Hydrothermal synthesis of Bi2WO6/mesoporous TiO2 nanocomposites and their adsorptive properties

The adsorption performance characteristics of nano-Bi2WO6, mesoporous TiO2, and a variety of Bi2WO6/mesoporous TiO2 nanocomposites for RhB (rhodamine B) were examined using a hydrothermal technique. The synthesis of lamellar Bi2WO6 nanomaterials, mesoporous TiO2 nanomaterials, and layered mesoporous Bi2WO6/ mesoporous TiO2 nanocomposites was confirmed using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and nitrogen adsorption/desorption studies. The test results show that the orthogonal crystalline Bi2WO6 nanomaterial, anatase TiO2 nanomaterial, and Bi2WO6/TiO2 nanocomposite material were prepared; the Bi2WO6 material consisted of a nanosheet with a thickness of approximately 10 nm; and the TiO2 nanomaterial had a mesoporous structure formed by the accumulation of small spherical approximately 5-nm particles. After the two nanomaterials were composited they formed a layered mesoporous structure. The specific surface area of the sheet Bi2WO6 nanomaterial was 29.7 m(2) .g(-1), and the specific surface area of mesoporous TiO2 nanomaterials was 156.5 m(2).g(-1). The composite had a specific surface area of Bi2WO6/mesoporous TiO2 nanocomposites that reached a maximum value of 215.1 m(2).g(-1), and a larger pore capacity was obtained. The adsorption rate of the single (by itself) lamellar Bi2WO6 nanomaterial for RhB was 42.08%, the adsorption rate of the single mesoporous TiO2 nanomaterial to RhB was 35.62%, and the adsorption performance of the composite Bi2WO6/mesoporous TiO2 nanomaterials were enhanced, among which the adsorption rate of sample BT-5 for the RhB solution reached 99% in a short period of time, and the maximum adsorption amount reached 111.2 mg.g(-1); the adsorption process of sample BT-5 on RhB was consistent with the quasi-secondary kinetic model. Its adsorption behavior belongs to the typical Langmuir single molecular layer adsorption. Bi2WO6/mesoporous TiO2 nanocomposites have environmentally friendly, efficient, and low-cost adsorption processes for RhB, indicating that the prepared nanoscale adsorbents have great value in the removal of organic dyes in water pollution.