This work focalises on the extraction of cellulosic fibres from Nerium oleander. The extracted fibres (EC) were functionalised with polyethyleneimine (PEI) and nano-zero-valent copper (nZVCu). The cellulosic substrates were analysed using scanning electron microscope, Fourier transform infrared, thermogravimetric analysis/differential thermogravimetric analysis, and X-ray diffraction (XRD). The EC/PEI/nZVCu nanocomposite demonstrated a wide surface distribution of nZVCu. The XRD pattern of the extracted cellulose demonstrated three main peaks positioned at 15.4°, 22°, and 34.8° which were attributed to (1 1 0), (2 0 0), and (0 4 0) lattice planes of the crystalline cellulose I. The high residual weight (46.46%) noticed for the EC/PEI/nZVCu nanocomposite approved the chemical functionalisation of the cellulosic substrate with inorganic and organic agents. The EC/PEI/nZVCu nanocomposite was applied for the catalytic reduction of methylene blue solution using sodium borohydride (NaBH4) as a reducing agent. The decolourisation result was affected by several experimental factors including NaBH4 concentration, initial methylene blue concentration, time, and temperature. A complete decolourisation was achieved after 8 min of reaction (pH = 6, C0 = 40 mg/L, NaBH4 = 1 M, T = 20°C). The low calculated Ea value (6.2 kJ mol−1) confirmed the effectiveness of the prepared catalytic system in decolourisation. The catalytic system was non-spontaneous, endothermic, with a reduced disorder.
Jabli et al. (Fri,) studied this question.