Title:Efficient Congo Red Degradation in Aqueous Solutions Using Au/Cu@Chitosan-Coated Cotton Fiber-Supported Nanocatalyst: A Promising Approach for the Removal of Contaminants of Emerging Concern
Volume: 22
Issue: 7
Author(s): Ramiz Ahmed, Hafsa Ayaz, Fahim Ullah, Nauman Ali, Amel Yousef Ibrahim, Mir Waqas Alam, Noushi Zaidi and Faheem Shah*
Affiliation:
- Department of Chemistry, College
of Science, King Faisal University, Al-Hofuf, Eastern Province, Al-Ahsa, 31982, Kingdom of Saudi Arabia
Keywords:
Catalysis, chitosan, Congo red dye, cotton cloth, nanoparticles, wastewater treatment, degradation.
Abstract:
Introduction: Industrial effluents containing synthetic dyes pose serious environmental
hazards, necessitating cost-effective and sustainable catalysts for wastewater treatment.
Methods: Cotton fibers were first dip-coated with 1 wt % chitosan, then impregnated with aqueous
Au³⁺/Cu²⁺ salts. In-situ reduction with hydrazine generated bimetallic Au/Cu nanoparticles (NPs) on
the chitosan-coated cotton (Au/Cu@Chi-CC). The catalyst was characterized by SEM, XRD, and
EDX to confirm nanoparticle formation, elemental composition, and morphology.
Results: SEM and XRD confirmed well-dispersed, alloyed Au/Cu nanoparticles, and EDX verified
the expected Au–Cu ratio. Catalytic tests showed a pseudo–first-order rate constant of 0.298 min⁻¹ for
Congo Red degradation. The catalyst strips maintained over 90 % activity after three reuse cycles,
requiring only a rinse with distilled water.
Discussion: The alloyed Au/Cu interface promoted synergistic electron transfer, leading to markedly
higher catalytic activity than monometallic systems. The high-rate constant reflects this enhancement.
Excellent reusability further demonstrates the catalyst’s stability and ease of regeneration, supporting
its practical applicability.
Conclusion: The Au/Cu@Chi-CC nanocatalyst couples low-cost biopolymer support with bimetallic
synergy, delivering rapid dye degradation and excellent recyclability. These attributes underscore its
practicality as an economical, sustainable solution for removing hazardous dyes from industrial
wastewater.
