RESUMEN
MOFs with their accessible voids/channels have been explored immensely for sensing due to their exclusive host-guest chemistry. However, unavailability of pores/voids in interpenetrating non-porous MOFs limits their applications in sensing. We herein report for the first time, hitherto, a non-porous MOF with an interpenetrating ladder structure for iodide sensing. A Co-bpe MOF was synthesized by hydrothermal reaction between cobalt nitrate and 1,2-bis(4-pyridyl)ethylene (bpe) in methanol and tested against colorimetric sensing of halides. The supramolecular structure of the Co-bpe MOF was stabilized through strong hydrogen bonding. We propose a double nucleophilic substitution reaction mechanism for iodide detection, which is one of its own kind. While Co-bpe showed a significant color change from dark maroon to dark green in the presence of iodide, the rest of halides did not display any pronounced colorimetric effect. The limit of detection (LOD) of this material was found to be 2.7 × 10-7 M. This article focuses on the equal competency of non-porous MOF materials with the porous MOFs in sensing applications.
RESUMEN
The rate of environmental pollution augmenting at an alarming rate due to the continuous disposal of toxic dyes directly into the environment and water streams. The direct contact of dyes with water resources directly affects the living beings. The identification of superior methods for the treatment of water pollution caused due to effluent dyes needs higher consideration among researchers for the well-being of living flora and fauna. The available methods for controlling the decontamination of water through toxic dyes have various drawbacks. So, it is highly significant to develop such materials which can easily adsorb the dyes without causing any toxic effect on the environment and living beings. While keeping all the facts in mind, the current work highlights the comparative enhancement in adsorption capacity and selectivity of Brij-58-coated selenium nanoparticles (Brij-58@Se NPs) towards the removal of bromophenol blue (BB) dye from series of chosen dyes in aqueous media. The fabricated Se NPs were methodically characterized and the adsorption behaviour displayed fast adsorption efficiency (98% within 6 min) for BB dye out of series of chosen dyes. The optimization studies were carried out to verify the influence of working variables such as pH (2.0-12.0), response time (1-10 min), dosage amount (0.1-80 mg/l) and concentration of BB dye (1-70 ppm). The adsorption process found to be best fitted for Freundlich adsorption isotherm and pseudo first-order kinetic model. The interference studies of different cationic, anionic species including dyes or metal ions suggested the higher efficiency of Brij-58@Se NPs for adsorptive removal of BB dye from aqueous media. The efficacy of the adsorbent was further tested in six different water resources and displayed 95% adsorption efficiency for BB dye in different wastewater samples. Therefore, Brij-58@Se NP is expected as a potential adsorbent for the adsorption of organic dyes from wastewater samples.