Electrodeposition of CdSe/TiO2 Coaxial Nanocables for Enhanced Photocatalytic Performance and H2 Evolution in Visible Light

Abstract

CdSe/TiO2 coaxial nanocables hetero-structure, with the wall thickness of 20 nm and the external diameter of about 100 nm, was first constructed via a facile templated electrodeposition method. The SEM and TEM results indicate that CdSe nanowires arrays (NWAs) are symmetrically decorated on the inner pore walls of as-obtained TiO2 nanotube arrays (NTAs). In addition, the photoelectrocatalytic (PEC) performances of as-prepared samples were also systematically investigated by UV-Vis absorption spectroscopy. The degradation rate of CdSe/TiO2 coaxial cable to Rhodamine B (RhB) solution reaches 98.71% under visible-light irradiation for 7 h, and still achieves 89.45% after being reused for 6 cycles, suggesting its good reusability and stability. Kinetic analysis shows that the apparent reaction rate constants for TiO2 NTAs, CdSe NWAs and CdSe/TiO2 coaxial cables are 0.15085, 0.17218 and 0.75291 h−1, respectively. Simultaneously, the H2 evolution rate of CdSe/TiO2 coaxial cables is 10-fold and 5-fold enhancement compared with those of TiO2 NTAs and CdSe NWAs within 200 min. The improved PEC performance of CdSe/TiO2 coaxial nanocables can be ascribed to the synergistic effect of TiO2 NTAs and CdSe NWAs. This research demonstrates that CdSe/TiO2 coaxial nanocables have a promising future in industrial and environmental applications.