This study presents the synthesis of a CuO-TiO₂–saponite ternary nanocomposite via a hydrothermal method, designed to efficiently remove bromocresol green dye. Characterization techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy, confirmed significant interactions between metal oxide nanoparticles and the clay mineral matrix. Diffuse reflectance and photoluminescence analyses revealed a narrow band gap and surface defects, such as oxygen vacancies, enhancing the material’s photocatalytic properties. Under UV irradiation, the nanocomposite achieved 83% discoloration of bromocresol green dye within 150 min. The inhibitor studies identified hydroxyl and superoxide radicals as key species in the degradation mechanism. This work underscores the potential of clay-mineral-based nanocomposites, where clay minerals function both as structural support and as enhancers of the semiconductor’s photocatalytic activity.

The magnetic properties of the double perovskites Sm ₂ Mn _{1+ x} Co _{1− x} O ₆ ( x = 0, 0.05, 0.12 and 0.26) were investigated. It was found that the Curie temperature, the lattice parameters and the net magnetic moments increased for increasing amounts of Co. An irreversible behavior was observed by measuring the magnetization after cooling the sample with and without applied magnetic fields ( H ). The temperature below which the irreversibility was observed is H dependent and the data were nicely fit to de Almeida–Thouless lines. The ac magnetic susceptibility was measured for frequencies f in the range 0.03–10 kHz yielding for the shifting in the freezing temperature per decade of f . The spin-dynamics were found to follow a power-law with a product of the critical exponents of about 4.99. The overall results are understood within a framework where the variation in the bonding angle associated to the super-exchange interactions are taken into consideration.