Tuning the visible-light-driven photocatalytic properties of multi-decorated TiO2 by noble metals towards both propionic acid and NOx

Propionic acid (PA), as one of the leading organic compounds responsible for odors-polluted areas, and NOx, with various environmental and health impact, have been one of the main reasons for the poor air quality in outdoor and indoor areas. Semiconductor-assisted photocatalysts permit to degrade different types of pollutants without secondary pollutants production. In this work, PA and NOx degradation has been investigated in the presence of both primary (Ag) and secondary (Au, Pt, and AuPt) noble metals-modified micro-sized TiO2 photocatalysts under LED irradiation.[1] The synthesis has been done through cheap and sustainable approach, based on the use of noble metals-enriched wastewaters. It was demonstrated that the synergistic effect between the metals in multi-decorated photocatalyst, as well as the presence of metallic impurities (mainly copper) in the wastewater used for the preparation of the photocatalysts, have a beneficial effect on the materials’ photoactivity, as they prevent e-/h+ recombination, and enhance the lifetime of the photogenerated charges.