Hydrolytically stable luminescent Sn(II)-BTEC hybrid material: Selective sensing of chromate ions in aqueous medium

Abstract

Highly efficient detection and sequestration of heavily toxic Chromate (CrO42¯) anion from the aqueous medium remains a challenging issue for the protection of public health and the ecosystem. Herein, we report a new thermally and hydrolytically stable Sn(II)-based hybrid organic-inorganic porous composite, and investigated its potential as a luminescent probe for instant and selective detection of chromate (CrO42¯) ions from the aqueous medium. The presence of chromate ions (CrO42¯) caused significant quenching (∼95 %) of the luminescence intensity of Sn(II)-BTEC. The material displayed remarkable selectivity towards CrO42¯ions in the presence of interfering metal cations and anions. The detection limit for CrO42¯ ions is calculated as low as 1.92 μM, which is significant in terms of trace amount detection from the aqueous medium. Further, the application of Sn(II)-BTEC as a chromate sensing probe in real water samples viz. tap water and lake water were examined. The synthesized Sn(II)-BTEC chemosensor displayed excellent chromate sensing capability and effectively reduced the Cr(VI) concentration within the U.S Environmental Protection Agency permissible limit of 100 μg L−1 for drinking water. Our work highlights the utility of Sn(II)-BTEC as a novel material for efficient sorption and selective luminescent sensing of chromate ions in environmentally relevant conditions.