Ionic liquid reinforced cellulose nanofiber with iron oxide electrocatalyst

Increased attention has been focused on the preparation of nanoarchitectures for applicability in energy, environmental and biological streams. However, concerns have been raised regarding environmental effects due to the harsh chemicals used in such preparations. To overcome this issue, the present study reports the use of a green solvent, 1-methyl-3-propyl-1H-imidazol-3-ium iodide or [Pmim]I, for the preparation of cellulose nanofiber-iron oxide (CNF-Fe₂O₃) composite. The as-prepared nanofiber composite is characterized with the aid of analytical tools such as X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDX), and X-ray photoelectron spectroscopy (XPS). As a proof-of-concept demonstration, the resulting nanostructure is employed as an electrocatalyst and is compared with the bare CNFs, non-cellulose NFs and a standard RuO₂ catalyst. The results indicate that the CNF-Fe₂O₃ composite achieves a standard current density (j) of 10 mA cm⁻² at only 260 mV compared to 280, 290, and 370 mV for the standard RuO₂, the bare CNFs, and non-cellulose nanofibers (NFs), respectively. These differences become more prominent at a high current density of 100 mA cm⁻², where the CNF-Fe₂O₃ requires only 310 mV, while the CNFs, RuO₂, and NFs consume 360, 370, and 550 mV, respectively.