Synthesis of lanthanum phosphate-carbon nanoparticles using hydrothermal method and its application for lead ion removal

Abstract

Given the wide range of uses for lanthanum phosphate nanoparticles, a simple and effective production technique is desperately needed. In this work, phytic acid as a source of phosphate and tannic acid as a polyphenol rich material were used as green reagents in a simple hydrothermal method to fabricate lanthanum phosphate-carbon (LaPO4-C) nanoparticles. Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX), X-Ray Diffraction (XRD) analysis, Fourier Transform Infrared (FT-IR) Spectrophotometry, and Transmission Electron Microscopy (TEM) were used to characterize the synthesized LaPO4-C nanoparticles. The outcomes demonstrated the effective synthesis of LaPO4-C nanoparticles with diameters ranging from 30 to 40 nm. The fabricated LaPO4-C NPs were then used as adsorbent for elimination of lead ion (Pb2+) from water samples. The best adsorption conditions were found to be pH 5–6, an adsorbent dosage of 8 mg, and a contact period of 40 minutes (more than 90 % removal percentage for 50 mg L-1 Pb2+). The interpretation of different isotherm models also show that the adsorption of Pb2+ ions onto the LaPO4-C NPs is a monolayer phenomenon (Langmuir isotherm) with a maximum adsorption capacity of 333.33 mg g-1. Moreover, the adsorption kinetic models represents that the pseudo first order kinetic is the appropriate model for prediction of kinetic results.