Biopolymer-reinforced cellulose aerogels supporting green-synthesized silver nanoparticles for robust antibacterial...

The development of multifunctional and sustainable catalysts is essential for mitigating both chemical pollutants and microbial threats in wastewater. Herein, we report a green approach for synthesizing silver nanoparticle (AgNPs)-embedded cellulose aerogels using durian shell (DS) biomass. DS extract was employed as a natural reducing and stabilizing agent for AgNPs synthesis, while the residual biomass was valorized into cellulose (Ce) via microwave-assisted treatment. The extracted Ce was crosslinked with chitosan (Cs), alginate (Al), and gelatin (Ge) to form porous aerogel supports (ACeCs, ACeAl, and ACeGe), enabling uniform AgNP incorporation under light-assisted conditions. All AgNP-loaded aerogels exhibited ultra-high porosity (>95 %) and low bulk density (<0.2 g/cm³), which significantly enhanced reactant diffusion and catalyst recoverability. Among the composites, Ag/ACeCs exhibited the highest catalytic efficiency, achieving complete reduction of p-nitrophenol (PNP) to p-aminophenol within 10 min, with a rate constant of 0.39 min^-1 at 1.00 g/L dosage and a PNP/NaBH₄ ratio of 1/250. This catalyst also facilitated efficient degradation of o-nitrophenol, m-nitrophenol, and methyl orange, while demonstrating vigorous antibacterial activity (>99.99 % inhibition) against E. coli and S. paratyphi A. The aerogels retained performance over five cycles and were easily recovered via vacuum filtration. This work offers a scalable, circular approach to converting agro-waste into high-performance catalysts for integrated water purification and environmental sustainability.