adsorption and photodegrading of methylene blue by using of bala‌xgdxfe122xo19 (x=0.2, 0.4, 0.6 and 0.8)/pani nanocomposites

In this paper, a series of balaxgdxfe12-2xo19 (x=0.2, 0.4, 0.6 and 0.8)/pani (polyaniline) nanocomposites synthesized for investigating the photocatalytic properties. barium hexaferrite doped with la3+ and gd3+ prepared via a sol-gel auto-combustion method and then the binary nanocomposites fabricated by the in situ polymerization method. (fourier transform infrared) ftir, (x-ray diffraction) xrd, (field emission electron microscopy) fesem and (vibrating sample magnetometer) vsm confirmed the formation of binary nanocomposites. in ftir analysis, the peaks at 431 and 580 cm-1 wavenumbers supported the formation of barium doped hexaferrite. at 1463 and 1554cm-1 wavenumbers, the formations of quinoid and benzenoid rings were observable. the xrd patterns of nanocomposites proved the formation of pani by appearing the amorphous peak at 2θ=23.05 and 26.05 degrees beside the hexaferrite phase. in fesem pictures, the sphere shape of pani masked the whole nanoparticles of hexaferrite. in vsm hysteresis loops, by doping la3+, the saturation magnetization increased to 74 emu. then, by adding non-magnetic part (pani) to the magnetic hexaferrite, the saturation magnetization decreased to 11 emu. the photocatalytic properties of samples performed under the irradiation of uv-vis light. all samples presented the photocatalytic properties. hexaferrites as a semiconductor generated the electron-hole pairs under irradiation. pani prevented the accumulation of electron-hole pairs on the valance band and consequently accelerated the photo-degradation of methylene blue. kinetic studies and calculation of the correlation coefficient (r^2) value which was about 0.98, proved that the photocatalytic reactions followed the pseudo-first order kinetic.