New photocatalysts stimulated by visible light for organic-waste remediation: (La/Ce) and (La/Gd) codoped BiFeO3

• Published in: Journal of materials science. Materials in electronics Vol. 34; no. 36; p. 2290
• Main Author: Alsulaim, Ghayah M.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2023; Springer Nature B.V
• Subjects: Catalysts; Catalytic activity; Cerium; Characterization and Evaluation of Materials; Chemistry and Materials Science; Current carriers; Dyes; Efficiency; Gadolinium; Irradiation; Lanthanum; Materials Science; Optical and Electronic Materials; Organic carbon; Photocatalysis; Photodegradation; Photomicrographs; Sunlight; Xenon lamps
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-023-11671-5

Bi 0.96 La 0.02 Gd 0.02 FeO 3 catalyst revealed a fast photodegradation efficiency for Congo red (CR), acid green 25 (AG25) and Reactive yellow 145 (RY) dyes under sunlight irradiation. Nanocrystalline BiFeO 3 , Bi 0.96 La 0.02 Ce 0.02 FeO 3 and Bi 0.96 La 0.02 Gd 0.02 FeO 3 compositions were synthesized by autocombustion route. The X-ray diffraction peaks of all samples were indexed to single phase of BiFeO 3 with rhombohedral structure without detection of any impurities. The SEM micrographs showed that the incorporation of (La, Gd) ions changes the morphology of BiFeO 3 powder. BiFeO 3 , Bi 0.96 La 0.02 Ce 0.02 FeO 3 and Bi 0.96 La 0.02 Gd 0.02 FeO 3 samples have a broad response to visible light spectrum with measured bandgap energy of 2.23, 2.05 and 2 eV, respectively. The photocatalytic measurements illustrated that the incorporation of (La/Ce) and (La/Gd) ions strongly improved the degradation efficiency of BiFeO 3 towards CR, AG25 and RY pollutants. Bi 0.96 La 0.02 Gd 0.02 FeO 3 catalyst has shown a significant efficiency within 94–97% for degradation of 20 ppm CR, AG25 and RY (100 mL solution, catalyst dose 40 mg) after 35–40 min of sunlight irradiation. Under Xenon lamp, the photocatalytic activity of Bi 0.96 La 0.02 Gd 0.02 FeO 3 catalyst was found to be 97, 98 and 99% for 20 ppm CR, AG25 and RY dyes, respectively. The reusability test for CR dye for six cycles showed that Bi 0.92 La 0.02 Gd 0.02 FeO 3 catalyst has a high stability with initial and final efficiency of 94% and 82%, respectively. The results of the total organic carbon analysis shown a high level of mineralization of RY (94%) and AG25 (95%) dyes after 60 min. The dual separation of the photoexcited charge carriers by (La 3+  + e  → La 2+ )/(Gd 3+  +  e  → Gd 2+ ) into BiFeO 3 leads to remarkable depollution properties towards many organic dyes.