Binder-free production of 3D N-doped porous carbon cubes for efficient Pb2+ removal through batch and fixed bed adsorption. (1st December 2017)

• Record Type: Journal Article
• Authors: Sawant, Sandesh Y.; Pawar, Radheshyam R.; Lee, Seung-Mok; Cho, Moo Hwan
• Is Part Of: Journal of cleaner production. Volume 168(2017)
• Page Start: 290
• Page End: 301
• Publication Date: 2017-12-01
• Subjects: 3D adsorbent -- Water treatment -- Pb2+ adsorption -- N-doped carbon -- Carbon cubes; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2017.08.229
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: N-doped carbon cubes (NCCs) with varying nitrogen contents and different densities were fabricated using a simple and binder-free method that involved the curing of resorcinol-formaldehyde (RF) gel with different RF contents in the framework of a melamine sponge. In addition to the robust structure and nitrogen doping, the porosity of the NCCs could be tailored easily within the mesopores and ultra-micropores with a unique combination of macro, meso, and micropores. The prepared NCCs exhibited excellent uptake capacity, ranging from 32.1 to 39.3 mg/g Pb 2+ ions, owing to their high surface area (up to 675 m 2 /g) and nitrogen doping (max. 4.9 wt. %). The Pb 2+ adsorption property of NCC-10 was also compared with that of widely used commercial 3D carbon adsorbents. The weight and surface area-normalized Pb 2+ adsorption capacity of NCC-10 was found to be 3.7 and 6.6 times higher, respectively than the commercial activated carbon granules. The continuous mode model data fitted with experimental fixed-bed results well, and showed 8.95 mg/g loading capacity, proving that NCC-10 is an effective 3D adsorbent. The prepared NCCs could be used as a practical adsorbent for the removal of Pb 2+ ions because of their high adsorption capacity, easy regeneration, and exceptional stability maintained after longer reuse. Graphical abstract: Highlights: Binder-free method for the synthesis of 3D N-doped carbon cubes (NCCs) is reported. NCCs possess high porosity with unique combination of macro, meso, and micropores. N-doping and porosity can be tailored by varying resorcinol-formaldehyde content. NCCs showed higher Pb 2+ adsorption capacity than commercial 3D carbon adsorbents. A long-term and continuous Pb 2+ removal can be achieved with fixed bed adsorption.