Synergistic effect of CuxOy-NPs/TiO2-NTs heterostructure on the photodegradation of amido black staining

Abstract

TiO2 nanotube arrays have been extensively investigated for optoelectronic applications besides their excellent photocatalytic activity. The present work aims to study TiO2 nanotubes (NTs) fabricated with the anodization of Ti substrates. CuxOy nanoparticles (NPs) were deposited on TiO2 nanotubes (NTs) using the Successive ionic layer adsorption and reaction (SILAR) method. The obtained nanocomposite was used in the photocatalytic degradation of synthetic organic pollutants (amido black). Particular emphasis was focused on the effect of the morphological, optical, and structural properties of the CuxOy (i.e., the number of SILAR cycles) on the photocatalytic efficiency of the formed heterostructure. The morphological structural and optical properties were investigated by scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction analysis (XRD), UV–vis spectroscopy, and photoluminescence (PL), respectively. The results show the formation of TiO2 anatase NTs decorated with CuO and Cu2O NPs. The density and size of the Cu2O NPs were found to increase with the number of SILAR cycles, whereas the energy band gap is narrowed by 0.7 eV. Photocatalytic tests demonstrate that at 15 SILAR cycles, the Cu2O.CuO-NPs/TiO2-NTs heterostructure exhibits the highest photocatalytic performance, reaching 94 % of amido black degradation under UV irradiation (256 nm) for 90 min. The experimental data modeling indicates that the faster the degradation, the better the photocatalytic performance; i.e., the reaction rate k = 0.025 min-1. The current study highlights the potential of CuxOy decorated TiO2 substrates as efficient photocatalytic systems for degrading hazardous organic pollutants.