Bifunctional metavanadate promoted chitosan/cassava biopolymer films with photo-switchable wetting properties: unveiling the surface restructuring mechanism.

Biopolymer films derived from starch and chitosan were soaked in vanadium salt solutions to produce vanadium metallopolymer films. Visible light irradiation induces significant color shifts from yellow to green due to changes in the oxidation state of vanadium. The material was observed to undergo dramatic structural changes upon incorporation of vanadium, with further restructuring occurring after visible light illumination.

Enhanced Antibacterial Activity at Ag-Cu Nanojunctions: Unveiling the Mechanism with Simple Surfaces of CuNPs-on-Ag Films.

Deposition of CuNPs on silver film gives rise to the formation of active Ag-Cu interfaces leading to dramatic enhancements in antibacterial activity against . Transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDAX) analyses reveal that CuNPs are covered in a thin CuO shell, while X-ray photoelectron spectroscopy measurements (XPS) reveal that the Ag film samples contain significant amounts of AgO. XPS analyses show that the deposition of CuNPs on Ag films leads to the formation of a photoactive AgO-CuO heterostructure.