Preparation of TiO2 Continuous Fibers with Oxygen Vacancies and Photocatalytic Activity

Abstract

TiO2 continuous fibers were prepared by a modified sol-gel method combined with centrifugal spinning and different heat treatment processes. The prepared fibers were characterized by TG-DSC, XRD, SEM, N2 adsorption-desorption and XPS. The photocatalytic degradation of X-3B aqueous solution was used as a probe reaction to evaluate their photocatalytic activities. The results indicated that heat treatment in steam was conductive to the rapid nucleation of anatase nanocrystal and could effectively suppress the anatase-rutile transformation. Compared with samples calcined in air, products heat treated in steam were long fibers with oxygen vacancies and abundant mesoporous structures, which enhanced their photocatalytic activities. The fibers with a high specific surface area of 87.6 m2·g−1 and the largest pore volume of 0.24 cm3·g−1 were obtained when heat treated at 400°C in steam. The sample exhibited the best photocatalytic activity and the removal rate of X-3B was 99.5% after 90 min under visible light irradiation.