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

• NiFe 2 O 4 was successfully synthesized via co-precipitation route. • Various physio-chemical techniques were employed to characterize the prepared samples. • The prepared photocatalysts were used for the degradation of pendimethalin under sunlight. • rGO based nanocomposite showed maximum degradation efficiency. • Gd doping and insertion of rGO sheets help to enhance the photo-degradation ability of nickel ferrite. NiFe 2 O 4 (F-1) and rare earth metal (Gd) doped NiFe 2 O 4 (F-2) were prepared via a co-precipitation approach. Gd-NiFe 2 O 4 @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. NiFe 2 O 4 and Gd-NiFe 2 O 4 showed 48.88 %, and 61.11 % degradation of pendimethalin. Gd-NiFe 2 O 4 @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. [ABSTRACT FROM AUTHOR]