Gd and Zr Co-Doped BiFeO3 Magnetic Nanoparticles for Piezo-Photocatalytic Degradation of Ofloxacin
Xuan Liu, Jie Chao, Feifei Guo, Liangliang Chang, Xinyang Zhang, Wei Long, Zengzhe Xi
Abstract
Addressing the limitations of poor piezoelectric photocatalytic activity and insufficient magnetic recovery in pure BiFeO3 nanoparticles, Gd and Zr co-doped BiFeO3 nanoparticles were synthesized via the sol-gel method. The structural characterization revealed a rhombohedral-to-orthorhombic phase transition with reduced grain size (~35 nm) and lattice distortion due to dopant incorporation. An XPS analysis confirmed Fe3+ dominance and oxygen vacancy enrichment, while optimized BGFZ9 exhibited enhanced remanent magnetization (0.1753 emu/g, 14.14 increase) compared to undoped BFO. The synergistic piezo-photocatalytic system achieved 81.08% Ofloxacin degradation within 120 min (rate constant: 0.0136 min−1, 1.26 higher than BFO) through stress-induced piezoelectric fields that promoted electron transfer for ·O2−/·OH radical generation via O2 reduction. The Ofloxacin degradation efficiency decreased to 24.36% after four cycles, with structural integrity confirmed by XRD phase stability. This work demonstrates a triple-optimization mechanism (crystal phase engineering, defect modulation, and magnetic enhancement) for designing magnetically recoverable multiferroic catalysts in pharmaceutical wastewater treatment.