@article{23076,
  keywords = {Relative humidity, Aldehyde, Clay, Hectorite, P25, Photocatalyst},
  author = {Daria Kibanova and Mohamad Sleiman and Javiera Cervini-Silva and Hugo Destaillats},
  title = {Adsorption and photocatalytic oxidation of formaldehyde on a clay-TiO2 composite},
  abstract = {<p>We investigated the adsorption capacity and photocatalytic removal efficiency of formaldehyde using a hectorite-TiO<sub>2</sub> composite in a bench flow reactor. The same experimental conditions were applied to pure TiO<sub>2</sub> (Degussa P25) as a reference. The catalysts were irradiated with either a UVA lamp (365&nbsp;nm) or with one of two UVC lamps of 254&nbsp;nm and 254&nbsp;+&nbsp;185&nbsp;nm, respectively. Formaldehyde was introduced upstream at concentrations of 100–500&nbsp;ppb, with relative humidity (RH) in the range 0–66% and residence times between 50 and 500&nbsp;ms. Under dry air and without illumination, saturation of catalyst surfaces was achieved after ∼200&nbsp;min for P25 and ∼1000&nbsp;min for hectorite-TiO<sub>2</sub>. The formaldehyde uptake capacity by hectorite-TiO<sub>2</sub> was 4.1 times higher than that of P25, almost twice the BET surface area ratio. In the presence of humidity, the difference in uptake efficiency between both materials disappeared, and saturation was achieved faster (after ∼200&nbsp;min at 10% RH and ∼60&nbsp;min at 65% RH). Under irradiation with each of the three UV sources, removal efficiencies were proportional to the Ti content and increased with contact time. The removal efficiency decreased at high RH. A more complete elimination of formaldehyde was observed with the 254&nbsp;+&nbsp;185&nbsp;nm UV source.</p>},
  year = {2012},
  journal = {Journal of Hazardous Materials},
  volume = {212-212},
  pages = {233-239},
  month = {04/2012},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/22226716},
  doi = {10.1016/j.jhazmat.2011.12.008},
}