New composite photocatalysts based on complex oxides (Bi2WO6, Bi2MoO6, CsNi0.25W1.75O6 and CsMn0.25W1.75O6) and poly(methyl methacrylate) (PMMA) was synthesized. The effect of PMMA on the change in the amount of active radicals produced by the initial powders under visible was studied. Their photocatalytic activity in the process of methylene blue degradarion and a decrease in the toxicity of a dye solution was shown. Photocatalysis in the presence of the complex oxides in an aqueous dispersion of methyl methacrylate (MMA) was used to initiate radical (co)polymerization due to the formed hydroxyl radicals. The surface of the catalysts before and after the polymerization process has been studied using the XPS method. The antibacterial activity of the composites was measured. However, the results of the experiment showed that all the composite samples used in this study did not have antibacterial properties both under dark and light exposure.