Congo red removal by lanthanum-doped bismuth ferrite nanostructures

Phase-pure lanthanum (La)-doped bismuth ferrite (La-BFO) nanostructures with La contents of 0-15% were synthesised by a wet chemical method. The structural, morphological, elemental, and optical characteristics confirmed the phase purity and granular morphology of synthesised La-BFO. Zeta potential indicated a significant increase of surface charge of La-BFO with increasing doping content. The La-BFO nanostructures were used for adsorption of anionic Congo red (CR) from aqueous solution under different physio-chemical conditions. A removal efficiency of 95% was achieved in 135 min. The experimental results suggested that the increasing doping concentration of La increased the adsorption capacity and removal efficiency due to an electrostatic interaction between negatively-charged La-BFO nanostructures and the protonated amine group of CR. The adsorption capacity was strongly influenced by the initial pH of the CR solution.

Automated summary

Phase-pure La-doped bismuth ferrite (La-BFO) nanostructures were successfully synthesised using a wet chemical method. The La-BFO exhibited excellent adsorption performance for anionic Congo red, with an increasing doping concentration of La leading to higher adsorption capacity and removal efficiency. The initial pH of the solution strongly influenced the adsorption capacity.