Facile synthesis of Er-doped BiFeO3 nanoparticles for enhanced visible light photocatalytic degradation of tetracycline hydrochloride

In the present work, Er-doped BiFeO3 (BFO) nanoparticles (Bi(1−x)ErxFeO3, where x = 0.00, 0.01, 0.03, 0.05) containing different concentrations of Er dopants were successfully prepared through a facile sol gel method. The crystalline structure, morphological features, and chemical compositions of the obtained samples were examined by a variety of characterization techniques, and these samples were then used as photocatalysts for the photocatalytic removal of tetracycline hydrochloride (TC) upon visible light. The Er doping could significantly improve the optical absorption capability of the BFO especially in visible light range, and could also boost the photocatalytic activity of the BFO for TC removal. Among all the prepared photocatalysts, the Er3%-BFO sample yielded the highest photocatalytic efficiency of 75.8% for TC removal, which was nearly 2.78 times that of pure BFO. On the basis of the photocurrent response, electrochemical impedance spectra, and photoluminescence emission results, the contributions made on the significantly boosted photocatalytic activities of Er-doped BFO could be reflected on the following aspects: (i) the improved spectral absorption especially in visible light region, (ii) the promotion of photoinduced charge separation and migration, and (iii) the suppressed recombination probability of photogenerated electron–hole pairs. The present work demonstrates the feasibility of employing rare earth doping to develop highly efficient BFO-based photocatalysts for the photocatalytic removal of antibiotics.