Abstract
A pH evaluation is required in numerous fields of life such as environmental monitoring, agriculture, and food science research. The chemical properties (acidity and basicity) of aqueous solutions can be determined by their pH values. Therefore, zincite-supported silica-anatase nanocomposite (ZSAC) is synthesized by the sol-gel method. Owing to the broad pH range 1–12 and fast response pH sensing characteristics, phenolphthalein is immobilized in ZSAC. FESEM analysis exhibited that both nanocomposites exhibited porous and self-assembled structures. Thermally stable ZSAC demonstrates low Ra (surface roughness) 1 nm, refractive index (n) 1.48 at 633 nm, and surface area 282 m2/g which varied to Ra 4 nm, n around 1.5, and surface area 345 m2/g after php immobilization. Both nanocomposites show heterogeneous chemical bonding. PZSAC revealed high pka around 11, fast color response 0.68 s in pH 12, and non-leachable behavior. Experimental findings suggested that synthesized nanocomposite has the capability for opto-chemical sensing applications.
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•Phenolphthalein immobilized zincite-supported silica-Anatase nanocomposite (ZSAC) is synthesized by sol-gel method pH sensing characteristics.•Thermally stable ZSAC demonstrates low Ra (surface roughness) 1 nm, refractive index (n) 1.48 at 633 nm, and surface area 282 m2/g.•Thermally stable PZSAC demonstrates Ra 4 nm, n around 1.5, and surface area 345 m2/g and heterogeneous chemical bonding.•PZSAC revealed high pka around 11, fast color response 0.68 s in pH 12, and non-leachable behavior.•Experimental findings suggested that synthesized nanocomposite has the capability for opto-chemical sensing applications.