Sains Malaysiana 55(9)(2026): 1498-1511

http://doi.org/10.17576/jsm-2026-5509-08

 

Sulfur-Iron Modified Carboxylated Cellulose Nanofiber/Reduced Graphene Oxide Aerogel for Wastewater Remediation

(Aerogel Nanofiber Selulosa Terkarboksil/Grafena Oksida Terkurang Diubah Suai Sulfur-Besi untuk Pemulihan Air Sisa)

 

YUN XIA^1,#, XINTING LAI^2,#, JIANZHENG ZHEN^3,* & WENTAO WANG²

 

¹College of Fashion and Design, Jiaxing Vocational ＆ Technical College, Jiaxing 314036, China

²School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 30018, China

³College of Materials Science and Engineering, Linyi Institute of Technology, Linyi, China

 

Received: 30 April 2026/Accepted: 25 August 2026

 

*Corresponding author; email: zhenfangxu2018@163.com

 

^#These authors contributed equally to this work

ABSTRACT

Integrating adsorption with advanced oxidation processes (AOPs) is a promising but challenging strategy for wastewater remediation. Herein, a sulfur-iron modified carboxylated cellulose nanofiber/reduced graphene oxide (CCNF/rGO/Fe‑S) aerogel was fabricated using CCNF as a fibrous skeleton to function as a dual‑functional adsorbent and catalyst for synergistic pollutant adsorption and catalytic degradation. The CCNF/rGO/Fe‑S aerogel showed prominent selective adsorption toward cationic dyes including methylene blue (MB), rhodamine B (RhB) and crystal violet (CV), with adsorption capacities of 757.1, 911.0, and 1281.4 mg·g⁻¹, respectively, obviously higher than those of the iron modified carboxylated cellulose nanofiber/reduced graphene oxide (CCNF/rGO/Fe) aerogel. Its initial adsorption rates were over three times higher than those of the CCNF/rGO/Fe aerogel, and the composite maintained pollutant removal efficiency above 80% after five cycles, showing favorable reusability and structural stability. Theoretical analysis confirmed that π‑π stacking and electrostatic interactions driven by CCNF carboxyl groups dominate pollutant adsorption. Differing from traditional photocatalytic CCNF aerogels, the material efficiently activates PMS without light irradiation to generate singlet oxygen (¹O₂), sulfate radicals (SO₄^•−) and hydroxyl radicals (•OH), realizing deep degradation and mineralization of adsorbed organics. CCNF carboxyl groups synergize with Fe‑S sites to integrate adsorption and catalysis rather than merely acting as a skeleton. This study offers a feasible route to fabricate high‑efficiency fiber‑based composites for practical complex wastewater system.

Keywords: Adsorption; cellulose nanofiber aerogel; degradation; sulfidated zero-valent iron; wastewater remediation

 

ABSTRAK

Penggabungan proses penjerapan dengan proses pengoksidaan lanjutan merupakan strategi yang berpotensi namun mencabar bagi pemulihan air sisa. Dalam kajian ini, aerogel nanofiber selulosa terkarboksil/grafena oksida terkurang yang diubah suai sulfur-besi telah dihasilkan dengan menggunakan nanofiber selulosa terkarboksil sebagai rangka gentian. Bahan ini berperanan sebagai penjerap dan pemangkin dwifungsi untuk melaksanakan penjerapan bahan pencemar dan penguraian pemangkin secara sinergistik. Aerogel nanofiber selulosa terkarboksil/grafena oksida terkurang yang diubah suai sulfur-besi menunjukkan keupayaan penjerapan selektif yang luar biasa terhadap pewarna kation, termasuk metilena biru, rodamin B dan kristal violet. Kapasiti penjerapannya masing-masing ialah 751.2, 911.0 dan 1281.4 mg·g⁻¹, yang jelas lebih tinggi berbanding aerogel nanofiber selulosa terkarboksil/grafena oksida terkurang yang diubah suai besi tulen. Kadar penjerapan awal bahan ini adalah lebih tiga kali ganda berbanding aerogel nanofiber selulosa terkarboksil/grafena oksida terkurang yang diubah suai besi. Komposit ini mengekalkan kecekapan penyingkiran bahan pencemar melebihi 80% selepas lima kitaran ujian, membuktikan kebolehgunaan semula dan kestabilan strukturnya yang baik. Analisis teori mengesahkan bahawa tindanan π-π dan interaksi elektrostatik yang dicetuskan oleh kumpulan karboksil nanofiber selulosa terkarboksil menjadi faktor dominan dalam proses penjerapan bahan pencemar. Berbeza dengan aerogel nanofiber selulosa terkarboksil fotopemangkin konvensional, bahan ini mampu mengaktifkan peroksimonosulfat dengan cekap tanpa keperluan sinaran cahaya, lalu menjana oksigen singlet, radikal sulfat dan radikal hidroksil. Hal ini membolehkan penguraian mendalam dan mineralisasi sebatian organik yang telah terjerap. Kumpulan karboksil nanofiber selulosa terkarboksil bersinergi dengan tapak sulfur-besi untuk menyatukan fungsi penjerapan dan pemangkinan dan bukan sekadar bertindak sebagai rangka struktur sahaja. Kajian ini menyediakan pendekatan yang praktikal untuk menghasilkan komposit berasaskan gentian berkecekapan tinggi, yang sesuai digunakan dalam sistem rawatan air sisa kompleks sebenar.

Kata kunci: Aerogel selulosa nanofiber; besi sifar valen tersulfidasi; pemulihan air sisa; penguraian; penjerapan

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