Hierarchical nano Fe(0)@FeS doped cellulose nanofibres derived from agrowaste – Potential bionanocomposite for treatment of organic dyes

Abstract Biological macromolecule namely cellulose nanofiber was synthesized from agrowaste sugarcane bagasse. Further, hierarchical nano Fe(0) – FeS was anchored on cellulose nanofibers to obtain CNF-Fe(0)@FeS and it was characterized by various spectral techniques. Formation of FeS2 was confirmed by high resolution TEM and XPS techniques. Anchoring on cellulose nano fibers prevented agglomeration of nanocomposite and furthermore, coating of FeS2 helped in the preservation of Fe(0). Thus the prepared nano composite was very effective in the removal of cationic Methylene blue (MB) dye and anionic Congo red (CR) dye with a maximum adsorption capacity of 200.0 and 111.1 mg/g respectively. Both MB and CR dye followed Pseudo second kinetic with regression coefficients >0.98. Especially for MB dye, it was observed that kinetics of adsorption/degradation was very fast and within 3 min, peak at 370 nm disappeared and 70% reduction in intensity was observed at 660 nm. Further FTIR and XPS revealed evidence for the degradation of adsorbed dye molecules. Considering its high adsorption capacity, degradation potential and ease of preparation using agrowaste makes CNF-Fe(0)@FeS a promising sorbent for the treatment industrial dye effluents.