A hyperaccumulation pathway to hierarchically porous carbon nanosheets from halophyte biomass for wastewater remediation
| Autor: | Ramavatar Meena, Gopala Ram Bhadu, Ashesh Mahto, Ankit Singh, Nataraj Sanna Kotrappanavar, Kanakaraj Aruchamy, Ashok Maraddi |
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| Rok vydání: | 2021 |
| Předmět: |
Renewable Energy
Sustainability and the Environment Carbonization Biomass chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Industrial and Manufacturing Engineering 0104 chemical sciences chemistry.chemical_compound Adsorption chemistry Wastewater Chemical engineering Halophyte Lignin General Materials Science 0210 nano-technology Waste Management and Disposal Pyrolysis Carbon |
| Zdroj: | Sustainable Materials and Technologies. 29:e00292 |
| ISSN: | 2214-9937 |
| DOI: | 10.1016/j.susmat.2021.e00292 |
| Popis: | Sustainable and eco-friendly production is vital to meet the ever-increasing demand for porous carbon materials. We propose a single step process to obtain porous carbon nanosheets (CNS) by exploiting the hyperaccumulating pathway in extreme halophyte, Salicornia brachiata. The process was designed so as to achieve seamless hybridization with already existing technologies of salt production while reducing the overall carbon and chemical footprint. Further, CNS were tested as an efficient adsorbent for wastewater remediation. The raw material, dried Salicornia brachiata biomass consisted of roughly ~30 w/w% hyperaccumulated inorganic salts while the organic constituents (cellulose, lignin etc.) made up for the rest. Compartmentalized salt in the plant structure acted as a templating agent while water washing after pyrolysis resulted in exfoliation and pore formation due to its dissolution. Morphology and texture analysis of the carbon material obtained from water washed biomass (salts removed) exemplified the structure and pore directing effect of intrinsic salt. The unwashed pyrolyzed sample (S7--UW) exhibited nominal BET area of ~90 m2/g while the value increased to ~700 m2/g for exfoliated CNS obtained after water washing (S7--W). Intrinsic salts not only act as a template, but also catalyses the carbonization process, increases carbon retention during pyrolysis and inhibits restacking of exfoliated graphitized carbon sheets after pyrolysis. S7--W displayed high removal capacity for Pb2+ (55 mg/g), Hg2+(~100 mg/g), Cd2+(~250–300 mg/g), maintaining its efficiency under seawater and simulated wastewater conditions. |
| Databáze: | OpenAIRE |
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