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This work demonstrated the absence of surface terminal hydroxyl groups plays a key role in the photocatalytic oxidation of low concentration volatile organic compounds. Probed by 1 H MAS NMR spectroscopy, we showed the synthesis of bare and F-TiO 2 nanoparticles with undetectably low content of terminal hydroxyl groups (TiOH) on the surface of TiO 2 could be obtained through a sol–gel process. The characterization results by N 2 adsorption, XRD, HRTEM, Raman, and XPS show that the bare TiO 2 and F-TiO 2 have almost identical bulk and surface structural properties. The photocatalytic activity was evaluated by photocatalytic oxidation of acetaldehyde and ethanol. Due to the absence of terminal TiOH in the bare TiO 2 and F-TiO 2 , both materials exhibit 100% photodegradation of acetaldehyde and ethanol. No deactivation was observed during the experimental period of 8 days. The activities surpassed the photodegradation performance of the benchmarking Aeroxide P25 TiO 2 under similar conditions (93%). On the bare TiO 2 , only stoichiometric CO 2 production was observed and no detectable by-product existed in the product stream, resulting in no expanded off-odor problems. On the contrary, ethanol photodegradation on F-TiO 2 produced minor acetaldehyde as a by-product, but the amount of acetaldehyde produced was still lower than that produced on Aeroxide P25. |
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