Complete mineralization of surfactant from aqueous solution by a novel sono-synthesized nanocomposite (TiO2–Cu2O) under sunlight irradiation

[Display omitted] •A new method has developed for the synthesis of TiO2–Cu2O nano-composite by ultrasonic bath.•Nanocomposite showed a high optical absorption in the visible range and high activity in mineralization of SDBS.•Nanocomposite with 5% TiO2 exhibited better photocatalytic activity than Cu2O, TiO2 alone or other composites.•Mineralization of SDBS in solution completed after 90min and on the surface of the catalyst after 240min.•Degradation obeyed the first-order kinetics and the adsorption obeyed the Langmuir model. In this study, a new method has developed for the synthesis of TiO2–Cu2O nano-composite with high optical absorption in the visible range and high photocatalytic activity in mineralization of sodium dodecyl-benzenesulfonate (SDBS) in an ultrasonic bath with low intensity at 40kHz. The results of EDAX, TEM and XRD confirmed the purity, crystallinity and the structure of the nanocomposite particles with the size less than 10nm. Ultrasound played a key role in the formation of nanocomposite with highest photocatalytic activity in mineralization of SDBS under sunlight. The degradation of SDBS by sunlight irradiation showed that the extent of mineralization depends on the operating conditions. In addition, the TiO2–Cu2O that contained 5% (mole ratio) TiO2 exhibited better photocatalytic activity than either Cu2O or TiO2 alone or other composites with different mole ratios. So that, the mineralization percentage of SDBS in the solution reached to 100% after 90min and the mineralization on the surface of the catalyst was completed after 240min. The data obtained from the degradation experiments fit the first-order kinetics and the adsorption obeyed the Langmuir model.