Synthesis and characterisation of Fe3O4 at MPTMS at Au nanocomposite by sol–gel method for the removal of methylene blue

New magnetic nanocomposite core-shell–shell Fe₃O₄ at 3-mercoptopropyltrimethoxysilan (s) at Au has been synthesised by the sol–gel method. First magnetite nanoparticles are synthesised by co-precipitation method, then the obtained particles are coated by MPTMS coating with the sol–gel method. At final step, gold nanoparticle has been used to coat Fe₃O₄ at MPTMS. New magnetic nanocomposite has been characterised by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and vibrating sample magnetometer, UV–vis spectroscopy. The new nanocomposite has been studied for its efficiency in adsorption of methylene blue (MB) as a model for azo paints which has been widely used in aquatic solutions of textile industry. The adsorption test has been carried out at various contact time of adsorbent and dye, temperature and stirring speed under visible light. The results indicate that the adsorption capacity of MB dye rises by the increase in the temperature, stirring speed and the contact time between MB and adsorbent. This nanocomposite easily separated from the solution with help of week magnetic field. Therefore this new adsorbent could be regarded as a very good adsorbent for MB removal.