Designed growth of porous 2D Nb ₂ O ₅ with Ag nano-particles for differential detection of UV-A and UV-C

Abstract We demonstrate the differential detection of UV-A (ultra-violet 320–400 nm region) and UV-C (100–280 nm) using porous two-dimensional (2D) Nb ₂ O ₅ and additional Ag nano-particle decoration. The 2D Nb ₂ O ₅ , which has band-absorption edge near the UV-A zone, was synthesized by thermodynamic conversion of 2D material NbSe ₂ (Nb ₂ O ₅ has lower Gibbs formation energy than NbSe ₂ ). For the differential detection (to distinguish with UV-C absorption), we decorated the Ag nano-particles on the Nb ₂ O ₅ surface. By coating Ag nano-particles, we can expect (i) a decrease in the area of light absorption by the Ag-coated area, and (ii) an increase of surface plasmon absorption by Ag nano-particles, especially the UV-A region, resulting in strong intensity ratio change UV-A/UV-C.