Dielectric, ferroelectric, optical and photocatalytic properties of Al and Ag-doped strontium hexaferrite (SrFe12O19) synthesized via facile micro-emulsion approach

Abstract

Al and Ag-doped Sr1-xAgxFe12-yAlyO19 (x, y = 0.0, 0.2, 0.4, 0.6, 0.8) nano-materials (NMs) were prepared via a facile microemulsion approach and the effect of doping was appraised based on structural, optical, electrical and catalytic properties. The NMs were characterized by XRD, FTIR and UV-Vis techniques along with ferroelectric and dielectric properties. The NMs structure was hexagonal symmetric with crystallite size in the 23.3–30.2 nm range. The ferroelectric and dielectric properties were affected significantly in response to dopant content. The band-gap (Eg) values of NMs were in the 3.52–2.59 eV range. The photocatalytic efficiency (PCE) of bare strontium hexaferrite (SHF) and Sr1-xAgxFe12-yAlyO19 was evaluated against Methyl Orange (MO) dye (an anionic dye) and Rhodamine B (RhB) dye (a cationic dye) under solar light irradiation. The PCE of SHAF4 was 89%, while it was 52% in the case of SHF whereas for RB, SHF shows 66% and SHAF-4 represents 92% degradation. Pure SHF and SHAF-4 points of zero charge (pHzpc) were found to be 7.09 and 6.9, respectively. The remarkable PCE of the highest doped Sr1-xAgxFe12-yAlyO19 SHAF-4 makes this material a potential photo-catalyst for the removal of toxic dye from wastewater.