A review on the synthesis and applications of nanoporous carbons for the removal of complex chemical contaminants

Around 29% of the world population does not have ready access to safe drinking water. Water contamination is a compelling issue, which needs to be addressed on a priority basis using novel technologies. Heavy metals are the dominant inorganic contaminants found in the water, whereas, organic contaminants are composed of several classes and pose a more widespread problem. The occurrence of radionuclides, such as uranium and caesium in groundwater is also raising a serious issue but it is often understudied. Nanoporous carbons are a good choice for removing water contaminants owing to their excellent physico-chemical properties. Their surface properties, which are highly critical for adsorption, vary significantly with the nature of the precursors used for synthesis. Their textural and surface characteristics can be tuned by adjusting the chemical composition of these precursors or the synthesis conditions, including activation or modification. Such materials can also be supported in a porous matrix, designed into desired morphologies and hybridized with other composite materials for enhancing the application efficiency. The review describes how the low-cost nanoporous carbons are outstanding adsorbent for the water remediation and provide an outlook to tap the unlimited opportunities by researching their new properties.