Supramolecular vesicles as nanoreactors enable green synthesis of ultrasmall silver oxide nanoparticles for visible-light photocatalysis.

The uncontrolled release of synthetic organic dyes into aquatic systems poses significant environmental and health risks due to their toxicity, persistence, and resistance to biodegradation. Among these, cationic dyes such as malachite green (MG) and crystal violet (CV) are particularly hazardous, underscoring the need for sustainable and efficient remediation strategies. Here, we present a green supramolecular approach for the in situ synthesis of ultrasmall silver oxide nanoparticles (Ag2O NPs) within self-assembled vesicular architectures formed by a hydrazine-functionalized naphthalene diimide (NDI-Am) derivative. The synthesis proceeds under ambient conditions, eliminating the need for external reducing agents, toxic chemicals, or elevated temperature. Mechanistically, the confined vesicular microenvironment enables localized hydroxide ion generation, facilitating controlled nucleation and growth of uniformly distributed Ag2O NPs (∼8 nm). The resulting Ag2O NPs/NDI-Am nanohybrid exhibits excellent photocatalytic performance under visible light irradiation, achieving degradation efficiencies of 97% for MG and 90% for CV following pseudo-first-order kinetics. This enhanced activity is attributed to the narrow band gap of Ag2O promoting efficient charge separation and reactive oxygen species generation. Overall, this work establishes a sustainable and potentially scalable platform for the design of supramolecularly engineered photocatalysts for wastewater treatment and environmental remediation.