Synthesis of nano-copper chelated hierarchical biocomposite from eggshell membrane hydrolysate for visible-light-driven dye degradation

Abstract

A green synthesis approach was adopted to synthesize a nano-copper chelated hierarchical biocomposite (nCu-CHB) from an eggshell membrane (ESM) protein hydrolysate. The structural features of the synthesized material were investigated through XRD, FTIR, and XPS, while its morphological features were investigated using SEM, EDX, and TEM. The surface area, thermal stability and optical properties were evaluated using BET, TGA, and UV-vis spectroscopy, respectively. The results demonstrated that nCu-CHB exhibits a porous and wrinkled morphology with uniformly distributed copper nanoparticles, ranging from 5–9 nm. The material showed a surface area of approximately 14.25 m² g⁻¹ and an optical band gap of 2.0 eV. The eco-friendly biocomposite demonstrated excellent visible-light photocatalytic performance, achieving up to 98.09% degradation of methylene blue (MB) within 90 min at neutral pH. Kinetic studies indicated that the degradation behavior followed pseudo-first-order kinetics (k = 0.0432 min⁻¹, R² = 0.9975). This work presents a promising approach for developing multifunctional biocomposite materials from ESM hydrolysate for the eradication of hazardous pollutants from water.