Valorization of BaCO3 with 8-HQS to produce the optical chemo-probe for highly selective sensing of Cd2+ in aqueous media

Abstract

Valorization of chemicals is considered a method to prevent loss of valuable substances. Barium carbonate, as an initial precursor in chemical industries, is a suitable candidate for valorization to prevent the accumulation of waste BaCO₃ and the loss of these valuable resources. In this study, BaCO₃ was valorized with 8-hydroxyquinoline-5-sulfonate (8-HQS) to produce the optical chemo-probe for highly selective sensing of Cd²⁺ in aqueous media. The emission intensity of BaCO₃-8-HQS was enhanced in the presence of Cd²⁺ at 520 nm (λ_ex = 392 nm). The electrochemical experimental investigation, including cyclic voltammetry and Mott–Schottky techniques, revealed the ICT-enhancing mechanism of Cd²⁺ and showed Cd²⁺ interacts with the sulfonate head of BaCO₃-8-HQS. Furthermore, the as-prepared BaCO₃-8-HQS exhibited a good affinity and selectivity for sensing Cd²⁺, with a limit of detection of 2.2 × 10⁻⁷ M.