Title: Photocatalytic Nitrate Reduction Under Solar-Simulated Light Using Modified TiO2
Funder
Engineering and Physical Sciences Research Council
Principal Investigator
Co-Investigators
Hutchings, Graham
Miedziak, Peter
Warner, Sarah
Taylor, Stuart
Project Details
Start date: 01/10/2013
End date: 30/09/2017
Abstract
Metal loadings of between 0.3 and 0.4% were found to give the highest weight loadings and this was concluded to be due to an optimum amount of surface coverage by small metal nanoparticles. The catalysts were found to be very selective towards nitrogen with Au catalysts tending to form ammonia at high conversions and Ag catalysts forming nitrite at low conversions. Bimetallic AuAg catalysts were prepared that had higher activities than their mono-metallic equivalents with 100% selectivity to N2. These catalysts were found to be highly reusable.
None of the prepared M-TiO2 catalysts were found to have any visible-only activity for nitrate photo-reduction and the enhancement of photo-activity with the deposition of metals was concluded to be due to increased charge-carrier separation effects.
Attempts were made at visibly-active TiO2 by N-doping but although UV-visible DRS analysis showed a redshift in the adsorption band of these catalysts and XRD found the anatase to rutile ratio to be near ideal no reproducible visible-light activity was achieved.