Titanium dioxide–graphene oxide composites with different ratios supported by Pyrex tube for photocatalysis of toxic aromatic vapors

Abstract

Titanium dioxide–graphene oxide (TiO2–GO) composites with different ratios of GO to TiO2 were synthesized using a colloidal blending process and evaluated for their heterogeneous photocatalytic purification of toxic aromatic vapors using a Pyrex tube reactor. Both SEM and FTIR demonstrated the presence of a carbon component in the as-prepared TiO2–GO composites. Unlike unmodified TiO2, the TiO2–GO composites showed a light-absorbance shift into the longer wavelength regions, indicating band-gap narrowing. The time-series ratios of outlet to inlet concentrations of selected aromatic vapors determined using the TiO2–GO composites under visible-light and UV exposure were lower than or similar to those obtained using unmodified P25 TiO2, suggesting that the TiO2–GO composites had superior photocatalytic activity to P25 TiO2 for degradation of vaporous aromatic pollutants. In addition, the time-series ratios of outlet to inlet concentrations determined using the TiO2–GO composites under both visible-light and UV irradiation decreased, as the ratio of GO to TiO2 increased from 0.01 to 0.10, while they increased as the ratio increased from 0.10 to 0.15, suggesting the presence of an optimal GO to TiO2 ratio. Overall, TiO2–GO composites supported by Pyrex tubes could be utilized effectively for degradation of toxic vaporous aromatic pollutants.