Advanced functional porous materials for sensing and sequestration of toxic pollutants

Abstract

Environmental pollution has become a genuine concern worldwide posing direct threat to all living systems. Amongst various types of environmental pollutions, air pollution and water pollution are the most important contributors in this respect and demands immediate mitigation. Air pollution is caused majorly due to the anthropogenic emission of greenhouse gases and volatile organic compounds. On the other hand, release of harmful organic and inorganic wastes from industries and nuclear power plants into natural water bodies serves as the source for major water contamination. Advanced porous materials includes metal-organic frameworks (MOFs), a distinct class of hybrid crystalline porous molecular solids built in combination of organic struts and inorganic metal nodes/clusters while porous organic materials (POMs) are built on covalent and non-covalent attachment of functional organic moieties. These solid-state materials can be strategically designed with desired chemical functionality through fine-tuning of the building blocks at molecular level enabling them for broad spectrum of potential applications in the fields of sorption, catalysis, sensing and pollutant capture. Our efforts particularly explore applications in the domain of toxic pollutant sensing as well as their sequestration by task-specific functional porous materials. In brief, the first part of the work a stable functionalized MOF has being employed for the selective detection of a toxic volatile organic air pollutant styrene. Further, a post-synthetically modified MOF has been utilized for detection of bisulfite anion (a hydrolyzed oxo-anion of sulphur dioxide) in water. In the second part of the work, recognition as well as sequestration of iodine from both vapor phase and water has been demonstrated with functionalized porous organic materials. In addition, efficient removals of toxic and hazardous oxo-anions have been also realized with an ionic porous organic network by exploiting electrostatics driven anion exchange.