Photo-modulated regeneration of hypercrosslinked polymer adsorbents for water treatment

Aotian Liu, Xiuming Wei, Shiliang Lin, Liang Ding, Yi (Harvey) Huang, Xianfeng Fan, Pei Li, Cher Hon Lau*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Hypercrosslinked polymers (HCPs) are highly effective adsorbents for removing dyes from water. However, the regeneration of such adsorbents is typically achieved with energy-intensive thermal methods or with solvents that generate chemical waste. Here in this proof of concept study, we used HCPs loaded with azobenzene molecules (HCPs@Azo) that were developed in our previous work, and four types of dyes – Methyl Orange (MO), Methylene Blue (MB), Rhodamine B (RB), Uniblue A (UA), at concentrations ranging from 10 to 500 mg L−1, to demonstrate the feasibility of photo-modulated regeneration of HCP-based adsorbents. Azobenzene in HCP pores reduced dye adsorption by 4–31 %, but upon photo-isomerisation from trans to cis states, led to the desorption of 1.7–20 % dyes that were previously adsorbed. These desorption capacities were 71–209 % higher than using water for regeneration. Compared to the traditional method using organic solvents such as methanol to regenerate HCP-based adsorbents, our approach of photo-modulated regeneration led to the desorption of 50 % more MO and MB dyes. HCPs@Azo also demonstrated good reusability, showing comparable photo-modulated adsorption and desorption capacities after four cycles of UV–visible light irradiation. Results from this work can potentially pave the way for solvent-less regeneration of adsorbents, creating a waste-less adsorbent regeneration process.

Original languageEnglish
Article number125142
JournalSeparation and Purification Technology
Early online date22 Sept 2023
Publication statusPublished - 15 Jan 2024

Keywords / Materials (for Non-textual outputs)

  • Desorption
  • Dyes
  • Hypercross-linked polymers
  • Isotherm model
  • Kinetics
  • Photosensitive


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