<![CDATA[Synthetic dyes such as methyl orange are classified as persistent pollutants that are difficult to degrade biologically, thus requiring effective and sustainable treatment technologies. This study develops a photocatalytic membrane based on polyurethane (PU) synthesized from avocado seed oil, hexamethylene diisocyanate (HDI), and polyethylene glycol (PEG) for immobilizing TiO₂ nanoparticles. PEG was used as a dispersing additive to prevent TiO₂ agglomeration and enhance the membrane's hydrophilicity. XRD characterization revealed that the TiO₂ nanoparticles were predominantly in the anatase phase, with a characteristic diffraction peak at 2θ = 25.2740°. FTIR analysis confirmed the successful synthesis of PU through the identification of characteristic functional groups, including –NH, –C=O (urethane carbonyl), and –C–O–C (ether) from PEG, as well as Ti–O and Ti–O–Ti vibrations indicating the presence of TiO₂. SEM observations showed a semi-globular morphology of TiO₂ particles that were homogeneously dispersed within the PU matrix without significant agglomeration. Photodegradation performance tests under UV-A irradiation (265 nm) at an irradiation distance of 11 cm demonstrated a maximum degradation efficiency of 91.165% at pH 4, with good reusability stability, achieving 91.173% efficiency after repeated cycles. The high effectiveness is attributed to electrostatic interactions between the positively charged TiO₂ surface and negatively charged methyl orange molecules, which accelerate the generation of reactive radical species during the photocatalytic process.]]>
