High porosity silica aerogel thin film to monitoring vanadium: Synthesis, characterization and implementation

Abstract

Sol–gel chemistry is a very unique method for constructing high-performance flexible sensors. Sol-gel silica matrices doped with a controlled amount of sensing agent (dopant) lead to the fabrication of suitable sensors. According to this knowledge, we decided to describe the development and performance characteristics of the sol-gel glasses with a nanoporous structure as novel naked eye sensor for fast detection of vanadium (V) based on physical entrapment of 4-(2-pyridylazo) resorcinol inside pores of the silica matrix obtained by sol–gel technology. To design a highly sensitive and selective thin film without dopant leaching, several sols were made with different water: alkoxide ratios and pHs. In summary, this study revealed that the characteristics of porous matrix as well as its average pore size could play significant roles in almost all critical parameters affecting the sensor performance, including sensitivity, selectivity, and response time. The FE-SEM technique equipped with EDAX was also employed to evaluate the surface morphology, porosity growth, and elemental identification of the thin films. The calibration plot was obtained within 0.004–3.000 μg mL−1 of vanadium (V) with a detection limit value of 0.0014 μg mL−1.