Preparation of a novel nano-TiO2 photocatalytic composite using insoluble wood flour as bio-carrier and dissolved components as accelerant

Abstract

Using NaOH/ urea solution to partially dissolve wood flour, a novel nano-TiO2 photocatalytic composite was prepared by hydrothermal method with insoluble wood flour as bio-carrier and dissolved components of wood flour as accelerant. SEM results showed that the control sample prepared without adding titanium sulfate consisted of insoluble wood flour and still possessed unbroken fibers after hydrothermal treatment. The control sample prepared without wood flour addition was only composed of TiO2 micro-particles. With assistant of the dissolve components of wood flour, nano-TiO2 with the size of 50−300 nm was well assembled on the surface of insoluble wood flour. The composite is composed of anatase TiO2 and insoluble wood flour and possess high specific surface area. The absorption edge of composite extended to the visible light range. The composite exhibited high removal rate of methylene blue, up to 97.7% within 120 min. This performance was even better than commercial TiO2 (P25) with the rate of 81.8%. The reused performance of the composite retains removal rate of 90.7% even after 5 cycles. The environment-friendly nano-TiO2 photocatalytic composite can be very useful for degrading refractory organic pollutants.