Research hotspot analysis of nano zero-valent iron for water pollution treatment based on bibliometrics

WANG Sheng; HUANG Qing; LIU Zhaoli; LIU Airong

doi:10.7524/j.issn.0254-6108.2023021602

2023 Volume 42 Issue 11

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WANG Sheng, HUANG Qing, LIU Zhaoli, LIU Airong. Research hotspot analysis of nano zero-valent iron for water pollution treatment based on bibliometrics[J]. Environmental Chemistry, 2023, 42(11): 3729-3744. doi: 10.7524/j.issn.0254-6108.2023021602

Citation:

WANG Sheng, HUANG Qing, LIU Zhaoli, LIU Airong. Research hotspot analysis of nano zero-valent iron for water pollution treatment based on bibliometrics[J]. Environmental Chemistry, 2023, 42(11): 3729-3744. doi: 10.7524/j.issn.0254-6108.2023021602

Research hotspot analysis of nano zero-valent iron for water pollution treatment based on bibliometrics

1.
College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
2.
State Key Laboratory of Pollution Control and Resource Reuse, Shanghai, 200092, China

Corresponding author: LIU Airong, liuairong@tongji.edu.cn
Received Date: 16/02/2023
Accepted Date: 30/03/2023
Available Online: 27/11/2023

Fund Project: the National Science Foundation of China (42073082, 41673096), the National Key Research and Development Program of China (2019YFC1805300), and the Foundation of State Key Laboratory of Pollution Control and Resource Reuse (PCRRC20021).

Abstract

In recent decades, with the continuous development of industrial production, water pollution incidents have occurred frequently. Nanoscale zero-valent iron (nZVI) has received much attention as one of the hot materials for water pollution control. Based on the CiteSpace 6.1.R6 visualization software, this review covers Web of science core collection database for 25 years (1997—2022) for nZVI in water remediation. The results show that: (1) In the past 25 years, the development of nZVI in water pollution treatment has gone through three periods: the initial exploration period, the slow development period and the rapid growth period, with the number of publications accounting for 0.4%, 14.5% and 85.1% of the total number of publications, respectively; (2) The connection and cooperation among countries and institutions are closer, while the cooperation among authors is looser; (3) The research hotspots of the three periods are different, and the research topics are constantly broadened. The potential research hotspots in the future are the exploration of green and low cost synthesis methods of nZVI, the study of atomic scale mechanism of nZVI to remove pollutants, and the joint treatment of pollutants in complex media with microbial technology.
- bibliometrics,
- nanoscale zero-valent iron,
- CiteSpace,
- water pollution.

References

[1]	RAJESHKUMAR S, LIU Y, ZHANG X Y, et al. Studies on seasonal pollution of heavy metals in water, sediment, fish and oyster from the Meiliang Bay of Taihu Lake in China [J]. Chemosphere, 2018, 191: 626-638. doi: 10.1016/j.chemosphere.2017.10.078 CrossRef Google Scholar Pub Med
[2]	赵玉丽, 李杏放. 饮用水消毒副产物: 化学特征与毒性 [J]. 环境化学, 2011, 30(1): 20-33. ZHAO Y L, LI X. Drinking water disinfection byproducts: Chemical characterization and toxicity [J]. Environmental Chemistry, 2011, 30(1): 20-33(in Chinese). Google Scholar Pub Med
[3]	LIU X H, LU S Y, GUO W, et al. Antibiotics in the aquatic environments: A review of lakes, China [J]. Science of the Total Environment, 2018, 627: 1195-1208. doi: 10.1016/j.scitotenv.2018.01.271 CrossRef Google Scholar Pub Med
[4]	PHOON B L, ONG C C, MOHAMED SAHEED M S, et al. Conventional and emerging technologies for removal of antibiotics from wastewater [J]. Journal of Hazardous Materials, 2020, 400: 122961. doi: 10.1016/j.jhazmat.2020.122961 CrossRef Google Scholar Pub Med
[5]	CHEN G Y, YU Y, LIANG L, et al. Remediation of antibiotic wastewater by coupled photocatalytic and persulfate oxidation system: A critical review [J]. Journal of Hazardous Materials, 2021, 408: 124461. doi: 10.1016/j.jhazmat.2020.124461 CrossRef Google Scholar Pub Med
[6]	ZAMORA-LEDEZMA C, NEGRETE-BOLAGAY D, FIGUEROA F, et al. Heavy metal water pollution: A fresh look about hazards, novel and conventional remediation methods [J]. Environmental Technology & Innovation, 2021, 22(1957): 101504. Google Scholar Pub Med
[7]	高宝玉. 水和废水处理用复合高分子絮凝剂的研究进展 [J]. 环境化学, 2011, 30(1): 337-345. GAO B Y. Progress in the research of composite polymeric flocculants for water and wastewater treatment [J]. Environmental Chemistry, 2011, 30(1): 337-345(in Chinese). Google Scholar Pub Med
[8]	HUBE S, ESKAFI M, HRAFNKELSDÓTTIR K F, et al. Direct membrane filtration for wastewater treatment and resource recovery: A review [J]. The Science of the Total Environment, 2020, 710: 136375. doi: 10.1016/j.scitotenv.2019.136375 CrossRef Google Scholar Pub Med
[9]	OBOTEY EZUGBE E, RATHILAL S. Membrane technologies in wastewater treatment: A review [J]. Membranes, 2020, 10(5): 89. doi: 10.3390/membranes10050089 CrossRef Google Scholar Pub Med
[10]	MUTHUSARAVANAN S, SIVARAJASEKAR N, VIVEK J S, et al. Phytoremediation of heavy metals: Mechanisms, methods and enhancements [J]. Environmental Chemistry Letters, 2018, 16(4): 1339-1359. doi: 10.1007/s10311-018-0762-3 CrossRef Google Scholar Pub Med
[11]	WEI Z H, van LE Q, PENG W X, et al. A review on phytoremediation of contaminants in air, water and soil [J]. Journal of Hazardous Materials, 2021, 403: 123658. doi: 10.1016/j.jhazmat.2020.123658 CrossRef Google Scholar Pub Med
[12]	AL-MAMUN M R, KADER S, ISLAM M S, et al. Photocatalytic activity improvement and application of UV-TiO₂ photocatalysis in textile wastewater treatment: A review [J]. Journal of Environmental Chemical Engineering, 2019, 7(5): 103248. doi: 10.1016/j.jece.2019.103248 CrossRef Google Scholar Pub Med
[13]	任学昌, 马学琴, 任晓亮, 等. TiO₂/PANI/Fe₃O₄的低温水热法制备及其光催化活性与磁回收性能 [J]. 环境化学, 2013, 32(11): 2149-2155. doi: 10.7524/j.issn.0254-6108.2013.11.019 REN X C, MA X Q, REN X L, et al. Preparation of TiO₂/PANI/Fe₃O₄ by low temperature hydrothermal method and its photocatalytic activity and magnetic recovery characteristic [J]. Environmental Chemistry, 2013, 32(11): 2149-2155(in Chinese). doi: 10.7524/j.issn.0254-6108.2013.11.019 CrossRef Google Scholar Pub Med
[14]	黄潇月, 王伟, 凌岚, 等. 纳米零价铁与重金属的反应: “核-壳”结构在重金属去除中的作用 [J]. 化学学报, 2017, 75(6): 529-537. doi: 10.6023/A17020051 HUANG X Y, WANG W, LING L, et al. Heavy metal-nZVI reactions: The core-shell structure and applications for heavy metal treatment [J]. Acta Chimica Sinica, 2017, 75(6): 529-537(in Chinese). doi: 10.6023/A17020051 CrossRef Google Scholar Pub Med
[15]	LIU A R, LIU J, HAN J H, et al. Evolution of nanoscale zero-valent iron (nZVI) in water: Microscopic and spectroscopic evidence on the formation of nano- and micro-structured iron oxides [J]. Journal of Hazardous Materials, 2017, 322: 129-135. doi: 10.1016/j.jhazmat.2015.12.070 CrossRef Google Scholar Pub Med
[16]	刘静, 刘爱荣, 张伟贤. 纳米零价铁及其在环境介质中氧化后性质演变研究进展 [J]. 环境化学, 2014, 33(4): 576-583. doi: 10.7524/j.issn.0254-6108.2014.04.009 LIU J, LIU A R, ZHANG W X. Review on transformation of oxidized nanoscale zero valent iron in environment media [J]. Environmental Chemistry, 2014, 33(4): 576-583(in Chinese). doi: 10.7524/j.issn.0254-6108.2014.04.009 CrossRef Google Scholar Pub Med
[17]	刘爱荣, 李季, 王伟, 等. 纳米零价铁处理含重金属工业废水研究进展 [J]. 环境化学, 2022, 41(4): 1278-1291. doi: 10.7524/j.issn.0254-6108.2021082203 LIU A R, LI J, WANG W, et al. Advance of heavy metal-loading industrial wastewater treatment with nanoscale zero-valent iron [J]. Environmental Chemistry, 2022, 41(4): 1278-1291(in Chinese). doi: 10.7524/j.issn.0254-6108.2021082203 CrossRef Google Scholar Pub Med
[18]	YAO Y H, HUANG S M, ZHOU W, et al. Highly dispersed core-shell iron nanoparticles decorating onto graphene nanosheets for superior Zn(Ⅱ) wastewater treatment [J]. Environmental Science and Pollution Research, 2019, 26(1): 806-815. doi: 10.1007/s11356-018-3631-5 CrossRef Google Scholar Pub Med
[19]	LI Z T, WANG L, MENG J, et al. Zeolite-supported nanoscale zero-valent iron: New findings on simultaneous adsorption of Cd(Ⅱ), Pb(Ⅱ), and As(Ⅲ) in aqueous solution and soil [J]. Journal of Hazardous Materials, 2018, 344: 1-11. doi: 10.1016/j.jhazmat.2017.09.036 CrossRef Google Scholar Pub Med
[20]	JIANG Q, ZHANG Y, JIANG S M, et al. Graphene-like carbon sheet-supported nZVI for efficient atrazine oxidation degradation by persulfate activation [J]. Chemical Engineering Journal, 2021, 403: 126309. doi: 10.1016/j.cej.2020.126309 CrossRef Google Scholar Pub Med
[21]	ZHAO X, LIU W, CAI Z Q, et al. An overview of preparation and applications of stabilized zero-valent iron nanoparticles for soil and groundwater remediation [J]. Water Research, 2016, 100: 245-266. doi: 10.1016/j.watres.2016.05.019 CrossRef Google Scholar Pub Med
[22]	LU H J, WANG J K, FERGUSON S, et al. Mechanism, synthesis and modification of nano zerovalent iron in water treatment [J]. Nanoscale, 2016, 8(19): 9962-9975. doi: 10.1039/C6NR00740F CrossRef Google Scholar Pub Med
[23]	MUKHERJEE R, KUMAR R, SINHA A, et al. A review on synthesis, characterization, and applications of nano zero valent iron (nZVI) for environmental remediation [J]. Critical Reviews in Environmental Science and Technology, 2016, 46(5): 443-466. doi: 10.1080/10643389.2015.1103832 CrossRef Google Scholar Pub Med
[24]	WANG P, FU F G, LIU T Y. A review of the new multifunctional nano zero-valent iron composites for wastewater treatment: Emergence, preparation, optimization and mechanism [J]. Chemosphere, 2021, 285: 131435. doi: 10.1016/j.chemosphere.2021.131435 CrossRef Google Scholar Pub Med
[25]	LIU A R, FU J H, LIU J, et al. Copper nanostructure genesis via galvanic replacement and kirkendall growth from nanoscale zero-valent iron [J]. ACS ES& T Water, 2022, 2(8): 1353-1359. Google Scholar Pub Med
[26]	TESH S J, SCOTT T B. Nano-composites for water remediation: A review [J]. Advanced Materials, 2014, 26(35): 6056-6068. doi: 10.1002/adma.201401376 CrossRef Google Scholar Pub Med
[27]	HE F, LI Z J, SHI S S, et al. Dechlorination of excess trichloroethene by bimetallic and sulfidated nanoscale zero-valent iron [J]. Environmental Science & Technology, 2018, 52(15): 8627-8637. Google Scholar Pub Med
[28]	LIU X, CAO Z, YUAN Z L, et al. Insight into the kinetics and mechanism of removal of aqueous chlorinated nitroaromatic antibiotic chloramphenicol by nanoscale zero-valent iron [J]. Chemical Engineering Journal, 2018, 334: 508-518. doi: 10.1016/j.cej.2017.10.060 CrossRef Google Scholar Pub Med
[29]	LIU J, LIU A R, LI J, et al. Probing the performance and mechanisms of Congo red wastewater decolorization with nanoscale zero-valent iron in the continuing flow reactor [J]. Journal of Cleaner Production, 2022, 346: 131201. doi: 10.1016/j.jclepro.2022.131201 CrossRef Google Scholar Pub Med
[30]	KAO L C, HA Y, CHANG W J, et al. Trace key mechanistic features of the arsenite sequestration reaction with nanoscale zerovalent iron [J]. Journal of the American Chemical Society, 2021, 143(40): 16538-16548. doi: 10.1021/jacs.1c06159 CrossRef Google Scholar Pub Med
[31]	HAUSMANN J N, BELTRÁN-SUITO R, MEBS S, et al. Evolving highly active oxidic iron(III) phase from corrosion of intermetallic iron silicide to master efficient electrocatalytic water oxidation and selective oxygenation of 5-hydroxymethylfurfural [J]. Advanced Materials, 2021, 33(27): 2008823. doi: 10.1002/adma.202008823 CrossRef Google Scholar Pub Med
[32]	张礼知, 张伟贤. 铁环境化学: 环境和地球化学的研究热点 [J]. 化学学报, 2017, 75(6): 519-520. ZHANG, L Z, ZHANG, W X. Environmental chemistry of iron-a frontier in environmental chemistry and geochemistry [J]. Acta Chimica Sinica, 2017, 75(6): 519-520(in Chinese). Google Scholar Pub Med
[33]	CHENG Y J, DONG H R, LU Y, et al. Toxicity of sulfide-modified nanoscale zero-valent iron to Escherichia coli in aqueous solutions [J]. Chemosphere, 2019, 220: 523-530. doi: 10.1016/j.chemosphere.2018.12.159 CrossRef Google Scholar Pub Med
[34]	权衡, 牛琳, 时迪, 等. 负载纳米零价铁的铁碳材料制备及其降解抗生素性能研究 [J]. 环境科学研究, 2022, 35(12): 2732-2747. doi: 10.13198/j.issn.1001-6929.2022.07.17 QUAN H, NIU L, SHI D, et al. Preparation of iron-carbon materials loaded with nano zero-valent iron and their performance of degrading antibiotics [J]. Research of Environmental Sciences, 2022, 35(12): 2732-2747(in Chinese). doi: 10.13198/j.issn.1001-6929.2022.07.17 CrossRef Google Scholar Pub Med
[35]	YANG S M, LIU A R, LIU J, et al. Advance of sulfidated nanoscale zero-valent iron: Synthesis, properties and environmental application [J]. Acta Chimica Sinica, 2022, 80(11): 1536. doi: 10.6023/A22080345 CrossRef Google Scholar Pub Med
[36]	YAN J C, HAN L, GAO W G, et al. Biochar supported nanoscale zerovalent iron composite used as persulfate activator for removing trichloroethylene [J]. Bioresource Technology, 2015, 175: 269-274. doi: 10.1016/j.biortech.2014.10.103 CrossRef Google Scholar Pub Med
[37]	LIU A R, WANG W, LIU J, et al. Nanoencapsulation of arsenate with nanoscale zero-valent iron (nZVI): A 3D perspective [J]. Science Bulletin, 2018, 63(24): 1641-1648. doi: 10.1016/j.scib.2018.12.002 CrossRef Google Scholar Pub Med
[38]	ZHOU Y Y, TANG L, YANG G D, et al. Phosphorus-doped ordered mesoporous carbons embedded with Pd/Fe bimetal nanoparticles for the dechlorination of 2, 4-dichlorophenol [J]. Catalysis Science & Technology, 2016, 6(6): 1930-1939. Google Scholar Pub Med
[39]	HUANG Q, GU T H, LIU A R, et al. Probing pollutant reactions at the iron surface: A case study on selenite reactions with nanoscale zero-valent iron [J]. Environmental Science:Nano, 2021, 8(9): 2650-2659. doi: 10.1039/D1EN00458A CrossRef Google Scholar Pub Med
[40]	WANG C B, ZHANG W X. Synthesizing nanoscale iron particles for rapid and complete dechlorination of TCE and PCBs [J]. Environmental Science & Technology, 1997, 31: 2154-2156. Google Scholar Pub Med
[41]	CHANG J, WOO H, KO M S, et al. Targeted removal of trichlorophenol in water by oleic acid-coated nanoscale palladium/zero-valent iron alginate beads [J]. Journal of Hazardous Materials, 2015, 293: 30-36. doi: 10.1016/j.jhazmat.2015.03.021 CrossRef Google Scholar Pub Med
[42]	CHEN C M. CiteSpace Ⅱ: Detecting and visualizing emerging trends and transient patterns in scientific literature [J]. Journal of the American Society for Information Science and Technology, 2006, 57(3): 359-377. doi: 10.1002/asi.20317 CrossRef Google Scholar Pub Med
[43]	陈悦, 陈超美, 刘则渊, 等. CiteSpace知识图谱的方法论功能 [J]. 科学学研究, 2015, 33(2): 242-253. doi: 10.16192/j.cnki.1003-2053.2015.02.009 CHEN Y, CHEN C M, LIU Z Y, et al. The methodology function of CiteSpace mapping knowledge domains [J]. Studies in Science of Science, 2015, 33(2): 242-253(in Chinese). doi: 10.16192/j.cnki.1003-2053.2015.02.009 CrossRef Google Scholar Pub Med
[44]	CHEN C M, HU Z G, LIU S B, et al. Emerging trends in regenerative medicine: A scientometric analysis in CiteSpace [J]. Expert Opinion on Biological Therapy, 2012, 12(5): 593-608. doi: 10.1517/14712598.2012.674507 CrossRef Google Scholar Pub Med
[45]	ELLIOTT D W, ZHANG W X. Field assessment of nanoscale bimetallic particles for groundwater treatment [J]. Environmental Science & Technology, 2001, 35(24): 4922-4926. Google Scholar Pub Med
[46]	LI X Q, ZHANG W X. Iron nanoparticles: The core-shell structure and unique properties for Ni(Ⅱ) sequestration [J]. Langmuir:the ACS Journal of Surfaces and Colloids, 2006, 22(10): 4638-4642. doi: 10.1021/la060057k CrossRef Google Scholar Pub Med
[47]	BOPARAI H K, JOSEPH M, O’CARROLL D M. Kinetics and thermodynamics of cadmium ion removal by adsorption onto nano zerovalent iron particles [J]. Journal of Hazardous Materials, 2011, 186(1): 458-465. doi: 10.1016/j.jhazmat.2010.11.029 CrossRef Google Scholar Pub Med
[48]	LING L, HUANG X Y, ZHANG W X. Enrichment of precious metals from wastewater with core–shell nanoparticles of iron [J]. Advanced Materials, 2018, 30(17): 1705703. doi: 10.1002/adma.201705703 CrossRef Google Scholar Pub Med
[49]	LIU Y Z, WU T, WHITE J C, et al. A new strategy using nanoscale zero-valent iron to simultaneously promote remediation and safe crop production in contaminated soil [J]. Nature Nanotechnology, 2021, 16(2): 197-205. doi: 10.1038/s41565-020-00803-1 CrossRef Google Scholar Pub Med
[50]	WEI K, LI H, GU H Y, et al. Strained zero-valent iron for highly efficient heavy metal removal [J]. Advanced Functional Materials, 2022, 32(26): 2200498. doi: 10.1002/adfm.202200498 CrossRef Google Scholar Pub Med
[51]	DONG H R, DENG J M, XIE Y K, et al. Stabilization of nanoscale zero-valent iron (nZVI) with modified biochar for Cr(Ⅵ) removal from aqueous solution [J]. Journal of Hazardous Materials, 2017, 332: 79-86. doi: 10.1016/j.jhazmat.2017.03.002 CrossRef Google Scholar Pub Med
[52]	NGUYEN N H A, ŠPÁNEK R, KASALICKÃ V, et al. Different effects of nano-scale and micro-scale zero-valent iron particles on planktonic microorganisms from natural reservoir water [J]. Environmental Science:Nano, 2018, 5(5): 1117-1129. doi: 10.1039/C7EN01120B CrossRef Google Scholar Pub Med
[53]	NASIRI J, MOTAMEDI E, NAGHAVI M R, et al. Removal of crystal violet from water using β-cyclodextrin functionalized biogenic zero-valent iron nanoadsorbents synthesized via aqueous root extracts of Ferula persica [J]. Journal of Hazardous Materials, 2019, 367: 325-338. doi: 10.1016/j.jhazmat.2018.12.079 CrossRef Google Scholar Pub Med
[54]	KECIĆ V, KERKEZ Đ, PRICA M, et al. Optimization of azo printing dye removal with oak leaves-nZVI/H₂O₂ system using statistically designed experiment [J]. Journal of Cleaner Production, 2018, 202: 65-80. doi: 10.1016/j.jclepro.2018.08.117 CrossRef Google Scholar Pub Med
[55]	ZHANG N Q, CHEN J Y, FANG Z Q, et al. Ceria accelerated nanoscale zerovalent iron assisted heterogenous Fenton oxidation of tetracycline [J]. Chemical Engineering Journal, 2019, 369: 588-599. doi: 10.1016/j.cej.2019.03.112 CrossRef Google Scholar Pub Med
[56]	ZHANG D J, SHEN J Y, SHI H F, et al. Substantially enhanced anaerobic reduction of nitrobenzene by biochar stabilized sulfide-modified nanoscale zero-valent iron: Process and mechanisms [J]. Environment International, 2019, 131: 105020. doi: 10.1016/j.envint.2019.105020 CrossRef Google Scholar Pub Med
[57]	LING L, ZHANG W X. Enrichment and encapsulation of uranium with iron nanoparticle [J]. Journal of the American Chemical Society, 2015, 137(8): 2788-2791. doi: 10.1021/ja510488r CrossRef Google Scholar Pub Med
[58]	ZHANG W X. Nanoscale iron particles for environmental remediation: An overview [J]. Journal of Nanoparticle Research, 2003, 5(3): 323-332. Google Scholar Pub Med
[59]	KHIN M M, NAIR A S, BABU V J, et al. A review on nanomaterials for environmental remediation [J]. Energy & Environmental Science, 2012, 5(8): 8075-8109. Google Scholar Pub Med
[60]	ZOU Y D, WANG X X, KHAN A, et al. Environmental remediation and application of nanoscale zero-valent iron and its composites for the removal of heavy metal ions: A review [J]. Environmental Science & Technology, 2016, 50(14): 7290-7304. Google Scholar Pub Med
[61]	FAN D M, LAN Y, TRATNYEK P G, et al. Sulfidation of iron-based materials: A review of processes and implications for water treatment and remediation [J]. Environmental Science & Technology, 2017, 51(22): 13070-13085. Google Scholar Pub Med

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大规模工业化以来，全球水污染事件频发. 以我国为例，随着工业化发展，中国经历了急剧的环境恶化，造成了大范围的水体污染和生态破坏. 例如在我国太湖流域的部分地区，被发现水体、沉积物等重金属浓度过高，在鱼类和牡蛎各器官中发现铅、铜、镉和铬等重金属高度富集^[1]；地表水中常常有消毒副产物的检出^[2]；湖泊不同环境介质中抗生素普遍存在；在全球范围内，水和沉积物中抗生素的暴露水平相对较高^[3]. 目前传统的水体污染治理修复的方法主要有离子交换法、膜处理法、混凝-絮凝法、植物修复法、光催化法等^[4-7]，然而上述方法尚且存在一定的缺陷：膜处理法由于是通过压力驱动，往往需要很高的能量，使得处理成本大幅提高；且在膜直接过滤过程中，废水中的有机物、无机物、悬浮物等成分是潜在的污染物，会造成严重的膜污染，导致膜的使用寿命缩短^[8-9]；对于植物修复来说，虽然其成本低且绿色环保，但其也面临着严重耗时又耗空间的问题^[10-11]；光催化法同样面临着对于可见光的利用率低以及光催化剂用于大规模安装后的快速分离和回收困难的问题^[12-13].

而纳米零价铁材料能一定程度上弥补上述缺陷，其为一种直径大小介于1—100 nm之间的“零价”铁颗粒，其结构为“壳核结构”，即由铁氧化物壳层和零价铁内核构成^[14-15]，因为其具有良好的还原性能^[16-17]（其标准氧化还原电位约为−0.45 V）、吸附性能^[18-19]、优良的比表面积^[20-21]、产量丰富、易于获取和制备以及成本低廉等优势而在水处理中有良好的应用前景^[22-24]，能够广泛地去除水体中的污染物^[25]. 已有的研究表明，纳米零价铁可以有效地去除水体中的重金属、卤代物、硝基芳烃、染料化合物等污染物^[26-30]. 铁是地壳中含量最丰富的金属元素之一^[31]，制备纳米零价铁的原料来源广泛，同时，铁元素是地球化学循环的重要元素之一^[32]，因此纳米零价铁是绿色环境纳米材料，能最大限度地减少环境的二次污染^[33-34]. 1997年，在Environmental Science & Technology上报道了纳米零价铁用于地下水中卤代有机物还原脱卤以来，有关nZVI用于环境治理的研究蓬勃展开. 1997年距今的25年间，科技的进步推动了纳米零价铁这一领域的发展，研究者借助不断更新的技术对纳米零价铁的制备、改性、机理以及环境应用做出了深入的探究，图1为近25年来在纳米零价铁的研究历程^[35-41]，从纳米零价铁的制备（球磨法、化学还原法等）、纳米零价铁的改性（负载改性、硫化改性、双金属改性等）、通过高分辨透射电镜（transmission electronic microscope, TEM）、X-射线光电子能谱（X-ray photoelectron spectroscopy，XPS）、能量损失谱（energy electron lose spectra，EELS）、基于同步辐射光的X-射线吸收精细结构谱（X-ray adsorption fine structure，XAFS）等光谱学技术微观观察纳米零价铁表面性质、推测纳米零价铁去除污染物的机理，再到纳米零价铁的实际应用，纳米零价铁环境化学已经发展成为一个引人注目的学科.

文献计量学是一种分析某一科研领域发展的科学方法，知识图谱是文献计量学的一种表示方法，知识图谱是通过图的形式表达事物之间内在联系的知识库^[42]. CiteSpace是目前应用较为广泛的绘制知识图谱的可视化软件，通过CiteSpace可视化分析，可以体现出某一研究领域的研究现状、合作网络、研究热点等^[43-44]. 该文通过CiteSpace软件分析了25年来发表在Web of Science核心合集上的期刊文章，分析总结了25年来纳米零价铁在水体污染修复治理方面的研究进展以及未来可能的热点研究方向.

1. 材料与方法（Materials and methods）

1.1. 数据来源及检索式

笔者以Web of Science核心合集数据库为检索数据库，检索式为：TS=（nZVI OR nano zero valent iron OR nanoscale zero valent iron） AND TS=（water），文献类型为“Article”，检索时间范围为1997-01-01到2022-12-31，数据采集时间为2023年3月4日. 下载格式为“全记录与引用的参考文献”，文件格式为“纯文本”.

1.2. 研究方法

采用CiteSpace6.1.R6进行可视化分析，首先对收集到的2479篇文献进行去重操作，去除可能存在的资讯和无作者的文献，去重后结果仍为2479条文献. 分别统计国家、机构、作者对该领域的贡献，每个期刊的发文量的多少，并依据不同时期发文量的多少将整个研究时段分为3个时期，针对每个时期进行聚类和关键词突现分析，探讨各个时期的研究热点. 最后，对文献进行共被引分析，选取被引最高的文献以及每个阶段他引最高的综述文献进行深入分析，探寻对过去25年来纳米零价铁基材料用于水体污染修复治理领域有重要影响的文章. 可视化分析的参数设置为：（1）时间跨度为1997—2022，时间切片（time slicing）为1年；（2）选择的节点类型（node types）分别为作者（author）、机构（institution）、国家（country）、关键词（keyword）和被引文献（reference）；（3）连线强度（link strength）选择cosine算法；（4）算法标准（selection criteria）选择g index算法，k值设置为10或25，其他参数不变；（5）裁剪方式（pruning）选择Minimun Spanning Tree、Pruning sliced networks、Pruning the merged network；（6）聚类方法选择log-likelihood Ratio Test method（LLR）算法自动从施引文献的关键词中提取共现频次最高的关键词作为聚类标签.

3. 结论与展望（Conclusion and prospect）

3.1. 结论

（1）利用citeSpace对WoS核心合集上25年来（1997—2022年）关于纳米零价铁基材料用于水体污染修复治理领域的相关文献进行了文献计量学可视化分析，探索了该领域的发展脉络；主要从事该领域工作的国家、机构和作者之间的合作关系；对该领域发展有着重要贡献的经典文献；各个时期的研究热点以及未来可能的研究前沿等.

（2）发展脉络：25年来纳米零价铁基材料用于水体污染修复治理领域经历了初步探索期、缓慢发展期和迅速增长期3个时期，发文量分别占总发文量的0.4%、14.5%和85.1%，从初步探索期的10篇到缓慢发展期的359篇再到迅速增长期的2110篇这一文章增长的跨度也说明了对于该领域的研究越来越火热,同时介绍了每个发展阶段重要的研究成果，有利于读者掌握这一领域的发展脉络.

（3）合作网络：在纳米零价铁基材料用于水体污染修复治理领域国家间的合作十分密切，尤其是在中国、英格兰、捷克共和国等国家之间有着广泛的合作关系；Tongji University（同济大学）和Chinese Academic of Science（中国科学院）是在该领域合作较多的权威性机构，很多研究机构通过与这两个机构合作展开研究；而作者之间的合作相对较为松散，研究总体较为零碎，只有少数作者团体有稳定的合作对象. 在未来，各个国家、机构以及作者之间应当进一步加强相互之间的合作关系，加强彼此之间的联系，避免单打独斗的现象，以便更好的推动该领域的研究发展.

（4）研究热点与前沿：在纳米零价铁发展的这25年来，纳米零价铁基材料用于水体污染修复治理领域的研究热点也是不断地在发展变化的. 从初步发展期的关注重点集中在纳米零价铁的合成及其“还原作用”和“脱氯作用”等演变到缓慢发展期时受到广泛关注纳米零价铁对于实际水体的修复作用等，再演变到迅速增长期的纳米零价铁的“硫化”、“高级氧化”和“与生物处理的结合”等. 近5年的关键词突现分析结果表明，未来纳米零价铁的可能研究热点在于纳米零价铁的绿色合成方法的优化以及在复杂多元的体系中纳米零价铁与其他材料或者多种污染物之间的相互作用关系的探究.

（5）经典文献：通过被引文献分析找到了被引频次最高的文献，以及3个阶段中每个阶段他引频次最高的综述文献，这4篇文献主要详细综述了纳米零价铁的制备过程、改性方法、对多种类型的环境污染物的去除效果以及如何利用DFT和EXAFS等技术对纳米零价铁的机理进行探究等，对于想要较为系统地了解纳米零价铁基材料的研究者具有很大的帮助.

3.2. 展望

（1）纳米零价铁作为应用最广泛的环境纳米材料之一，为实现在地下水、土壤修复及废水处理领域的实际应用，其低成本宏量制备技术的开发，是未来的研究热点之一.

（2）纳米零价铁由于本身具有高活性，在与污染物的反应过程中，其本身的结构、性质也发生演变，从而对污染物的去除效能产生影响，研究纳米零价铁的动态结构性能演变与污染物去除效能的关系，评价环境归宿及其对于环境安全性的潜在影响，也是需要关注的问题之一.

（3）分析仪器的进步，使得原子尺度研究纳米零价铁与污染物之间分子水平的反应机理的成为可能，结合DFT理论计算，探索去除污染物反应的最本质的机理，也成为目前的热点之一.

（4）纳米零价铁技术具有良好的还原型和吸附性能，但是其本身仍然具有一定的局限性，与其他技术，如微生物技术联合进行复杂介质中污染物的去除，具有重要的研究前景.

Figure (5) Table (5) Reference (61)

Research hotspot analysis of nano zero-valent iron for water pollution treatment based on bibliometrics