{"title":"Electronic structure modulation of schwertmannite by interfacial chemical bond for enhanced photo-Fenton catalytic activity","authors":"Xuqian Wang, Zhe Wang, Tianyu Wang, Anqi Wang, Jiepeng Wang, Yongkui Zhang, Yabo Wang","doi":"10.1016/j.jcat.2025.116426","DOIUrl":null,"url":null,"abstract":"<div><div>The rational design of Fe-based catalysts with optimized electronic structures remains critical for achieving efficient pollutant degradation in photo-Fenton systems. This study presents a facile biomineralization approach to structurally modulate biogenic schwertmannite (Sch, Fe<sub>8</sub>O<sub>8</sub>(OH)<sub>8-2x</sub>(SO<sub>4</sub>)<sub>x</sub>, 1 ≤ x ≤ 1.75) through xanthan gum (XG) addition. The abundant carboxyl group on XG provided well-dispersed nucleation sites, which modulated the growth of Sch crystal clusters and effectively transformed aggregated Sch particles into nanowhisker-embedded hybrid network (Sch-XG) with 9.6-fold increased specific surface area. Moreover, strong interfacial chemical-bonded of Fe-O-C bridge was proved to exist between surface iron species of Sch and carboxyl group of XG, which further changed the energy band and electronic structure of Sch. Eventually, such modification facilitated photogenerated electron transfer, Fe(III)/Fe(II) cycling and enhanced adsorption-activation of H<sub>2</sub>O<sub>2</sub> by Sch-XG hybrid, which demonstrated good photo-Fenton performance, achieving complete sulfamethoxazole (SMX) removal within 20 min (<em>k</em> = 0.179 min<sup>−1</sup>) through synergistic radical-nonradical pathways dominated by surface-bound •OH. Notably, the Sch-XG hybrid exhibited broad pH adaptability (3.0–9.0), low iron leaching (<0.37 mg L<sup>−1</sup>), and >99 % SMX degradation efficiency after fourth cycles. After degradation products identification and ROS attack sites analysis, three primary SMX transformation routes via hydroxylation, ring opening and S-N bond cleavage were proposed, while effective detoxification of SMX was achieved through toxicity prediction and bio-toxicity assessment. This work provided a feasible interfacial engineering strategy to enhance catalytic potential of natural iron minerals for sustainable water remediation.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116426"},"PeriodicalIF":6.5000,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Catalysis","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0021951725004920","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The rational design of Fe-based catalysts with optimized electronic structures remains critical for achieving efficient pollutant degradation in photo-Fenton systems. This study presents a facile biomineralization approach to structurally modulate biogenic schwertmannite (Sch, Fe8O8(OH)8-2x(SO4)x, 1 ≤ x ≤ 1.75) through xanthan gum (XG) addition. The abundant carboxyl group on XG provided well-dispersed nucleation sites, which modulated the growth of Sch crystal clusters and effectively transformed aggregated Sch particles into nanowhisker-embedded hybrid network (Sch-XG) with 9.6-fold increased specific surface area. Moreover, strong interfacial chemical-bonded of Fe-O-C bridge was proved to exist between surface iron species of Sch and carboxyl group of XG, which further changed the energy band and electronic structure of Sch. Eventually, such modification facilitated photogenerated electron transfer, Fe(III)/Fe(II) cycling and enhanced adsorption-activation of H2O2 by Sch-XG hybrid, which demonstrated good photo-Fenton performance, achieving complete sulfamethoxazole (SMX) removal within 20 min (k = 0.179 min−1) through synergistic radical-nonradical pathways dominated by surface-bound •OH. Notably, the Sch-XG hybrid exhibited broad pH adaptability (3.0–9.0), low iron leaching (<0.37 mg L−1), and >99 % SMX degradation efficiency after fourth cycles. After degradation products identification and ROS attack sites analysis, three primary SMX transformation routes via hydroxylation, ring opening and S-N bond cleavage were proposed, while effective detoxification of SMX was achieved through toxicity prediction and bio-toxicity assessment. This work provided a feasible interfacial engineering strategy to enhance catalytic potential of natural iron minerals for sustainable water remediation.
期刊介绍:
The Journal of Catalysis publishes scholarly articles on both heterogeneous and homogeneous catalysis, covering a wide range of chemical transformations. These include various types of catalysis, such as those mediated by photons, plasmons, and electrons. The focus of the studies is to understand the relationship between catalytic function and the underlying chemical properties of surfaces and metal complexes.
The articles in the journal offer innovative concepts and explore the synthesis and kinetics of inorganic solids and homogeneous complexes. Furthermore, they discuss spectroscopic techniques for characterizing catalysts, investigate the interaction of probes and reacting species with catalysts, and employ theoretical methods.
The research presented in the journal should have direct relevance to the field of catalytic processes, addressing either fundamental aspects or applications of catalysis.