Ultra-high surface area porous carbon from catechol rectification residue with excellent adsorption capacity for various organic pollutants

It is challenging to turn fine chemical industrial residue into porous carbons with ultrahigh surface area and excellent adsorption property for various organic pollutants. Herein, to address this issue, a novel NaNH₂ self-synergy strategy and other four traditional activation methods (KOH, H₃PO₄, CO₂ and air) were developed to synthesize different catechol rectification residue-based porous carbons. Then, structure characteristics, surface morphologyies and chemical properties of these carbons were analyzed to systematically investigate the effect of these methods on the structure-performance of carbons. Results showed that porous carbon (CC-N) prepared by NaNH₂ self-synergy strategy possessed ultrahigh specific surface area, up to 3954 m²/g, which was 1.5 ∼ 66 times higher than that of other carbons prepared by traditional activation methods and NaNH₂ activation without self-synergy strategy. Additionally, in-depth study revealed that part of NaNH₂ reacted with the water from residue carbon to form self-synergy effect during activation process. This effect brought the most comprehensive activation abilities. In terms of application, the adsorption capacity of CC-N for various popular organic pollutants was considerable. CC-N had the highest adsorption capacity (1205 mg/g) for tetracycline (TC) among most of the reported adsorbents. Adsorption mechanisms of TC onto CC-N were proved by hydrophobic interactions, π–π interaction, H-bond. In general, this article can be served as one new reference to improve the porosity and adsorption performance of porous carbon by novel adjustable NaNH₂ self-synergy strategy.