Silver nanoparticles embedded in borate-crosslinked guar gum-bacterial cellulose composite dip catalyst for efficient...

4-Nitrophenol (4-NP) is a dangerous environmental pollutant that has considerable ecological and health risks. Hence, the creation of eco-friendly technologies to remove or degrade 4-NP is of great importance. In the current work, a straightforward method was used to synthesize a multifunctional dip catalyst based on a guar gum and bacterial cellulose hybrid matrix doped with silver nanoparticles. Bacterial cellulose-guar gum‑silver nanocomposites were synthesized using different concentrations of silver ions (1.0, 2.5, and 5.0 mM). The synthesized nanocomposites were characterized using X-ray diffraction spectroscopy, scanning electron microscopy/energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller measurements. The XRD spectra confirmed the formation of face-centered cubic silver nanoparticles with crystallite sizes ranging from 3.6 to 7.7 nm. SEM measurements indicated the presence of silver nanoparticles within the bacterial cellulose-guar gum hybrid matrix. BET measurements indicated that the surface area was affected upon the incorporation of silver nanoparticles. Among the synthesized nanocomposites, bacterial cellulose-guar gum-Ag2.5 was found to exhibit the best catalytic activity towards the reduction of 4-NP to 4-aminophenol with complete conversion within 4 min with an apparent rate constant kapp = 0.630 ± 0.004 min^-1. The dip catalyst also showed good reusability without the release of silver during the repeated cycles. Besides, the toxicity tests showed good biocompatibility. The flexibility of the dip catalyst makes it easier to handle, separate, and reuse the catalyst without the need to recover it. This demonstrates the potential of BC-GG-Ag biopolymer nanocomposites as efficient and green catalysts for the removal of water pollutants.