Tryptophan-assisted Eu@ZnO/rGO nanocomposites as an efficient photocatalyst for degradation of Tetracycline

In the present study, highly crystalline europium-doped zinc oxide decorated on reduced graphene oxide nanocomposites (Eu@ZnO/rGO NCs) was successfully synthesized via a simple precipitation method using an ethanolic solution of tryptophan. The synthesized NCs was systematically authenticated in terms of phase, crystallite size, structure, chemical state, bandgap energy and morphology using different spectroscopic and microscopy techniques. The photocatalytic study of the synthesized NCs was performed against the degradation of tetracycline (TC) under visible light at room temperature. The results demonstrated a significant TC degradation efficiency of 59.14% within 150 min. Kinetic analysis suggested TC degradation followed first-order kinetics, with a rate constant (k) of 0.00650 min −1 and a correlation coefficient (R 2 ) of 0.9148. Furthermore, the synthesized NCs exhibit an excellent free radical scavenging potential with 95.67 ± 0.42% (IC 50 =28.55 µg/mL) at a concentration of 400 µg/mL. Overall, these results highlight the capabilities of Eu@ZnO/rGO NCs as a promising material for addressing broader environmental and biological issues.