0D/1D Bi2O3@TNTs composites synthesized by the decoration of Bi2O3 quantum dots onto titanate nanotubes: Synergistic adsorption of U(VI) and tetracycline

U(VI) and tetracycline (Tc) are serious contaminants coexisted in wastewater from hospitals. Herein, 0D/1D Bi2O3@TNTs composites are designed and synthesized through the decoration of Bi2O3 quantum dots onto titanate (TNTs) nanotubes to synchronously remove U(VI) and Tc. SEM, TEM, XRD, FTIR, XPS, BET and zeta potential are used to analyze obtained composites, which indicate the successful synthesis of Bi2O3@TNTs with the special 0D/1D morphologies as well as high surface area. Besides, batch adsorption experiments at pH = 5 and T = 25 °C show that the removal efficiency is significantly enhanced with excellent adsorbing capacities (QU(VI) = 347.39 mg/g and QTc = 536.57 mg/g), which is mainly because of the high surface activity by the doping of Bi2O3 and high stability of the 0D/1D framework. Moreover, a S-Dual-model (SDM) model is established for precise and reliable simulating the adsorption isotherms. Finally, a comprehensive synergistic adsorption mechanism for U(VI) and Tc is proposed based on the systematic analysis of XRD, XPS and FT-IR spectra results.