Carbon nanofibres as substrates for the preparation of TiO2 nanostructured photocatalysts

Carbon nanofibres from different origins have been used as substrates for the preparation of TiO2/CNF hybrid materials and TiO2 nanofibres. The influence of the CNFs on the final properties of the prepared materials is analysed. The results show that the crystallinity of the CNFs used is the parameter that most influences the quality of the TiO2 deposition. CNFs with low-to-moderate crystallinities are suitable for preparing TiO2/CNF materials with a uniform TiO2 coating and with interesting properties: high surface areas, close to 400 m2/g, and anatase phase. Additionally, TiO2 nanofibres maintaining such anatase phase and an important surface area can be prepared from these uniform TiO2/CNF hybrids by burning the CNFs. These TiO2/CNF hybrid materials and TiO2 nanofibres, having larger surface areas than similar materials prepared in a previous work using carbon nanotubes, are analysed as photocatalysts for the oxidation of propene at low concentration (100 ppmv) under UV light irradiation. The results show interesting photocatalytic activities (better for the hybrid materials than for the TiO2 nanofibres), that can be further enhanced increasing the surface area and/or reaching a suitable anatase/rutile proportion.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► TiO2/CNF hybrids and TiO2 nanofibres can be obtained using CNFs as substrates. ► CNFs with low-moderate crystallinity permit to get uniform TiO2 deposition on them. ► Removal of CNFs by burning leads to TiO2 nanofibres with a central hollow. ► TiO2/CNF hybrids possess larger photocatalytic activity than TiO2 nanofibres. ► Oxidation of the CNFs previous to TiO2 deposition increases photoactivity.