# Tailoring Biomass‐Derived Organosolv Lignin Derivatives for High‐Capacity Adsorption of Rhodamine B

## TL;DR

Researchers modified lignin to create a sustainable material that efficiently removes Rhodamine B dye from water.

## Contribution

A one-step lignin-first approach was used to synthesize high-capacity adsorbents from biomass-derived lignin.

## Key findings

- Resorcinol-modified lignin achieved the highest RhB adsorption capacity of 101.2 mg g−1.
- Adsorption followed pseudo-second-order kinetics, indicating chemisorption as the dominant mechanism.
- Resorcinol-modified lignin retained 62% efficiency after five reuse cycles.

## Abstract

The valorization of biomass into renewable, high‐performance, adsorbent materials offers a sustainable alternative to conventional synthetic sorbents. In this study, we investigate the potential of lignin derivatives as efficient adsorbents for removing the cationic dye Rhodamine B (RhB) from aqueous solutions. Five organosolv lignin derivatives were synthesized via a one‐step process using phenol, catechol, resorcinol, pyrogallol, and hydroquinone as phenolic modifiers to introduce structural diversity. The influence of these modifications on the materials’ physicochemical properties and adsorption behavior was examined. Comprehensive characterization included 31P NMR, Brunauer–Emmet–Teller surface area analysis, size exclusion chromatography, thermogravimetric analysis, and dynamic light scattering. Among the derivatives, resorcinol‐modified lignin (ReL) showed the highest RhB adsorption capacity (101.2 mg g−1), attributed to its favorable textural properties—high surface area and pore volume—together with increased availability of functional groups, which collectively enhanced adsorption efficiency. Adsorption kinetics for all materials followed the pseudo‐second‐order model, indicating chemisorption as the dominant mechanism. Isotherm analyses revealed Langmuir‐type monolayer adsorption for ReL, pyrogallol‐modified, and hydroquinone‐modified lignins. Moreover, ReL demonstrated good recyclability, retaining 62% of its adsorption efficiency after five adsorption–desorption cycles. Collectively, these results highlight the promise of structurally engineered lignin‐based adsorbents as cost‐effective, efficient, and reusable materials for sustainable wastewater treatment.

Organosolv lignin derivatives modified with phenolic compounds were synthesized via a one‐step lignin‐first approach and evaluated as renewable adsorbents for removing Rhodamine B dye from water. Among them, resorcinol‐modified lignin showed the highest adsorption capacity (101 mg g−1), driven by high surface area, pore volume, and accessible hydroxyl groups enabling efficient and reusable RhB capture.© 2026 WILEY‐VCH GmbH