Synthesis of amino acids-functionalized iron oxide nanoparticles for response surface methodology-based statistical optimization of photocatalytic degradation of methylene blue.

Here, amino acids-functionalized iron oxide nanoparticles were synthesized by utilizing the co-precipitation methodology. The synthesized nanoparticles (including alanine, valine, and phenylalanine-functionalized nanoparticles) were characterized by utilizing several analytical techniques. Acquired outcomes validated the successful formation of amino acid-functionalized iron oxide nanoparticles. The X-ray diffraction and scanning electron microscopy indicated that phenylalanine-based iron oxide nanoparticles exhibited high crystallinity and better fabrication, respectively, in comparison with other amino acids. This was attributed to the development of high hydrophobic interactions of the phenylalanine with the iron oxide nanoparticles. The photocatalytic efficacy of the iron oxide nanoparticles against the methylene blue was investigated by implementing two different optimization strategies (i.e., traditional one-variable-at-a-time kinetics and advanced response surface methodology). The experiment performed by using phenylalanine-functionalized iron oxide nanoparticles as a photocatalyst under optimized conditions revealed that the highest efficacy of 92.91 and 97.12% was obtained by using the one-variable-at-a-time and response surface methodology approaches, respectively, indicating that the latter approach is more effective for the optimization of the understudy reactions. In terms of comparative effectiveness of the reaction parameters, the photocatalyst dose was found to be the most effective emphasizing that special emphasis should be given to this parameter when dealing with the optimization of this reaction on an industrial scale. The total organic carbon analysis further revealed that the mineralization of 90.216% was achieved under optimized reaction conditions. The prepared iron oxide nanoparticles exhibited strong photocatalytic potential for the understudy chemical reaction. [ABSTRACT FROM AUTHOR]