Stable Ta2O5 nanotubes decorated by PbS by the SILAR method for photocatalytic dye degradation

Tantalum oxide Ta2O5 nanotubes (NTs) were prepared by electrochemical anodization and were decorated with lead sulfide nanoparticles PbS (NPs) by Successive Ionic Layer Adsorption and Reaction commonly known as the SILAR method. The PbS NPs/Ta2O5 NTs were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM-EDX), Transmission Electron Spectroscopy (TEM), Photoluminescence (PL), and Diffuse Reflectance Spectroscopy (DRS). An increasing number of SILAR cycles applied on this substrate were shown to induce a variation in the optical properties and the bandgap of PbS NPs/Ta2O5 NTs. The bandgap went from 3.83 eV for bare Ta2O5 to 3.4 eV for Ta2O5 NTs decorated with 10 PbS SILAR cycles. Ten SILAR cycles were seen to correspond to 2.7 wt% and 1.4 M percentage of the decorated Ta2O5 NTs. Ten SILAR cycles were required to drive the fastest degradation kinetics of the Black Amido mediating Ta2O5 (NTs)-PbS NPs under light irradiation. However, longer SILAR cycles were not seen to faster the degradation kinetics due to light screening. The prepared nanotubes exhibited high stability over 5 photocatalytic reuse cycles.