Dipeptide-functionalized type II heterojunctions: a bioinspired dual functionality for quinalphos detection and photodegradation

Abstract

Quinalphos, a widely used hazardous organophosphorus pesticide, is crucial in agriculture for safeguarding crops and improving yields. However, its persistent toxic residues result in environmental contamination and pose significant health hazards. Developing methods for the efficient degradation of quinalphos continues to be a major challenge. To address this issue, this study introduces the rational design of bioinspired dipeptide (DM2)-capped ZnO, forming type II staggered heterojunctions that utilize the synergistic interaction between DM2 and ZnO towards enhancing photocatalytic performance. This material enables efficient electron transfer due to the heterojunction structure, resulting in efficient photodegradation of quinalphos. The mode of interaction and photodegradation mechanism of quinalphos have been systematically studied, revealing a pseudo-first-order degradation kinetic model, with up to 99% removal efficiency. Degradation intermediates were identified using mass spectrometry analysis, and a comprehensive degradation pathway was proposed. This work highlights the potential of DM2-capped ZnO NPs as an effective and environmentally friendly material for the photodegradation of quinalphos, offering new avenues for sustainable environmental remediation.