Preparation and characterization of a biopolymer modified by doping with metallic particles, application

Metal oxides with distinct properties can be integrated into a cellulose matrix, providing a promising approach to improve the performance of cellulose materials and expand their applications in photocatalysis. This research focuses on the development of a new biomaterial by incorporating hematite (α-Fe₂O₃) into the crushed leaves of the palm tree Washingtonia filifera, both in their raw form and as cellulose extracted from the same plant. The incorporation of α-Fe₂O₃ was carried out hydrothermally. The palm leaves, extracted cellulose and synthesized composites were characterized by thermal analysis (TG) and FT-IR spectroscopy. FT-IR spectra revealed peaks at 524 and 449 cm⁻¹ in the synthesized material, attributed to the vibrational deformation of the Fe–O bond. In contrast to the TG profile of raw palm leaves, the thermogram of the composite showed single-step degradation at 343 °C, indicating chemical modification of the cellulose matrix and successful incorporation of hematite into lignocellulose. The SEM image showed that the grains of α-Fe₂O₃ are homogeneously incorporated in the matrix. The second part of the study examines hematite (α-Fe₂O₃) functioning as a sensitizer. It was characterized optically with a gap E_g of 1.94 eV and electrochemically, with a flat band potential of − 0.45 V_SCE. The conduction band (− 0.65 V_SCE) is more cathodic than the O₂/O₂^•− level. As an application, the prepared materials were effectively tested in the photocatalytic degradation of Rhodamine B (Rh B, 10 ppm). A reduction of 60% was reached under visible irradiation (23 mW cm⁻²).