Structural, morphological, and optical properties of Ag-doped TiO${}_2$ thin-film over fiber optic substrate for sensing applications

Ag-doped TiO${}_2$ (rAg/Ti, r${}_{1-3}$ = 2, 4, 6 wt%) is synthesized by a hydrothermal technique. Different characterizations, that is, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) analysis, photoluminescence (PL) spectra analysis, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), energy dispersive X-ray analysis (EDX), and Brunauer-Emmett-Teller (BET) analysis, are conducted to study the utility of the developed thin-film material as a sensing medium over the fiber substrate. The as-prepared material is hydrothermally deposited over the optical fiber to construct a fiber optic sensing probe. The optical properties of TiO${}_2$ are simulated theoretically by MATLAB simulation that reveals that optical absorption appears at the wavelength of 763 nm. The initial performance of the rAg/Ti-based optical fiber is investigated with the amine group in the range of 500-1500 ppm and a satisfactory response is found toward ethylenediamine (EDA) analytes with average sensitivity (S${}_{av}$, in %) as 41.81 at 1200 ppm. (© 2021 Wiley‐VCH GmbH)