OICC Press International Journal of Nano Dimension 2228-5059 11 1 2024 02 07 Adsorption and photodegrading of Methylene Blue by using of BaLaxGdxFe12-2xO19 (x=0.2, 0.4, 0.6 and 0.8)/PANI nanocomposites 10.57647/ EN Fatemeh Abdollahi Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran. 1111-1111-1111-1111 Mohammad Yousefi Department of Chemistry, Yadegar-e Imam Khomeini (RAH) Shahr-e Rey Branch, Islamic Azad University, Tehran, Iran. Malak Hekmati Department of Organic Chemistry, Faculty of Pharmaceutical chemistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Ana Khajehnezhad Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran. Seyyed Salman Seyyed Afghahi Department of Engineering, Imam Hossein University, Tehran, Iran. Journal Article 2024 02 07 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 (R2) value which was about 0.98, proved that the photocatalytic reactions followed the Pseudo-first order kinetic.