Abstract The pure conjugated polyarylene azomethine (CPAA) and its nanocomposites (CPAA-TiO 2 ) with different concentrations of TiO 2 nanoparticles were successfully prepared by in-situ technique and analyzed by different advanced techniques. XRD has confirmed the structural properties and crystallinity of (CPAA) and nanocomposites. The SEM clearly shows that the (CPAA) is uniform and homogeneous, with tightly connected aggregate layers in shape. However, the amount of TiO 2 in the nanocomposites greatly affects their morphology, revealing structural differences and indicating a reaction between (CPAA) and TiO 2 , especially at a higher concentration of 5% TiO 2 . A new composite of (CPAA) was introduced and the photocatalytic effect for MB was studied. The removal efficiency of (pure-CPAA) over MB dye under simulated sunlight was 62%. However, (CPAA-TiO 2 1%) destroyed 90% of MB dyes. It was discovered that the low band gap of (CPAA-TiO 2 1% (2.84 eV)) accelerates high electron–hole recombination, increasing photocatalytic activity.