Variable band-gap Sr-hexagonal ferrites on carboxylated graphene oxide composite as an efficient photocatalytic semiconductor

In this study, Sr Gdx Fe(12 –x) O19 nanostructures (x= 0, 0.2(3% Gd), 0.4 (6%Gd),0.6(9%Gd), 0.8 (12%Gd)) were synthesized by self-combustion sol-gel method and then calcined at the temperature of for 3 h. This compound was then composited with functionalized graphene oxide (GO) for the photocatalytic degradation of Enrofeloxacin. FESEM, EDS, XRD, and FTIR analysis were employed to investigate the particle size, elemental composition, morphological structure, functional groups determination and structural composition of the samples. VSM, BET-BJH, TGA-DTA, DRS and zeta potential analysis were also used to assess the magnetic properties, surface area, thermal stability, band-gap determination and suspension stability of the specimens, respectively. For evaluation of performance, photocatalytic degradation of Enrofeloxacin (an antibiotic that is widely used for domestic animals) is performed. The results showed that the 3% and 6% Gd-doped composites had the highest efficiencies in the photocatalytic reaction.This research reports the successful synthesis of SrGdxFe12-xO19/GO-COOH composites and its characterization by various techniques. The results indicated that SrGdxFe12-xO19/GO-COOH composite can be employed as an applicable candidate for the photodegradation of ENR antibiotic drug from pharmaceutical industry effluent as well as the water resources. Analysis of the results by statistical software based on the response surface method showed that the prolongation of the radiation time and catalyst mass, as well as pH reduction, can enhance the efficiency of ENR photodegradation. By increasing the pollutant concentration, however, the degradation efficiency declined.