The Superiority of TiO 2 Supported on Nickel Foam over Ni-Doped TiO 2 in the Photothermal Decomposition of Acetaldehyde.

Acetaldehyde decomposition was performed under heating at a temperature range of 25-125 °C and UV irradiation on TiO 2 doped by metallic Ni powder and TiO 2 supported on nickel foam. The process was carried out in a high-temperature reaction chamber, "The Praying Mantis TM ", with simultaneous in situ FTIR measurements and UV irradiation. Ni powder was added to TiO 2 in the quantity of 0.5 to 5.0 wt%. The photothermal measurements of acetaldehyde decomposition indicated that the highest yield of acetaldehyde conversion on TiO 2 and UV irradiation was obtained at 75 °C. The doping of nickel to TiO 2 did not increase its photocatalytic activity. Contrary to that, the application of nickel foam as a support for TiO 2 appeared to be highly advantageous because it increased the decomposition of acetaldehyde from 31 to 52% at 25 °C, and then to 85% at 100 °C in comparison with TiO 2 itself. At the same time, the mineralization of acetaldehyde to CO 2 doubled in the presence of nickel foam. However, oxidized nickel foam used as support for TiO 2 was detrimental. Most likely, different mechanisms of electron transfer between Ni-TiO 2 and NiO-TiO 2 occurred. The application of nickel foam greatly enhanced the separation of free carriers in TiO 2 . As a consequence, high yields from the photocatalytic reactions were obtained.