Plasmonic–semiconductor coupling in Ag NPs@Cu-V2O5 hybrids for integrated SERS detection and visible-light photocatalysis

Integrating pollutant detection and degradation into a single material platform is highly desirable for the efficient treatment of dye-contaminated wastewater. However, simultaneously achieving sensitive detection and efficient photocatalytic activity remains challenging because these functions involve distinct interfacial processes. In this work, an Ag NPs@Cu-V 2 O 5 hybrid was prepared through wet-chemical synthesis and calcination of Cu-V 2 O 5 , followed by ultrasonic coupling with preformed Ag nanoparticles. Cu incorporation modulated the local electronic environment of V 2 O 5 , while the supported Ag nanoparticles provided plasmonic SERS-active sites. XPS binding-energy shifts were consistent with interfacial electronic redistribution, FDTD simulations revealed pronounced local-field amplification around the Ag nanoparticles, and energy-level analysis indicated accessible interfacial charge-transfer pathways under 532 nm excitation. Using colorless, non-resonant 4-MBA as a control probe, the hybrid produced a higher Raman response than the Ag NP reference under equivalent Ag loading, indicating that the enhancement was not solely dependent on the molecular pre-resonance behavior of MB. The hybrid enabled MB detection down to 1 × 10⁻⁹ mol L⁻¹ , with good spatial uniformity and approximately 80% signal retention after 28 days. After correction for dark adsorption, it achieved an MB degradation efficiency of 82.3% after 60 min of visible-light irradiation and exhibited higher photocatalytic activity than pristine V 2 O 5 and Cu-V 2 O 5 . These results demonstrate a plasmonic–semiconductor platform that integrates SERS sensing and photocatalytic remediation through Ag-induced local-field amplification, Cu-related electronic modulation, and Ag/Cu-V 2 O 5 interfacial interactions.