Silver-Paper/Poly(vinyl Alcohol) Catalyst: Dip and Flow Mode Deployment with Plasmon Activation

A facile in situ method is developed to fabricate a metal-paper/polymer nanocomposite to leverage the advantages of homogeneous and heterogeneous catalysis. Silver nanoparticle-filter paper/poly(vinyl alcohol) (Ag-FP/PVA) nanocomposite system is deployed for the efficient catalytic degradation of methylene blue (MB), a toxic synthetic dye, in aqueous medium. Ag-FP/PVA acts as a dip catalyst for the reaction with high stability and recyclability. Even without the addition of any external reducing agent like borohydride, the nanocomposite paper provided a TOF of 1.85 × 10¹⁷ molecules g⁻¹ s⁻¹. The Ag-FP/PVA catalyst is also deployed in a flow mode, enabling the degradation of MB with an enhanced TOF of 2.32 × 10¹⁷ molecules g⁻¹ s⁻¹ with a flow rate of 8.5 mL min⁻¹. The process carried out in presence of light with different wavelengths and intensities demonstrates the critical role of plasmon activation in enhancing the catalytic efficiency. Scanning Kelvin probe microscopy analysis reveals a lower work function for the Ag-FP/PVA under ambient light compared to the dark condition, providing an important insight into the catalytic degradation of MB. This study illustrates a general approach to developing cost-effective paper-based nanocomposites for effective catalysis in dip or flow mode, and gaining a mechanistic understanding of the process.