title: Reduction of carbon dioxide on jet spray formed titanium dioxide surfaces.
abstract: The photocatalytic reduction of carbon dioxide (CO(2)) on jet spray formed titanium dioxide (TiO(2)) was studied using light-emitting diode (LED) illumination centred at a wavelength of 388 nm. In addition, the photocatalytic reduction of CO(2) under soft X-ray irradiation was also studied. Specifically, the experiments examined the reduction of CO(2) in a gaseous and liquid-gas system using residual gas analysis mass spectrometry. A photochemical reduction of CO(2) was observed over a course of 250 min, with transformation to a major product, C(2)H(3)O(-) (ethenolate), until equilibrium was reached. The product was observed to be surface stabilised, with it reverting back to CO(2) over the course of 100 min without illumination. A proposed free radical mechanism is presented for the formation of this product. A similar effect to that of UV illumination is also observed to occur under the influence of soft X-rays, which presents a potentially significant alternative method for the activation of TiO(2).
authors.affiliation: Interface Analysis Centre, Oldbury House, 121 St. Michael's Hill, Bristol BS2 8BS, United Kingdom. james.macfarlane@bristol.ac.uk
authors.forename: J W
authors.initials: JW
authors.lastname: MacFarlane
authors.forename: T B
authors.initials: TB
authors.lastname: Scott
mesh_terms: D000393:Air Pollutants / Q000737:chemistry* / Q000528:radiation effects; D002245:Carbon Dioxide / Q000737:chemistry* / Q000528:radiation effects; D002384:Catalysis; D053758:Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction; D010782:Photolysis; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014965:X-Rays
chemical_list: D000393:Air Pollutants; D002245:Carbon Dioxide; C009495:titanium dioxide; D014025:Titanium