Nanoporous carbon materials as a sustainable alternative for the remediation of toxic impurities and environmental contaminants: A review.

Due to rapidly deteriorating water resources, the world is looking forward to a sustainable alternative for the remediation of noxious pollutants such as heavy metals and organic and gaseous contaminants. To address this global issue of environmental pollution, nanoporous carbon materials (NPCMs) can be used as a one-stop solution. They are widely applied as adsorbents for many toxic impurities and environmental contaminants. The present review provides a detailed overview of the role of different synthesis factors on the porous characteristics of carbon materials, activating agents, reagent-precursor ratio and their potential application in the remediation. Findings revealed that synthetic parameters result in the formation of microporous NPCMs (S _BET : >4000 m ³ /g; V _Total (cm ³ /g) ≥ 2; V _Micro (cm ³ /g) ≥ 1), micromesoporous (S _BET : >2500 m ³ /g; V _Total (cm ³ /g) ≥ 1.5; V _Micro (cm ³ /g) ≥ 0.7) and mesoporous (S _BET : >2500 m ³ /g; V _Total (cm ³ /g) ≥ 1.5; V _Micro (cm ³ /g) ≥ 0.5) NPCMs. Moreover, it was observed that a narrow pore size distribution (0.5-2.0 nm) yields excellent results in the remediation of noxious contaminants. Further, chemical activating agents such as NaOH, KOH, ZnCl ₂ , and H ₃ PO ₄ were compared. It was observed that activating agents KОН, H ₃ PO ₄ , and ZnCl ₂ were generally used and played a significant role in the possible large-scale production and commercialization of NPCMs. Thus, it can be interpreted that with a well-planned strategy for the synthesis, NPCMs with a "tuned" porosity for a specific application, in particular, microporosity for the accumulation and adsorption of energetically important gases (CO ₂ , CH ₄ , H ₂ ), micro-mesoporosity and mesoporosity for high adsorption capacity for towards metal ions and a large number of dyes, respectively.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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