{"title":"Modulating d-orbital electronic configuration of magnetic iron sulfide nanocrystals for maximized treatment efficiency of chromium-contaminated water","authors":"Yaqi Liu, Can Liu, Xiaofan Peng, Zongsheng Liang, Shengli Hou, Wei Chen, Tong Zhang","doi":"10.1016/j.watres.2025.123477","DOIUrl":null,"url":null,"abstract":"<div><div>Hexavalent chromium (Cr(VI)) is one of the most rigorously regulated contaminants frequently detected in surface and groundwater. Magnetic iron sulfides are naturally abundant, environmentally friendly materials ideal for the removal of Cr(VI) from contaminated water, but the high-spin states of Fe(III) ions limits their adsorption affinity. Herein, we develop a heteroatom-doping approach to boost the Cr(VI) removal efficacy of greigite. Compared to pristine greigite, cobalt doping significantly enhances the capability of greigite to adsorption Cr(VI) by decreasing electron occupancy in the <em>e<sub>g</sub></em> orbitals and reducing the spin state of Fe ions. With a combination of electrochemical characterizations and theoretical calculations, we confirm that cobalt doping significantly enhances its reduction capacity toward Cr(VI) by elevating the <em>d-</em>band center and increasing electron transfer rate. We corroborate the finding by showing that Cu-doping, which has the opposite effects on <em>d</em>-orbital electron configures, compromises the efficacy of greigite. Of note, the magnetic properties of greigite remain largely unaffected upon heteroatom doping, allowing easy separation and recovery of the materials from the aqueous solutions. This work provides valuable mechanistic insights for nanomaterial design in contaminant removal and may inform the development of nanotechnology for green remediation of contaminated sites.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"280 ","pages":"Article 123477"},"PeriodicalIF":11.4000,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0043135425003902","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
摘要
六价铬(Cr(VI))是地表水和地下水中经常检测到的受到最严格管制的污染物之一。磁性硫化铁是天然丰富的环保材料,是去除受污染水体中六价铬的理想材料,但是铁(III)离子的高自旋态限制了其吸附亲和力。在此,我们开发了一种杂原子掺杂方法来提高绿泥石去除六价铬的功效。与原始的绿泥石相比,钴掺杂通过降低eg轨道的电子占有率和铁离子的自旋态,显著增强了绿泥石吸附六价铬的能力。结合电化学特性分析和理论计算,我们证实掺钴可通过提高 d 带中心和增加电子转移率来显著增强对 Cr(VI) 的还原能力。我们还证实了这一发现,掺杂铜对 d-轨道电子构型的影响恰恰相反,会损害绿泥石的功效。值得注意的是,掺杂杂原子后,绿泥石的磁性能基本不受影响,因此很容易从水溶液中分离和回收材料。这项工作为污染物去除方面的纳米材料设计提供了宝贵的机理启示,并可为污染场地绿色修复纳米技术的开发提供参考。
Modulating d-orbital electronic configuration of magnetic iron sulfide nanocrystals for maximized treatment efficiency of chromium-contaminated water
Hexavalent chromium (Cr(VI)) is one of the most rigorously regulated contaminants frequently detected in surface and groundwater. Magnetic iron sulfides are naturally abundant, environmentally friendly materials ideal for the removal of Cr(VI) from contaminated water, but the high-spin states of Fe(III) ions limits their adsorption affinity. Herein, we develop a heteroatom-doping approach to boost the Cr(VI) removal efficacy of greigite. Compared to pristine greigite, cobalt doping significantly enhances the capability of greigite to adsorption Cr(VI) by decreasing electron occupancy in the eg orbitals and reducing the spin state of Fe ions. With a combination of electrochemical characterizations and theoretical calculations, we confirm that cobalt doping significantly enhances its reduction capacity toward Cr(VI) by elevating the d-band center and increasing electron transfer rate. We corroborate the finding by showing that Cu-doping, which has the opposite effects on d-orbital electron configures, compromises the efficacy of greigite. Of note, the magnetic properties of greigite remain largely unaffected upon heteroatom doping, allowing easy separation and recovery of the materials from the aqueous solutions. This work provides valuable mechanistic insights for nanomaterial design in contaminant removal and may inform the development of nanotechnology for green remediation of contaminated sites.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.