(Co, Ag, Ni, Cd, Mn, Cr)-doped PbS photo-catalyst: sonochemical-assisted synthesis of magnetite nanocomposites applicable for elimination of toxic pollutants

Magnetite (Fe3O4) and PbS nano-crystals were prepared by hydrothermal and sonochemical-assisted method in an inexpensive and bio-compatible environment. Secondly metal (Co, Ag, Ni, Cd, Mn, Cr)-doped PbS nanostructures and Fe3O4/metal-doped nanostructures were made via wet chemical method. The influence of various metal doping on the shape and size of the magnetic nanomaterials was examined. Nanomaterials were characterized by XRD, SEM, TEM and FT-IR spectroscopy. VSM approves the magnetic property of the magnetite and nanocomposites. The results show superparamagnetic properties of nanomaterials. Under sonochemical irradiation, cavitation is formed in solvent where the bubbles are firstly formed, secondly grow, and finally collapse. This bubble production can make hot spots about 5000 C and 1800 kPa, which are applicable in various bond breaking and preparations of dispersions. It is a sound field with 20 kHz frequency that has many applications in the preparation of magnetic and photo-catalyst nanostructures. The photo-catalyst properties of nanocomposites were investigated via photo-degradation of three azo dyes acid blue, acid black and acid brown under ultraviolet irradiation in times less than 60 min.