Alumina/TiO2/hydroxyapatite interface nanostructure composite filters as efficient photocatalysts for the purification of air

作者：Nasr Esfahani Mojtaba^*; Fekri Sahar

来源：Reaction Kinetics, Mechanisms and Catalysis, 2012, 107(1): 89-103.

DOI：10.1007/s11144-012-0457-x

• Sol-gel process
• Nanostructure
• TiO2
• Apatite
• NOx
• Photo catalytic oxidation

Alumina/TiO2/Apatite interface nanostructure composite filters have been developed for air purification. It was shown that these filters can efficiently absorb and decompose organic species which are suspended in air. To prepare the filters, TiO2 nanopowder was dispersed in titanium sol in 30 and 70 g/L concentrations, and the prepared mixture was deposited on the porous alumina body by dip-coating. Then, the calcined nanostructure composite TiO2-TiO2 was soaked in a simulated physiological solution (SBF) at 37 A degrees C. The surface morphology, surface area, crystalline structure and crystallite sizes of the films were investigated by SEM, EDS, BET, and XRD. The photocatalytic activity of the composite filters, as well as the effect of the TiO2 nanopowder concentration in the titania sol and soaking time in SBF were also evaluated through the degradation of nitrogen oxides (NO (x) ) as one of the dominant causes of air pollution in the car exhaust gases. SEM and XRD results showed that immersion in SBF forms a layer of carbonate-containing apatite on the TiO2 layer. The results showed that increasing nanopowder TiO2 concentration increases the NO (x) oxidation rate. The prepared alumina/TiO2/HA filter can be used to remove CO gas with the absorption mechanism, as an interesting CO degradation performance (about 95 %) was observed in the alumina/TiO2/HA filter after soaking into SBF for 20 days. However, it could not significantly alter the concentrations of other car exhaust pollutants (SO2 and C (x) H (y) ).

• 出版日期2012-10