Antimony-doped cerium ferrite: a robust photocatalyst for the mitigation of diclofenac potassium, an emerging contaminant

Abstract

The present work reports an improvement in the photocatalytic performance of cerium ferrite (CeFeO3) via doping of antimony (Sb) towards the photodegradation of toxic pharmaceutical pollutant i.e. diclofenac potassium. The variable concentrations of Ce1-xSbxFeO3 (x = 0.00, 0.01, 0.03, 0.05, 0.06, 0.07, 0.09) were prepared using facile co-precipitation route and subsequently characterized for their optical, structural, morphological, and dielectric properties using various analytical techniques. It was established that an increase in Sb concentration as dopant (up to x = 0.07) reduced the optical band gap from 2.74 eV to 2.42 eV making it suitable candidate for photodegradation. The X-ray diffraction (XRD) pattern revealed orthorhombic phase of synthesized materials with small crystallite sizes in the range of 15.28 to 2.42 nm. The high value of dielectric constant (3.5841 × 106) for Ce0.93Sb0.07FeO3 with small loss tan (3.1208) compared with the CeFeO3 indicated its ability as photocatalyst to effectively store charges to make them utilize for photocatalytic activity. The degradation efficiency of Ce0.93Sb0.07FeO3 reached 86.7% in 120 min of light irradiation under optimized conditions (pH = 4, catalyst dosage = 15 mg, primary drug concentration = 5 mg/L). Ce0.93Sb0.07FeO3 was also found to be stable over its multiple catalytic runs as only 6.5% decline in degradation efficiency was observed in recyclability test. The remarkable performance of antimony doped cerium ferrite against the removal of persistent pharmaceutical pollutant indicated its strong potential to be used in wastewater treatment in future works.