Unraveling the Photocatalytic Performance of La2O3 Nanoparticles for the Degradation of Six Organic Dyes
来源：ACS Publications
Lanthanum oxide (La2O3) nanoparticles stand out as promising photocatalysts due to their remarkable stability and photocatalytic properties. In this study, La2O3 nanoparticles were synthesized via a hydrothermal method and explored how varying calcination time (3 and 5 h) influences their structural, morphological, optical, and catalytic properties. X-ray diffraction (XRD) confirmed stable hexagonal structure, with crystallite sizes increasing from 32.79 to 45.49 nm, while UV–vis absorption studies revealed that increasing calcination time led to a gradual decrease in bandgap energy from 4.6 to 4.4 eV, making the material more effective at utilizing light for pollutant degradation. When tested against a range of organic dyes, La2O3 nanoparticles calcinated for 5 h exhibited the highest degradation efficiencies, due to their improved crystallinity and enhanced charge carrier movement. The photocatalytic process followed first-order kinetics, and recyclability tests showed that the nanoparticles retained their efficiency over multiple cycles. Radical scavenger tests confirmed that hydroxyl radicals (•OH) and superoxide radicals (•O2–) were the dominant reactive species involved in dye degradation, affirming the key mechanism behind the observed photocatalytic performance. These results highlight how fine-tuning calcination time can significantly enhance La2O3’s potential, making it an eco-friendly solution for wastewater treatment.Photocatalysis, leveraging the unique capabilities of nanomaterials such as La2O3, provides a transformative solution. By degrading harmful organic dyes and other pollutants, photocatalysts derived from La2O3 provide an environmentally friendly, energy-efficient, and economical solution for treating industrial wastewater, contributing to the advancement of sustainable water resource management.