Facile and efficient dye degradation using silver nanoparticles immobilized cotton substrates

Abstract

• Surfactant-free Ag NPs with tunable concentration were fabricated directly on cotton fabric. • The fabricated substrates showed excellent potential for degradation of methylene blue. • Catalytic activity decreased by only 6.3% after using the substrate for five cycles. • The substrate showed excellent shelf-life, with a decrease in activity of only 7.2% after one month’s storage time. We demonstrate the fabrication of silver (Ag) nanoparticles (NPs) directly on cotton fabric by impregnation of Ag ions onto commonly available cotton followed by their reduction. The NP concentration on the substrate can be increased simply by employing higher molarities of the precursor solution. The inductively coupled plasma (ICP) measurements revealed that the Ag loading achieved on a 2 × 2 cm 2 substrate was 1.15 mg for 0.1 M AgNO 3 solution, which increased to 3.65 mg when 0.5 M AgNO 3 solution was employed. The fabricated substrates are excellent for catalytic degradation of methylene blue (MB). Expectedly, the catalytic activity of the substrates increased significantly with an increase in Ag loading. Despite a very primitive and facile fabrication technique, the substrates showed excellent reusability with a decrease of activity of only 6 % after five catalytic cycles. The ICP measurements revealed negligible Ag leaching, on average 0.18 % per each catalytic cycle. Moreover, the drop in catalytic performance was only 7 % after one month of aging. The excellent reusability and shelf-life are due to the strong adhesion of Ag NPs with the cotton substrate owing to the presence of the hydroxyl functional groups. The facile fabrication technique, and excellent catalytic performance, reusability, and shelf-life make these substrates ideal for dye degradation applications.