmodified CdS NR, the CdS@TiO2-1500 core@shell NR (the thickness of the TiO2 layer was 1500 ALD cycles) exhibited higher photostability within 300 s, which could be ascribed to the TiO2 nanolayer. TiO2 nanolayer can protect CdS NR from photocorrosion because it can effectually transfer the hole and the electron separation from photoluminescence (PL) characteristic. These results suggest that CdS@TiO2 core@shell NR fabricated by ALD are effective in protecting of CdS NR from photocorrosion.

Keywords

• Partially or entirely hollow CdS nanotube Arrays
• Photocorrosion
• CdS@TiO2 core@shell
• Atomic layer deposition