Ultrasound-assisted successive ionic layer adsorption and reaction synthesis of Cu2O cubes sensitized TiO2 nanotube arrays for the enhanced photoelectrochemical performance

In this paper, Cu₂O cubes with high photoelectrochemical activities were deposited on the surface of TiO₂ nanotube arrays by the ultrasound-assisted successive ionic layer adsorption and reaction (SILAR) method. The elemental composition and morphology were characterized by XPS and SEM. The TiO₂ NTs/Cu₂O showed excellent photoelectric conversion and photoelectrocatalytic (PEC) removal of organic dyes and Cr(VI). The results confirmed that the SILAR deposition cycle greatly influenced the visible light response and PEC properties, and the TiO₂ NTs/Cu₂O (6) prepared with 6 SILAR cycles showed the optimal visible light photocurrent (1.08 mA/cm²), visible light photovoltage (−0.044 V/cm²), solar PEC degradation efficiencies of MO (77.62%), RhB (61.83%) and MB (98.30%), and PEC reduction of Cr(VI) (97.16%). The TiO₂ NTs/Cu₂O photoelectrodes would show prospective applications in solar cells and waste-water treatment due to the significantly enhanced photoelectrochemical performance.