Combination of one-dimensional TiO2 nanowire photocatalytic oxidation with microfiltration for water treatment

This paper proposed the fabrication of two different diameter one-dimensional TiO2 nanowires, 10 nm TNW10 and 20–100 nm TNW20, via hydrothermal process using different alkaline sources. TNW10 and TNW20 were used as photocatalysts for the degradation of humic acid (HA), the major natural organic matters (NOMs) in surface and ground water, followed by microfiltration. The evaluation of photocatalytic activities of them showed that TNW10 was superior to the commercial P25 TiO2 while TNW20 was as good as P25. The membrane filtration verified that the two types of nanowires could be completely reclaimed. The membrane fouling caused by TNW10 and TNW20 was much less than that of P25 due to more porous cake and less pore plugging. No apparent decrease on their photocatalytic activity was observed in repeated reuse experiments. These one-dimensional TiO2 nanowires would provide a new route for the combination of photocatalytic oxidation and membrane filtration for water treatment.