Rapid and efficient adsorption of methylene blue dye from aqueous solution by hierarchically porous, activated starbons®: Mechanism and porosity dependence

Han Li, Vitaliy L. Budarin, James H. Clark, Michael North*, Xiao Wu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Hierarchically porous activated Starbons® derived from starch are found to make excellent adsorbents for methylene blue, even in the presence of other dyes and inorganic salts, highlighting their potential to be used in water purification. The optimal material (S950C90) has a methylene blue adsorption capacity (891 mg g-1) almost nine times higher than that of unactivated S800 and four times higher than that of commercial activated carbon at 298 K. The adsorption of methylene blue onto optimal materials (S950C90 and S800K4) reaches equilibrium within 5 min. Adsorption data for all the adsorbents show a good fit to the Freundlich isotherm which allows the Gibbs free energies of adsorption to be calculated. The adsorption capacities increase as the pH of the methylene blue solution increases, allowing the dye to be desorbed by treatment with acidic ethanol and the Starbon® materials reused. Porosimetry and SEM-EDX imaging indicate that methylene blue adsorbs throughout the surface and completely fills all the micropores in the Starbon® adsorbent. The methylene blue adsorption capacities show excellent correlations with both the BET surface areas and the micropore volumes of the materials.

Original languageEnglish
Article number129174
Number of pages16
JournalJournal of hazardous materials
Early online date9 Jun 2022
Publication statusPublished - 15 Aug 2022

Bibliographical note

Funding Information:
The authors thank the Chinese Scholarship Council for a scholarship (to HL).

Publisher Copyright:
© 2022 The Authors


  • Adsorption
  • Biomass
  • PH-swing
  • Starch-derived porous carbon
  • Water purification

Cite this