Thermally and optically functionalized titania nanoparticles for pH sensing

Abstract

Owing to the sensing applications, titania nanoparticles (TNPs) are synthesized by sol-gel route at low temperature (80 °C). For pH sensing response, four different pH dyes (phenol red, bromophenol blue, cresol red, and phenolphthalein) mixture is immobilized within TNPs. Thermal and structural behaviour of synthesized TNPs is observed by Thermo-gravimetric analysis (TGA), Fourier transmission infrared spectroscopy (FTIR), and Field emission scanning electron microscopy (FESEM). Thermally stable co-dyes immobilized TNPs confirms void-free surface morphology with heterogeneous chemical bonding. Furthermore, prepared sensing device has linear response with determination coefficient (R2) ∼ 0.97 and sensitivity is calculated as ∼154 I/pH at 431 nm. The response is optimized at pH 11.