Lanthanum-iron binary oxide nanoparticles: As cost-effective fluoride adsorbent and oxygen gas sensor

In the present work, novel lanthanum-iron binary oxide nanoparticles are used as adsorbents for fluoride removal from aqueous solution and oxygen gas sensor. The lanthanum-iron binary oxide nanoparticles were synthesized using co-precipitation method and sintered at a temperature of 100 degrees C, 450 degrees C, and 900 degrees C for 2 h. The material, optical and electrical properties of the nanoparticles were investigated by the instrumental characterization of high-resolution scanning electron microscope and high-resolution transition electron microscope to determine the structure, vibrating sample magnetometer which confirmed the superparamagnetic behavior, BET surface area analysis to affirm the mesoporous nature, X-ray photoelectron spectroscopy to confirm the oxidation states, X-ray diffraction, Fourier transform infrared spectroscopy, and I-V analysis, respectively. The adsorption of fluoride carried out in batch system, the experimental data were analyzed using isotherm and regeneration studies. The results demonstrated that the LIBONs sintered at 100 degrees C showed exceptional fluoride removal with maximum adsorption of 14.49 mg g(-1) at pH 6.5 +/- 0.5. The regeneration percentage of 80% was obtained after fifth cycle. The nanoparticles sintered at 900 degrees C rendered good sensitivity and response/recovery characteristics towards 50% of oxygen at operating temperature of 350 degrees C.