High-efficiency decontamination of pharmaceutical wastewater from γ-In2Se3/MoS2/graphene composite driven by broad-spectrum absorption spanning ultraviolet to near-infrared irradiation

Abstract

Antibiotic contamination in water bodies poses a grave challenge to both environmental sustainability and human health. Among the emerging technologies for pharmaceutical pollutant decontamination, photocatalysis has garnered significant attention due to its superior efficiency. This study introduces a groundbreaking wide-spectral responsive γ-In₂Se₃/MoS₂/graphene composite system, fabricated through van der Waals interactions. To evaluate its photocatalytic activity, the system was tested against tetracycline (TC) degradation, demonstrating an impressive removal efficiency of 91% within 100 minutes. This performance far surpasses that of comparable systems γ-In₂Se₃ (60%) and γ-In₂Se₃/MoS₂ (79%). The superior efficiency is attributed to the synergistic effects arising from broad-spectrum absorption spanning ultraviolet to near-infrared wavelengths and optimized carrier separation kinetics, leading to a notable increase in photocatalytic activity. Furthermore, reactive oxygen species identification confirmed that surface-bound h⁺ and ·O₂⁻ are the primary intermediates governing the degradation process. The proposed degradation pathway for TC not only delineates the chemical transformation mechanisms but also underscores the significant reduction in wastewater toxicity post-catalytic treatment. Notably, the catalyst retains its excellent performance even after four consecutive cycles. These findings highlight the immense potential of this composite system for addressing antibiotic pollution in water resources and pave the way for future advancements in sustainable photocatalysis research.