The utilization of metals and metal oxides as photocatalysts is a common method for treating dye contamination. Titanium dioxide nanoparticles (TNPs) are well known for their effectiveness as a photocatalyst in ultraviolet regions, while the inclusion of silver nanoparticles (AgNPs) can improve the photocatalytic properties of the nanocomposite materials in visible light. However, the TNPs and AgNPs are difficult to collect for reuse in water treatment due to their limited dispersion. Henceforth, this work recommended a novel photocatalyst based on hydrotalcite Mg−Al, magnetic Fe3O4 nanoparticles (FNPs), AgNPs, and TNPs prepared using the co‐precipitation method. Additionally, organic silane was first time used as a coupling agent to combine the components together. Consequently, the obtained products were applied for the degradation of methylene blue (MB) under natural sunlight. The characteristics of the synthesized nanocomposites were determined using infrared spectroscopy, vibrating‐sample magnetometer, X‐ray diffraction, dynamic light scattering, and scanning electron microscopy methods. The degradability of MB under sunlight was investigated using ultraviolet‐visible method. Moreover, the antibacterial activity and cytotoxicity of these nanocomposites has been tested and discussed.