Morphology regulated Bi2WO6 nanoparticles on TiO2 nanotubes by solvothermal Sb3+ doping as effective photocatalysts for wastewater treatment

Bi2WO6 particles with controlled morphologies of nanosheets, microroses and microspheres were obtained by the solvothermal Sb(3+ )doping, and the Bi2WO6 deposition on TiO2 nanotubes with different Sb3+ doping amounts influenced the solar absorption, photocurrent and photocatalytic ability. The roselike BWO-10 photoelectrode showed more excellent photocurrent (0.24 mA/cm(2)), outstanding photo-voltage (-0.24 V) and interface resistance than those of other samples under visible light irradiation. The BWO-10 photoelectrode also exhibited excellent photocatalytic activity, and 80.58%, 77.23%, 99.06% and 93.84% of rhodamine B (RhB), methyl orange (MO), methylene blue (MB) dye molecules and Cr (VI) ions could be removed. The active species and photocatalytic mechanism for the pollutant treatment were explored based on the free radical capture experiments. The optimization of morphology and energy band structure was the main reason for the dramatical improvement of photocatalytic performances. The work illustrates the advance of metal ion doping in semiconductor photocatalysts, which provides the effective strategy for the preparation of photocatalysts with high photocatalytic performances in wastewater purification. (C) 2019 Elsevier Ltd. All rights reserved.