Titania nanosheet photocatalysts with dominantly exposed (001) reactive facets for photocatalytic NOx abatement

The particular role of reactive facets TiO2 on photocatalytic NOx removal was systematically explored. The photo selective catalytic reduction (photo-SCR) of NOx was studied using titania nanosheet photocatalysts. The titania nanosheets were synthesized by hydrothermal method with titanium n-butoxide (TBOT) and hydrofluoric acid (HF). The synthetic pathway of transformation from TBOT (Ti precursor) to TiO2 nanosheet was clearly revealed that TiOF2 is the intermediate during the hydrothermal process. The NO conversion of titania nanosheets was found to be higher than the conversion of commercial P25 and TiO2 synthesized by the sol-gel method. Moreover, one of the titania nanosheets, FT1.5, displayed the highest efficiency of NOx removal at 393 K, but there was a trade-off relationship between NO conversion and NO2 selectivity. Our results suggest that the optimal synthetic process for highest efficiency of TiO2 nanosheet in photocatalysis is to use TBOT and HF with the F/Ti atomic ratio = 1.5 (FT1.5) at 453 K for 24 h. In summary, the synthesized TiO2 nanosheet exhibits great potential to be applied in NOx abatement.