Zulhadjri, Nurul Pratiwi, Yulia Eka Putri, Rahmayeni, Nandang Mufti, Ramli, Vienna Saraswaty, Suriati Sufian
Lanthanum-doped zinc ferrite (ZFLa) nanoparticles were synthesized via a hydrothermal method, utilizing Uncaria gambir Roxb leaf extract as a capping and stabilizing agent. X-ray diffraction (XRD) and Le Bail refinement confirmed a cubic spinel structure formation with an Fd-3m space group. Fourier-transform infrared spectroscopy (FTIR) analysis indicated a shift of the vibration mode of the tetrahedral site to a higher frequency with increasing lanthanum concentration. Raman spectroscopy revealed an additional peak in the A1g mode at 605 cm−1 for ZnFe1.9La0.1O4 (ZFLa10), suggesting the formation of an inverse spinel structure due to a complex cation distribution at the tetrahedral sites. Scanning electron microscopy (SEM) showed that all samples exhibited spherical grains at the nanoscale, with particle size decreasing as lanthanum concentration increased. UV–Vis diffuse reflectance spectroscopy (DRS) indicated band gap energies within the visible light range (1.84 to 1.86 eV). Brunauer-Emmett-Teller (BET) analysis confirms the increased surface area and pore diameter due to the introduction of La3+ ions, the specific surface area and pore diameter were 96.76 m2/g and 8.78 nm for ZFLa0, and 106.21 m2/g and 10.49 nm for ZFLa10, respectively. The adsorption percentage increased from 17.59 % for ZFLa0 to 55.56 % for ZFLa10. Photocatalytic investigations demonstrated that all catalysts exhibited good activity in degrading Direct Red 81 dye, with ZFLa10 showing the highest photocatalytic activity under direct sunlight, achieving up to 99.68 % degradation of the dye. Stability tests demonstrated remarkable durability, with ZFLa10 maintaining 90.20 % degradation efficiency after five cycles, establishing it as an excellent photocatalyst candidate. © 2024 Elsevier B.V.
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Andalas, Padang, 25163, Indonesia; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang 5, Malang, 65145, Indonesia; Department of Physics, Universitas Negeri Padang, 25131, Indonesia; Research Center for Applied Microbiology, Badan Riset dan Inovasi Nasional, Indonesia; Department of Chemical Engineering, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak, Malaysia
