Visible Light- or UV-Activated Carbon Nanotube-TiO2 Composite Nanofibers for Indoor BTEX Purification

摘要

Poly vinyl acetate (PVAc)-supported carbon nanotube (CNT)-TiO2 composite nanofibers (PCTCNs) with different CNT to TiO2 weight ratios were prepared using a combined sol-gel and electrosptnning technique. The photocatalytic performance of the as-prepared PCTCNs for degradation of an indoor concentration level of benzene, toluene, ethyl benzene and o-xylene (BTEX) was evaluated under visible-light or UV irradiation. For comparison, a PVA-supported TiO2 composite nanofiber (PTN) was also investigated for its photocatalytic performance. The characteristics of the PCTCNs and the PTN were determined using scanning electron microscopy and diffuse reflectance UV-visible spectra. For the target compounds, the average photocatalytic degradation efficiencies obtained from PCTCNs were higher than that obtained from PTN. Specifically, the average photocatalytic degradation efficiencies of BTEX obtained from PCTCN-0.056 were 10. 44, 75 and 88 %, respectively, while those obtained from PTN were 4, 11, 30 and 34 %, respectively. Moreover, the PCTCN-0.056 exhibited the highest photocatalytic degradation efficiencies among the as-prepared PCTCNs, although it did not have the highest MWCNT to TiO2 mixing ratio. Similar to the visible-light irradiation conditions, PCTCN-0.056 revealed the highest photocatalytic degradation efficiencies of BTEX under UV irradiation conditions. However, unlike the visible-light irradiation conditions, the photocatalytic performance of certain PTCNs were lower than those of PTN. Taken together, PCTCNs exposed to visible light could reveal superior performance for photocatalytic degradation of toxic indoor pollutants, when appropriate ratios of MWCNT to TiO2 were utilized for the preparation of PCTCNs.