Synthesis of TiO2/ramie fiber composite and its photocatalytic effect on the degradation of a dye in wastewater

TiO2 was prepared by a hydrothermal method. It was chemically combined with carboxymethyl cellulose prepared from biodegradable ramie fiber to obtain the TiO2/ramie fiber composite. The TiO2/ramie fiber composites were characterized by an X-ray diffractometer, an environmental scanning electron microscope, and a Fourier-transform infrared spectra. The results indicate that TiO2 is chemically combined with ramie fiber, and it can be reused more than five times without obvious TiO2 loss. The photocatalytic performances of TiO2 and TiO2/ramie fiber composite used to degrade both a methyl orange (MO) anionic dye and a rhodamine B (RB) cationic dye solution indicate that the photocatalytic activities of TiO2 for the degradation of the above described solutions are greatly improved when the TiO2 is dispersed on ramie fiber. When 0.5 g of the TiO2/ramie fiber composite is added to a dye solution for 3 h, the degradation rates for the initial concentrations (20 mg/L of MO and 12 mg/L of RB) are greater than 90 %. The photocatalytic degradation of MO can be described as a zeroth order reaction.