Emerging pollutants and industrial waste dyes are significantly increasing with the development of new industries. The development of nano-composites are getting more attention in this regard due to their unique properties. Here in barium M-hexaferrites with novel composition BaFe11(SnMg)(0.25)Nd0.5O19 (SMN) was synthesized as heterogeneous photo-Fenton-like system for the degradation of Methylene Blue (MB). The synthesized SMN nano-particles (NPs) were characterized with numerous techniques, including Thermo-gravimetric analysis (TGA), X-ray Diffraction (XRD), Brunauer-Emmet-Teller (BET), Transmission Electron Microscopy (TEM), Scanning electron microscopy (SEM), Optical properties (UV), Fourier transform infrared spectra (FTIR) and magnetometer (VSM). The factors affecting the degradation reaction such as photocatalyst (SMN) dosage, H2O2 concentrations, UV irradiation and pH were scientifically explored. The photo-Fenton-like activity of SMN-NPs revealed high degradation (98.89%) and mineralization (83%) after 140 min in SMN-NPs + H2O2 + UV irradiation system within a wide range of pH. Moreover, good stability and recycling ability of SMN-NPs was achieved. HPLC/GC-MS analysis revealed the degradation pathways of MB and the intermediates were mineralized into CO2 and H2O. The outcomes revealed that SMN-NPs were promising for emerging industrial dyes removal. (C) 2019 Elsevier Inc. All rights reserved.