Facile synthesis of ternary TiO₂ NP/Rh & Sb-codoped TiO₂ NR/titanate NT composites photocatalyst: Simultaneous removals of Cd²⁺ ions and Orange (II) dye under visible light irradiation (Λ ≥ 420 nm)

In this study, rhodium and antimony doped nanorod (RS-TONR) was prepared by a molten salt solid state chemical reaction, and TiO₂ nanorod and titanate nanotube (RS-TONR/TiNT) composite photocatalyst was synthesized by a hydrothermal method for different reaction times. The structural and chemical analyses of nanomaterials were performed by FE-SEM, XRD, UV-DRS and surface BET characterizations. The XRD and HR-TEM data confirmed that the as-synthesized material had mixed phase of TiO₂ nanorod and Titanate nanotube (RS-TONR/TiNT). The photocatalytic activity of the composite photocatalyst was observed over the degradation of Orange (II) dye under visible light irradiation. Acid treatment and copper loading was conducted to enhance the surface property of RS-TONR/TiNT sample. The formation of TiO₂ nanoparticle with anatase phase was observed by TEM and XRD analysis. The TEM mapping data also confirmed that copper oxide nanoparticles were well dispersed on the surface of titanate nanotubes. These dispersed nanoparticles were observed by XPS and STEM characterizations. The higher removal efficiency of Cd²⁺ ions was observed over the acid treated and untreated Cu3-TNP/TiNT/RS-TONR in the presence of Orange (II) dye. A higher photocatalytic activity of acid treated and Cu3-TNP/TiNT/RS-TONR was simultaneously obtained in the presence of cadmium ions during the degradation of Orange (II) dye.