Hierarchically crosslinked g-C3N4/aminated lignin/alginate aerogels for sustainable oil-in-water emulsion separation

Qinfen Tian; Juan Lu; Yuhui He; Defa Peng; Ziqiang Ma; Yibin Wu; Chunhui Han; Xuexia Zhang; Zhanhui Yuan; Yuan Hu; Jiandong Zhuang

doi:10.1016/j.ijbiomac.2025.147226

Hierarchically crosslinked g-C₃N₄/aminated lignin/alginate aerogels for sustainable oil-in-water emulsion separation

Int J Biol Macromol. 2025 Sep;323(Pt 2):147226. doi: 10.1016/j.ijbiomac.2025.147226. Epub 2025 Sep 1.

Authors

Qinfen Tian¹, Juan Lu², Yuhui He², Defa Peng², Ziqiang Ma², Yibin Wu², Chunhui Han², Xuexia Zhang², Zhanhui Yuan³, Yuan Hu⁴, Jiandong Zhuang⁵

Affiliations

¹ National Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials, College of Materials Engineering, Fujian Agriculture and Forestry University, Fuzhou 350108, China; College of Media and Exhibition, Fujian Business University, Fuzhou 350500, China.
² National Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials, College of Materials Engineering, Fujian Agriculture and Forestry University, Fuzhou 350108, China.
³ National Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials, College of Materials Engineering, Fujian Agriculture and Forestry University, Fuzhou 350108, China. Electronic address: zhanhuiyuan@fafu.edu.cn.
⁴ College of Materials and Chemical Engineering, Minjiang University, Fuzhou 350108, China. Electronic address: yuanhu@mju.edu.cn.
⁵ National Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials, College of Materials Engineering, Fujian Agriculture and Forestry University, Fuzhou 350108, China. Electronic address: jdzhuang@gmail.com.

PMID: 40897270
DOI: 10.1016/j.ijbiomac.2025.147226

Abstract

Biomass-based materials face challenges in treating industrial oily wastewater, particularly stable oil-in-water emulsions, due to limitations like poor mechanical strength and fouling susceptibility. To address this, a robust g-C₃N₄/aminated lignin/sodium alginate (GNALS) aerogel was engineered via chemical/ionic dual crosslinking and freeze-drying. This design integrates exfoliated g-C₃N₄ nanosheets (providing roughness and photocatalysis) and amine-functionalized lignin (natural crust agent and antioxidant) into an alginate matrix, forming a multi-network structure with enhanced mechanical robustness (4250 times self-weight load capacity, 0.78 MPa wet tensile strength), superhydrophilicity (oil contact angles ≥159.3°), antioxidant activity (75.2 % DPPH scavenging), and photocatalytic functionality. The hierarchical micro/nano-roughness structure and superwettability surface enable efficient demulsification via droplet coalescence, and achieving 99.5 % separation efficiency for soybean oil-in-water emulsions with gravity-driven (485.48 L∙m^-2∙h^-1) and negative pressure-driven (1433.12 L∙m^-2∙h^-1) fluxes. The g-C₃N₄-driven photocatalytic self-cleaning degrades adsorbed pollutants, enables >98.5 % efficiency recovery after 10 cycles under xenon lamp irradiation. This work establishes a multi-component synergy strategy for biomass aerogels, advancing hierarchical engineering principles for sustainable wastewater remediation.

Keywords: Aminated lignin; Demulsification and separation; Exfoliated g-C(3)N(4) nanosheets; Multiple-crosslinked framework; Robust alginate-based aerogels; Superwettability.

MeSH terms

Alginates* / chemistry
Amination
Catalysis
Emulsions / chemistry
Gels / chemistry
Lignin* / chemistry
Oils* / chemistry
Water* / chemistry

Substances

Lignin
Alginates
Emulsions
Water
Gels
Oils