Rare earth Gd-doped NiFe2O4 @2D layered carbonaceous composite: Synthesis, structural evaluation and photocatalytic parameters studies

Abstract

NiFe2O4 (F-1) and rare earth metal (Gd) doped NiFe2O4 (F-2) were prepared via a co-precipitation approach. Gd-NiFe2O4@rGO (F-3) was prepared via an ultrasonication route for the degradation of pendimethalin under sunlight. The structural confirmation of as-fabricated samples was done via XRD. The Tauc plot of F-1 showed a bandgap energy of 2.79 eV and F-2 exhibited a bandgap energy of 2.63 eV. The optical band gap was lowered due to the presence of rare-earth metal ions. NiFe2O4 and Gd-NiFe2O4 showed 48.88 %, and 61.11 % degradation of pendimethalin. Gd-NiFe2O4@rGO nanocomposite showed the highest degradation efficiency. It exhibited 84.44 % degradation of pendimethalin in 140 min at the rate of 0.01 min−1. The reason for the greater activity is due to the insertion of rare earth (Gd) ions and rGO sheets in the nickel ferrite. The doping with rare earth metal ions lowers the recombination of electrons and holes which was further supported by the addition of carbonaceous material. The surface area of the nickel ferrite was improved by rGO sheets and in turn more active sites were formed on the surface of the catalyst which fastens the rate of reaction.