Photocatalytic oxidation of nitric oxide over AgNPs/TiO2-loaded carbon fiber cloths.

Series of AgNPs/TiO2-loaded carbon fiber cloth (CFC) composites were prepared by incorporation of pristine TiO2 and three AgNPs-modified TiO2 additives onto the surface of four commercial CFCs. AgNPs/TiO2 photocatalysts were synthesized by the wet impregnation method, including NaBH4 reduction of silver ions. The silver content in the modified photocatalyst was assessed by inductively coupled plasma optical emission spectrometry (ICP-OES) as well as XRD analysis. It can be indicated that silver was successfully reduced to Ag nanoparticles what was confirmed by UV-Vis/DRS as well as XRD methods. The photocatalytic activity of the AgNPs/TiO2-loaded CFCs was evaluated during the photocatalytic oxidation (PCO) tests of nitric oxide (NO) acting as a model air contaminant under UV light. It was found that the highest NO removal rate was observed for the AgNPs/TiO2-loaded CFC material containing 3.70 wt% of AgNPs. Modification of TiO2 with AgNPs stabilized the photocatalytic efficiency of the composites during 5 as well as 24 consecutive NO photooxidation cycles. It was also concluded that the presence of AgNPs was a key factor responsible for hindering NO2 formation.