A New Generation of Surface Active Carbon Textiles As Reactive Adsorbents of Indoor Formaldehyde

Highly porous carbon textiles were modified by impregnation with urea, thiourea, dicyandiamide, or penicillin G, followed by heat treatment at 800 °C. This resulted in an incorporation of nitrogen or nitrogen and sulfur heteroatoms in various configurations to the carbon surface. The volume of pores and, especially, ultramicropores was also affected to various extents. The modified textiles were then used as adsorbents of formaldehyde (1 ppmv) in dynamic conditions. The modifications applied significantly improved the adsorptive performance. For the majority of samples, formaldehyde adsorption resulted in a decrease in the volume of ultramicropores. The enhancement in the adsorption was linked not only to the physical adsorption of formaldehyde in small pores but also to its reactivity with sulfonic groups and amines present on the surface. Water on the surface and in challenge gas decreased the adsorptive performance owing to the competition with formaldehyde for polar centers. The results collected show that the S- and N-modified textiles can work as efficient media for indoor formaldehyde removal.