Photocatalytic degradation of cooking fume on a TiO2-coated carbon nanotubes composite filter.

A TiO2/MWCNTs/Al2O3/NF (TiO2 nanoparticles/multi-walled carbon nanotubes /Al2O3-modified nickel foams) composite filter was prepared through grown of MWCNTs upon Al2O3-modified nickel foams using chemical vapor deposition (CVD) method and then coated TiO2 nanoparticles onto MWCNTs using dip-coating method. The MWCNTs forms a network-like structure on the surface layer of composite filter. The BET surface area of TiO2/MWCNTs/Al2O3/NF composite filter is more than 375 times higher than that of the pristine nickel foam. The degradation performance of oil particles was evaluated. Under optimized reaction conditions, 90% of the oleic acid on the filter was decomposed after 25 h. In addition, the effect of reaction temperature and light intensity were studied. Increased reaction temperature and light intensity were found to significantly improve the degradation rate and restrain the formation of refractory product. Furthermore, a parallel reaction kinetic model was adopted for degradation of oleic acid on the composite filter. The composite filter can reduces the accumulation of oil particles on the filter and the energy consumption of the filter. This approach proposes a new way to treat the cooking fume emission at residential building roofs.