The widespread plastic pollution has raised significant concerns. The breakdown process of plastic debris during weathering not only generate microplastics and nanoplastics, but also release large quantities of harmful chemical additives such as phthalates and organophosphate esters (OPEs). Metal oxides, particularly those in the form of nanoparticles, play an essential role in mediating the environmental transformation of plastic additives. However, the key structure–activity relationships governing metal oxide-mediated transformation processes remain poorly understood. Here, we demonstrate that oxygen vacancies (OVs), which are common in metal oxide nanomaterials, significantly contribute to the enhanced catalytic performance of α-MnO2 nanoparticles in promoting the hydrolysis of 4-nitrophenyl phosphate (pNPP), a model OPE pollutant. The α-MnO2 nanorods containing different OV concentrations (obtained by calcination under different atmospheres, i.e., N2 versus air) promote pNPP hydrolysis to different degrees, and the α-MnO2 material with a higher OV concentration shows higher catalytic activity. The results from spectroscopic and theoretical investigations reveal that OVs regulate the adsorption affinity to pNPP by adjusting the coordination saturation of the Mn site on the α-MnO2 surface. Additionally, the enhanced Lewis acidity at these sites (as confirmed by pyridine adsorption infrared spectroscopy and temperature-programmed desorption of ammonia) promotes the electron redistribution in pNPP, which decreases the stability of the P–O bond and enhances the reactivity of α-MnO2 towards pNPP. The findings demonstrate that metal oxide nanomaterials can significantly influence the fate and transformation of microplastic additives, and highlight the potential of defect engineering in amplifying metal oxides’ efficacy for environmental cleanup.
{"title":"Oxygen vacancies boost the efficacy of MnO2 nanoparticles in catalyzing hydrolytic degradation of organophosphate esters: Implications for managing plastic additive pollution","authors":"Zongsheng Liang, keman liu, Yueyue Li, Yaqi Liu, Chuanjia Jiang, Tong Zhang, Wei Chen","doi":"10.1039/d4en00911h","DOIUrl":"https://doi.org/10.1039/d4en00911h","url":null,"abstract":"The widespread plastic pollution has raised significant concerns. The breakdown process of plastic debris during weathering not only generate microplastics and nanoplastics, but also release large quantities of harmful chemical additives such as phthalates and organophosphate esters (OPEs). Metal oxides, particularly those in the form of nanoparticles, play an essential role in mediating the environmental transformation of plastic additives. However, the key structure–activity relationships governing metal oxide-mediated transformation processes remain poorly understood. Here, we demonstrate that oxygen vacancies (OVs), which are common in metal oxide nanomaterials, significantly contribute to the enhanced catalytic performance of α-MnO2 nanoparticles in promoting the hydrolysis of 4-nitrophenyl phosphate (pNPP), a model OPE pollutant. The α-MnO2 nanorods containing different OV concentrations (obtained by calcination under different atmospheres, i.e., N2 versus air) promote pNPP hydrolysis to different degrees, and the α-MnO2 material with a higher OV concentration shows higher catalytic activity. The results from spectroscopic and theoretical investigations reveal that OVs regulate the adsorption affinity to pNPP by adjusting the coordination saturation of the Mn site on the α-MnO2 surface. Additionally, the enhanced Lewis acidity at these sites (as confirmed by pyridine adsorption infrared spectroscopy and temperature-programmed desorption of ammonia) promotes the electron redistribution in pNPP, which decreases the stability of the P–O bond and enhances the reactivity of α-MnO2 towards pNPP. The findings demonstrate that metal oxide nanomaterials can significantly influence the fate and transformation of microplastic additives, and highlight the potential of defect engineering in amplifying metal oxides’ efficacy for environmental cleanup.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"37 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yingnan Huang, Huijun Yan, Fei Dang, Zhenyu Wang, Jason C. White, Yujun Wang
The current and continued influx of engineered nanoparticles (NPs) into the environment is significant, including the release of NPs that have been historically stored or retained in soils to various waterbodies. However, the reactivity and dynamic nature of NPs transformation processes are poorly understood due to the lack of long-term environmentally relevant experiments that accurately represent ecosystem complexity. Here, we established a two-year mesocosm system to quantify the relative reactivity of silver sulfide NPs using stable isotope tracers, with more recent 109Ag2S-NPs inputs to the 80 L water column (water-borne NPs, 141 mg) and historically stored Ag2S-NPs in soils (soil-borne NPs, 4.5 ± 0.3 μg g−1). Soil-borne NPs accounted for 59.4–92.1% of the Ag accumulation in the grain of rice Oryza sativa L. (31.4–112.4 μg kg−1), radish roots Raphanus sativus L. (106.2–396.7 μg kg−1), and rice borers Chilo suppressalis (21.5–30.7 μg kg−1), highlighting the significance of soil-borne NPs in agricultural ecosystems. Based on the measured soil-to-plant transfer factors, recommended concentrations of soil-borne NPs should be less than 2.4 μg Ag g−1 for rice growth and 0.7 μg Ag g−1 for radish growth to minimize human exposure to silver via consumption of these edible tissues. This work demonstrates that quantifying the reactivity of NPs transformation processes and different NPs fractions in the environment is not only important to accurately characterizing the risk of these materials but also to ensuring the safety and sustainability of agriculture.
{"title":"Solid Phase Silver Sulfide Nanoparticles Contribute Significantly to Biotic Silver in Agricultural Systems","authors":"Yingnan Huang, Huijun Yan, Fei Dang, Zhenyu Wang, Jason C. White, Yujun Wang","doi":"10.1039/d4en00961d","DOIUrl":"https://doi.org/10.1039/d4en00961d","url":null,"abstract":"The current and continued influx of engineered nanoparticles (NPs) into the environment is significant, including the release of NPs that have been historically stored or retained in soils to various waterbodies. However, the reactivity and dynamic nature of NPs transformation processes are poorly understood due to the lack of long-term environmentally relevant experiments that accurately represent ecosystem complexity. Here, we established a two-year mesocosm system to quantify the relative reactivity of silver sulfide NPs using stable isotope tracers, with more recent 109Ag2S-NPs inputs to the 80 L water column (water-borne NPs, 141 mg) and historically stored Ag2S-NPs in soils (soil-borne NPs, 4.5 ± 0.3 μg g−1). Soil-borne NPs accounted for 59.4–92.1% of the Ag accumulation in the grain of rice Oryza sativa L. (31.4–112.4 μg kg−1), radish roots Raphanus sativus L. (106.2–396.7 μg kg−1), and rice borers Chilo suppressalis (21.5–30.7 μg kg−1), highlighting the significance of soil-borne NPs in agricultural ecosystems. Based on the measured soil-to-plant transfer factors, recommended concentrations of soil-borne NPs should be less than 2.4 μg Ag g−1 for rice growth and 0.7 μg Ag g−1 for radish growth to minimize human exposure to silver via consumption of these edible tissues. This work demonstrates that quantifying the reactivity of NPs transformation processes and different NPs fractions in the environment is not only important to accurately characterizing the risk of these materials but also to ensuring the safety and sustainability of agriculture.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"16 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a novel Ce-doped hydrotalcite (Ce-NiFe-LDHs) was synthesized by co-precipitation, which completely removed tetracycline hydrochloride (TC-HCl) in the photo-Fenton system within 60 min, and showed excellent stability and durability in cycling tests. In addition, the catalyst has demonstrated a wide range of adaptability to environmental conditions in the photo-Fenton system, maintaining efficient catalytic performance regardless of water quality differences, environmental factors or different types of antibiotics. The introduction of rare earth element Ce can not only effectively reduce the band gap width of the catalyst and broaden its absorption capacity in the visible light range, but also promote the efficient migration and separation of photogenerated carriers by optimizing the optical properties, further improving the catalytic efficiency. The free radical quenching experiment and electron spin resonance test revealed the core role of photogenerated hole as the main active substance. Combined with high performance liquid chromatography-mass spectrometry and density functional theory calculations, the degradation pathways were proposed. Meantime, through the Toxicity Estimation Software Tool and germination and growth test of soybean, it was found that the reaction was a process of toxicity reduction. This study provides a new strategy and theoretical basis for the future study of heterogeneous catalytic decomposition of antibiotic residues.
本研究通过共沉淀法合成了一种新型掺杂铈的水滑石（Ce-NiFe-LDHs），该催化剂在光-芬顿体系中可在 60 分钟内完全去除盐酸四环素（TC-HCl），并在循环测试中表现出优异的稳定性和耐久性。此外，该催化剂对光-芬顿体系中的环境条件具有广泛的适应性，无论水质差异、环境因素或不同类型的抗生素如何变化，都能保持高效的催化性能。稀土元素 Ce 的引入不仅能有效降低催化剂的带隙宽度，拓宽其在可见光范围内的吸收能力，还能通过优化光学特性促进光生载流子的高效迁移和分离，进一步提高催化效率。自由基淬灭实验和电子自旋共振测试揭示了光生空穴作为主要活性物质的核心作用。结合高效液相色谱-质谱分析和密度泛函理论计算，提出了降解途径。同时，通过毒性估算软件工具和大豆发芽生长试验，发现该反应是一个毒性降低的过程。该研究为今后研究抗生素残留的异相催化分解提供了新的策略和理论依据。
{"title":"A novel Ce-doped hydrotalcite for the efficient removal of tetracycline hydrochloride in the photo-Fenton system: from properties to mechanisms","authors":"Yanshu Chen, Xia Liu, Ximan Wang, Shuanghui Sun, Yunfeng Wu, Siqi Bao, Lei Xu","doi":"10.1039/d4en00865k","DOIUrl":"https://doi.org/10.1039/d4en00865k","url":null,"abstract":"In this study, a novel Ce-doped hydrotalcite (Ce-NiFe-LDHs) was synthesized by co-precipitation, which completely removed tetracycline hydrochloride (TC-HCl) in the photo-Fenton system within 60 min, and showed excellent stability and durability in cycling tests. In addition, the catalyst has demonstrated a wide range of adaptability to environmental conditions in the photo-Fenton system, maintaining efficient catalytic performance regardless of water quality differences, environmental factors or different types of antibiotics. The introduction of rare earth element Ce can not only effectively reduce the band gap width of the catalyst and broaden its absorption capacity in the visible light range, but also promote the efficient migration and separation of photogenerated carriers by optimizing the optical properties, further improving the catalytic efficiency. The free radical quenching experiment and electron spin resonance test revealed the core role of photogenerated hole as the main active substance. Combined with high performance liquid chromatography-mass spectrometry and density functional theory calculations, the degradation pathways were proposed. Meantime, through the Toxicity Estimation Software Tool and germination and growth test of soybean, it was found that the reaction was a process of toxicity reduction. This study provides a new strategy and theoretical basis for the future study of heterogeneous catalytic decomposition of antibiotic residues.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"8 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karolina Solymos, Eszter Kanász, Áron Ágoston, Tamás Gyulavári, Benjámin Pálffy, Ákos Szamosvölgyi, Akos Kukovecz, Zoltan Konya, Zsolt Pap
Zinc oxide (ZnO) nanoparticles are extensively utilized across various industries due to their versatile applications. However, the widespread use of these nanoparticles raises concerns regarding their potential release into soil environments, and also into the soil solution. Therefore, this study aims to delve into the interplay between different soil solution properties and the stability as well as photocatalytic activity of commercially available ZnO nanoparticles. It is observed that these interactions precipitate a reduction in the primary crystallite sizes of ZnO, primarily attributed to the release of Zn2+ ions under acidic conditions, and the formation of zinc complexes or hydroxides in alkaline environments. In acidic media, there is a concomitant decrease in the hydrodynamic diameter of ZnO, serving as further confirmation of Zn2+ release, which is corroborated by analytical measurements. Conversely, in alkaline mediums, the hydrodynamic diameter remains unaltered, suggesting the formation of an amorphous layer on the nanoparticle surface in such conditions. Further analyses into the surface chemistry of ZnO nanoparticles reveal the adsorption of various organic substances onto their surfaces. These organic compounds potentially function as electron traps or occupy active sites, however, after the interaction with soil solutions, the material was still able to degrade the model pollutant. So, the interaction with soil solutions reduced the activity, but the catalyst retained its efficiency. In essence, this study underscores the importance of comprehensively understanding the behavior of ZnO nanoparticles in soil environments. Such insights are pivotal for informed decision-making regarding the sustainable utilization of ZnO nanoparticles across various industrial domains.
{"title":"Impact of Different Soil Solutions on the Stability and Photocatalytic Activity of Commercial Zinc Oxide Nanoparticles","authors":"Karolina Solymos, Eszter Kanász, Áron Ágoston, Tamás Gyulavári, Benjámin Pálffy, Ákos Szamosvölgyi, Akos Kukovecz, Zoltan Konya, Zsolt Pap","doi":"10.1039/d4en00354c","DOIUrl":"https://doi.org/10.1039/d4en00354c","url":null,"abstract":"Zinc oxide (ZnO) nanoparticles are extensively utilized across various industries due to their versatile applications. However, the widespread use of these nanoparticles raises concerns regarding their potential release into soil environments, and also into the soil solution. Therefore, this study aims to delve into the interplay between different soil solution properties and the stability as well as photocatalytic activity of commercially available ZnO nanoparticles. It is observed that these interactions precipitate a reduction in the primary crystallite sizes of ZnO, primarily attributed to the release of Zn2+ ions under acidic conditions, and the formation of zinc complexes or hydroxides in alkaline environments. In acidic media, there is a concomitant decrease in the hydrodynamic diameter of ZnO, serving as further confirmation of Zn2+ release, which is corroborated by analytical measurements. Conversely, in alkaline mediums, the hydrodynamic diameter remains unaltered, suggesting the formation of an amorphous layer on the nanoparticle surface in such conditions. Further analyses into the surface chemistry of ZnO nanoparticles reveal the adsorption of various organic substances onto their surfaces. These organic compounds potentially function as electron traps or occupy active sites, however, after the interaction with soil solutions, the material was still able to degrade the model pollutant. So, the interaction with soil solutions reduced the activity, but the catalyst retained its efficiency. In essence, this study underscores the importance of comprehensively understanding the behavior of ZnO nanoparticles in soil environments. Such insights are pivotal for informed decision-making regarding the sustainable utilization of ZnO nanoparticles across various industrial domains.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"27 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhoujie Pi, Puyu Zhou, Kun Luo, Li He, Shengjie Chen, Zhu Wang, Shanshan Zhang, Xiaoming Li, Qi Yang
Chlorophenols (CPs) have strong toxicity because of the presence of chlorine atom. Although the dechlorination can eliminate their toxicity, by-product organics maybe bring secondary pollution. In this study, a two-step process of pre-reduction dechlorination and oxidation, reductive dechlorination by sulfidated nanoscale zero-valent iron (S-nZVI) and advanced oxidation by S-nZVI-activated peroxydisulfate (PDS), was innovatively adopted to achieve efficient and complete mineralization of 2,4-dichlorophenol (2,4-DCP). The pre-reduction of S-nZVI achieved 80% dechlorination of 2,4-DCP. With the subsequent addition of PDS, 2,4-DCP and its dechlorination by-products in solution was almost completely removed and the mineralization rate reached to 91.5% under the optimal conditions of unadjusted initial pH (5.4), S-nZVI dosage 2.5 g·L-1, and PDS concentration 1.8 mM. The electron spin resonance (ESR) and radical quenching experiments demonstrated that both ·OH and SO4·- were involved in the degradation of 2,4-DCP, while SO4·- played the more predominate role. Based on the transformation products of 2,4-DCP identified by GC-MS, the degradation mechanism of 2,4-DCP in this system included two steps, namely, reductive dechlorination induced by electrons transformation and oxidation degradation involving single electron transfer, radical adduct formation, and hydrogen atom abstraction. This study demonstrated that the noval S-nZVI pre-reduction and sequential S-nZVI/PDS process is a very promising and efficient approach for complete removal of CPs in water.
{"title":"Complete degradation of 2,4-dichlorophenol in sequential sulfidated nanoscale zero-valent iron/peroxydisulfate system: Dechlorination, mineralization and mechanism","authors":"Zhoujie Pi, Puyu Zhou, Kun Luo, Li He, Shengjie Chen, Zhu Wang, Shanshan Zhang, Xiaoming Li, Qi Yang","doi":"10.1039/d4en00737a","DOIUrl":"https://doi.org/10.1039/d4en00737a","url":null,"abstract":"Chlorophenols (CPs) have strong toxicity because of the presence of chlorine atom. Although the dechlorination can eliminate their toxicity, by-product organics maybe bring secondary pollution. In this study, a two-step process of pre-reduction dechlorination and oxidation, reductive dechlorination by sulfidated nanoscale zero-valent iron (S-nZVI) and advanced oxidation by S-nZVI-activated peroxydisulfate (PDS), was innovatively adopted to achieve efficient and complete mineralization of 2,4-dichlorophenol (2,4-DCP). The pre-reduction of S-nZVI achieved 80% dechlorination of 2,4-DCP. With the subsequent addition of PDS, 2,4-DCP and its dechlorination by-products in solution was almost completely removed and the mineralization rate reached to 91.5% under the optimal conditions of unadjusted initial pH (5.4), S-nZVI dosage 2.5 g·L-1, and PDS concentration 1.8 mM. The electron spin resonance (ESR) and radical quenching experiments demonstrated that both ·OH and SO4·- were involved in the degradation of 2,4-DCP, while SO4·- played the more predominate role. Based on the transformation products of 2,4-DCP identified by GC-MS, the degradation mechanism of 2,4-DCP in this system included two steps, namely, reductive dechlorination induced by electrons transformation and oxidation degradation involving single electron transfer, radical adduct formation, and hydrogen atom abstraction. This study demonstrated that the noval S-nZVI pre-reduction and sequential S-nZVI/PDS process is a very promising and efficient approach for complete removal of CPs in water.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"20 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142690955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the development of persulfate-based Fenton-like catalysis, how to control the PDS reaction pathway is a great challenge. Herein, we prepared catalysts with nitrogen-rich porous carbon (NPC) layers and oxygen vacancy (Ov) sites for PDS activation to degrade sulfamethazine (SMZ). Results revealed that the ZnO@NPC/PDS system exhibited only non-radical pathways, which comprised the singlet oxygen (1O2) and electron transfer process. The intrinsic mechanism underlying the production of active species was further verified by comparing the results of the ZnO@NPC/PDS and ZnO@NPC-Etch/PDS systems, Raman analysis and DFT calculations. Adsorption of PDS by carbon layers resulted in the formation of a catalyst–PDS complex, which not only elongated the S–O bond and accelerated the decomposition of PDS to generate 1O2 but also provided access for electron transfer. Meanwhile, Ov sites increased electron density and electron migration strength, which promoted more electron transfer from Ovs to PDS molecules through nitrogen-rich porous carbon layers. Moreover, the ZnO@NPC/PDS system could maintain a degradation rate of >90% for SMZ in real water matrixes. T. E. S. T software prediction and toxicity tests were used to investigate environmental implications of degradation intermediates, which showed reduced ecological toxicity compared with SMZ. This work fabricated the ZnO@NPC/PDS system and explored the interaction between nitrogen-rich porous carbon layers and Ov to regulate the occurrence of non-radical pathways, which could provide a strategy to control the PDS reaction pathway.
随着基于过硫酸盐的 Fenton-like 催化技术的发展，如何控制 PDS 反应途径是一个巨大的挑战。在此，我们制备了具有富氮多孔碳（NPC）层和氧空位（Ov）的催化剂，用于活化 PDS 以降解磺胺二甲嘧啶（SMZ）。结果表明，ZnO@NPC/PDS体系只表现出非自由基途径，包括单线态氧（1O2）和电子转移过程。通过比较 ZnO@NPC/PDS 和 ZnO@NPC-Etch/PDS 系统、拉曼分析和 DFT 计算的结果，进一步验证了活性物种产生的内在机制。碳层对 PDS 的吸附导致催化剂-PDS 复合物的形成，这不仅拉长了 S-O 键，加速 PDS 分解生成 1O2，还为电子转移提供了通道。同时，Ov位点增加了电子密度和电子迁移强度，促进了更多电子通过富氮多孔碳层从Ov转移到PDS分子。此外，ZnO@NPC/PDS 系统在实际水基质中对 SMZ 的降解率可达 90%。利用 T. E. S. T 软件预测和毒性测试研究了降解中间产物对环境的影响，结果表明与 SMZ 相比，降解中间产物的生态毒性有所降低。这项工作制备了 ZnO@NPC/PDS 系统，并探索了富氮多孔碳层与 Ov 之间的相互作用，以调节非自由基途径的发生，从而为控制 PDS 反应途径提供了一种策略。
{"title":"Optimization of Fenton-like reaction pathways using Ov-containing ZnO@nitrogen-rich porous carbon: the electron transfer and 1O2 triggered non-radical process","authors":"Zhenfeng Zhang, Tianli Xiong, Haihao Peng, Honglin Zhang, Siying He, Xuran Liu, Yanan Liu, Wenyi Feng, Zhaohui Yang, Weiping Xiong","doi":"10.1039/d4en00749b","DOIUrl":"https://doi.org/10.1039/d4en00749b","url":null,"abstract":"With the development of persulfate-based Fenton-like catalysis, how to control the PDS reaction pathway is a great challenge. Herein, we prepared catalysts with nitrogen-rich porous carbon (NPC) layers and oxygen vacancy (O<small><sub>v</sub></small>) sites for PDS activation to degrade sulfamethazine (SMZ). Results revealed that the ZnO@NPC/PDS system exhibited only non-radical pathways, which comprised the singlet oxygen (<small><sup>1</sup></small>O<small><sub>2</sub></small>) and electron transfer process. The intrinsic mechanism underlying the production of active species was further verified by comparing the results of the ZnO@NPC/PDS and ZnO@NPC-Etch/PDS systems, Raman analysis and DFT calculations. Adsorption of PDS by carbon layers resulted in the formation of a catalyst–PDS complex, which not only elongated the S–O bond and accelerated the decomposition of PDS to generate <small><sup>1</sup></small>O<small><sub>2</sub></small> but also provided access for electron transfer. Meanwhile, O<small><sub>v</sub></small> sites increased electron density and electron migration strength, which promoted more electron transfer from O<small><sub>v</sub></small>s to PDS molecules through nitrogen-rich porous carbon layers. Moreover, the ZnO@NPC/PDS system could maintain a degradation rate of >90% for SMZ in real water matrixes. T. E. S. T software prediction and toxicity tests were used to investigate environmental implications of degradation intermediates, which showed reduced ecological toxicity compared with SMZ. This work fabricated the ZnO@NPC/PDS system and explored the interaction between nitrogen-rich porous carbon layers and O<small><sub>v</sub></small> to regulate the occurrence of non-radical pathways, which could provide a strategy to control the PDS reaction pathway.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"129 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hematite displays diverse crystal structures and often coexists with Fe(Ⅱ), both of which are crucial in controlling the fate and mobility of Cr(Ⅵ). However, the mechanisms underlying Cr(Ⅵ) removal in the presence of Fe(Ⅱ) on various hematite facets remain elusive. This study aims to elucidate the facet-dependent reactivity of hematite nanocrystals in conjunction with Fe(Ⅱ) for the removal Cr(Ⅵ) from aqueous solutions. Hematite nanoplates (HNPs), predominantly composed of {001} facets, and nanorods (HNRs), exposing both {001} and {110} facets, were synthesized and characterized. Their Cr(VI) removal capabilities were evaluated in hematite-Cr(VI) and hematite-Fe(II)-Cr(VI) systems, as well as the Fe(II)-Cr(VI) system. The adsorption of Fe(Ⅱ) and Cr(VI) on hematite surfaces was highly dependent on the crystal facets and pH, with HNRs demonstrating superior Cr(Ⅵ) adsorption over HNPs, especially under acidic conditions. Neutral pH favored Fe(II)-Cr(VI) redox reactions and Fe(II) adsorption. The hematite-Fe(Ⅱ) couple displayed a synergistic effect in removing Cr(Ⅵ) under acidic conditions, which was not observed under neutral conditions. The presence of Fe(Ⅱ) notably enhanced Cr(Ⅵ) adsorption onto hematite, and bound Fe(Ⅱ) facilitated electron transfer, accelerating Cr(Ⅵ) reduction. HNRs-Fe(Ⅱ) exhibited higher Cr(Ⅵ) removal efficiency than HNPs-Fe(Ⅱ) due to their lower free corrosion potential and improved electron transport properties. This research underscores the potential of facet engineering in optimizing hematite nanocrystals for environmental remediation, specifically in Cr(Ⅵ)-contaminated environments.
{"title":"Facet-Dependent Hematite Reactivity in Cr(Ⅵ) Removal with Fe(Ⅱ)","authors":"Shengnan Zhang, Lingyi Li, Junxue Li, Wei Cheng","doi":"10.1039/d4en00733f","DOIUrl":"https://doi.org/10.1039/d4en00733f","url":null,"abstract":"Hematite displays diverse crystal structures and often coexists with Fe(Ⅱ), both of which are crucial in controlling the fate and mobility of Cr(Ⅵ). However, the mechanisms underlying Cr(Ⅵ) removal in the presence of Fe(Ⅱ) on various hematite facets remain elusive. This study aims to elucidate the facet-dependent reactivity of hematite nanocrystals in conjunction with Fe(Ⅱ) for the removal Cr(Ⅵ) from aqueous solutions. Hematite nanoplates (HNPs), predominantly composed of {001} facets, and nanorods (HNRs), exposing both {001} and {110} facets, were synthesized and characterized. Their Cr(VI) removal capabilities were evaluated in hematite-Cr(VI) and hematite-Fe(II)-Cr(VI) systems, as well as the Fe(II)-Cr(VI) system. The adsorption of Fe(Ⅱ) and Cr(VI) on hematite surfaces was highly dependent on the crystal facets and pH, with HNRs demonstrating superior Cr(Ⅵ) adsorption over HNPs, especially under acidic conditions. Neutral pH favored Fe(II)-Cr(VI) redox reactions and Fe(II) adsorption. The hematite-Fe(Ⅱ) couple displayed a synergistic effect in removing Cr(Ⅵ) under acidic conditions, which was not observed under neutral conditions. The presence of Fe(Ⅱ) notably enhanced Cr(Ⅵ) adsorption onto hematite, and bound Fe(Ⅱ) facilitated electron transfer, accelerating Cr(Ⅵ) reduction. HNRs-Fe(Ⅱ) exhibited higher Cr(Ⅵ) removal efficiency than HNPs-Fe(Ⅱ) due to their lower free corrosion potential and improved electron transport properties. This research underscores the potential of facet engineering in optimizing hematite nanocrystals for environmental remediation, specifically in Cr(Ⅵ)-contaminated environments.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"46 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Svetlana Vihodceva, Andris Šutka, Mairis Iesalnieks, Liga Orlova, Arturs Pludonis, Maarja Otsus, Mariliis Sihtmäe, Heiki Vija, Alexandra Nefedova, Angela Ivask, Anne Kahru, Kaja Kasemets
This research presents a synthesis method for the CeO<small><sub>2</sub></small>/CuO nanostructured composite, which has potential applications as an antimicrobial material in the production of antimicrobial surface coatings, for example, for high-touch surfaces. The antimicrobial efficacy, mode of action, and potential cytotoxicity of CeO<small><sub>2</sub></small>/CuO towards the human immortalized keratinocyte cell line <em>in vitro</em> were studied compared to those of CuO, CeO<small><sub>2</sub></small>, and ionic Cu (a solubility control). The used synthesis method resulted in a CeO<small><sub>2</sub></small>/CuO nanostructured composite with a mean particle size of 27 nm and a specific surface area of 80.3 m<small><sup>2</sup></small> g<small><sup>−1</sup></small>. The composite had a significant proportion (54%) of non-lattice oxygen species, highlighting the presence of substantial surface defects crucial for generating reactive oxygen species (ROS). The antimicrobial properties of CeO<small><sub>2</sub></small>/CuO, CuO, and CeO<small><sub>2</sub></small> were assessed at six concentrations from 1 to 1000 mg L<small><sup>−1</sup></small> in deionized water. The CeO<small><sub>2</sub></small>/CuO composite exhibited antibacterial efficacy at a minimum bactericidal concentration (MBC) of 100 mg L<small><sup>−1</sup></small> towards <em>Escherichia coli</em> already after 2 h of contact and towards <em>Pseudomonas aeruginosa</em> and <em>Staphylococcus aureus</em> after 4 h of contact, whereas after 24 h of exposure, the antibacterial efficacy to all three bacterial strains was evident already at a MBC = 10 mg L<small><sup>−1</sup></small>. Fungi <em>Candida albicans</em> proved less susceptible than bacteria (24 h MBC = 100 mg L<small><sup>−1</sup></small>). Thus, the CeO<small><sub>2</sub></small>/CuO composite showed significant antibacterial efficacy against Gram-negative and Gram-positive bacteria, being at the same time safe to human keratinocytes <em>in vitro</em> in the case of which even 1000 mg L<small><sup>−1</sup></small> caused no harmful effects after 2 h exposure and 500 mg L<small><sup>−1</sup></small> caused no cytotoxicity after 24 h exposure. CeO<small><sub>2</sub></small>/CuO caused abiotic and biotic ROS production in all the tested environments. ROS production in deionized water was the most remarkable. Shedding of Cu-ions from CeO<small><sub>2</sub></small>/CuO was moderate and depended on the test environment, varying from 0.3 to 1 mg L<small><sup>−1</sup></small>, and considering the MBC of ionic Cu for microorganisms was not the main contributor to the antimicrobial activity of CeO<small><sub>2</sub></small>/CuO. The CeO<small><sub>2</sub></small>/CuO composite exhibited no acute toxicity to the environmentally relevant bacterium <em>Vibrio fischeri</em>. These findings indicate that CeO<small><sub>2</sub></small>/CuO's high ROS production is its primary antimicrobial mechanism and that due to its low cytotoxicit
{"title":"Emerging investigator series: CeO2/CuO nanostructured composite with enhanced antimicrobial properties and low cytotoxicity to human keratinocytes in vitro","authors":"Svetlana Vihodceva, Andris Šutka, Mairis Iesalnieks, Liga Orlova, Arturs Pludonis, Maarja Otsus, Mariliis Sihtmäe, Heiki Vija, Alexandra Nefedova, Angela Ivask, Anne Kahru, Kaja Kasemets","doi":"10.1039/d4en00501e","DOIUrl":"https://doi.org/10.1039/d4en00501e","url":null,"abstract":"This research presents a synthesis method for the CeO<small><sub>2</sub></small>/CuO nanostructured composite, which has potential applications as an antimicrobial material in the production of antimicrobial surface coatings, for example, for high-touch surfaces. The antimicrobial efficacy, mode of action, and potential cytotoxicity of CeO<small><sub>2</sub></small>/CuO towards the human immortalized keratinocyte cell line <em>in vitro</em> were studied compared to those of CuO, CeO<small><sub>2</sub></small>, and ionic Cu (a solubility control). The used synthesis method resulted in a CeO<small><sub>2</sub></small>/CuO nanostructured composite with a mean particle size of 27 nm and a specific surface area of 80.3 m<small><sup>2</sup></small> g<small><sup>−1</sup></small>. The composite had a significant proportion (54%) of non-lattice oxygen species, highlighting the presence of substantial surface defects crucial for generating reactive oxygen species (ROS). The antimicrobial properties of CeO<small><sub>2</sub></small>/CuO, CuO, and CeO<small><sub>2</sub></small> were assessed at six concentrations from 1 to 1000 mg L<small><sup>−1</sup></small> in deionized water. The CeO<small><sub>2</sub></small>/CuO composite exhibited antibacterial efficacy at a minimum bactericidal concentration (MBC) of 100 mg L<small><sup>−1</sup></small> towards <em>Escherichia coli</em> already after 2 h of contact and towards <em>Pseudomonas aeruginosa</em> and <em>Staphylococcus aureus</em> after 4 h of contact, whereas after 24 h of exposure, the antibacterial efficacy to all three bacterial strains was evident already at a MBC = 10 mg L<small><sup>−1</sup></small>. Fungi <em>Candida albicans</em> proved less susceptible than bacteria (24 h MBC = 100 mg L<small><sup>−1</sup></small>). Thus, the CeO<small><sub>2</sub></small>/CuO composite showed significant antibacterial efficacy against Gram-negative and Gram-positive bacteria, being at the same time safe to human keratinocytes <em>in vitro</em> in the case of which even 1000 mg L<small><sup>−1</sup></small> caused no harmful effects after 2 h exposure and 500 mg L<small><sup>−1</sup></small> caused no cytotoxicity after 24 h exposure. CeO<small><sub>2</sub></small>/CuO caused abiotic and biotic ROS production in all the tested environments. ROS production in deionized water was the most remarkable. Shedding of Cu-ions from CeO<small><sub>2</sub></small>/CuO was moderate and depended on the test environment, varying from 0.3 to 1 mg L<small><sup>−1</sup></small>, and considering the MBC of ionic Cu for microorganisms was not the main contributor to the antimicrobial activity of CeO<small><sub>2</sub></small>/CuO. The CeO<small><sub>2</sub></small>/CuO composite exhibited no acute toxicity to the environmentally relevant bacterium <em>Vibrio fischeri</em>. These findings indicate that CeO<small><sub>2</sub></small>/CuO's high ROS production is its primary antimicrobial mechanism and that due to its low cytotoxicit","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"34 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Enhancing the efficiency of electron transfer and augmenting the utilization rate of peroxymonosulfate (PMS) pose challenges for advanced oxidation processes (AOPs). A high-performance bimetallic-doped catalyst (MnCo/CeO2) with an appropriate concentration of oxygen vacancies (OVs) was successfully designed using a straightforward synthesis strategy. It primarily activates PMS through non-radical pathways. Systemic characterization, experiments, and theoretical calculations have demonstrated that reasonable OVs and the Mn/Co bimetallic doping strategy effectively modulated the surface spatial electron structure and greatly improved interfacial electron transfer processes (ETP). Ultimately, MnCo/CeO2 exhibits a remarkable ciprofloxacin (CIP) removal efficiency of 93.71% (k = 0.03501 min−1) within 50 min (after 5 cycles, 89%), which is 5.03 times faster than that of traditional CeO2 (k = 0.00696 min−1), and the possible degradation pathway as well as toxicity of intermediate products were identified using LC-MS, Fukui function analysis, and toxicity evaluation. This work proposes a feasible strategy for designing bimetallic-doped metallic oxide catalysts, which have great application potential for the degradation of organic contaminants under actual harsh environmental conditions.
{"title":"Optimizing oxygen vacancy concentration and electronic transport processes in a MnxCo/CeO2 nanoreactor: regulation mechanism of the radical to non-radical pathway","authors":"Hailan Qin, Jiahao Wang, Siyuan Di, Yunkang Liu, Pin Chen, Min Liu, Qiuyue Zhang, Shukui Zhu","doi":"10.1039/d4en00892h","DOIUrl":"https://doi.org/10.1039/d4en00892h","url":null,"abstract":"Enhancing the efficiency of electron transfer and augmenting the utilization rate of peroxymonosulfate (PMS) pose challenges for advanced oxidation processes (AOPs). A high-performance bimetallic-doped catalyst (MnCo/CeO<small><sub>2</sub></small>) with an appropriate concentration of oxygen vacancies (OVs) was successfully designed using a straightforward synthesis strategy. It primarily activates PMS through non-radical pathways. Systemic characterization, experiments, and theoretical calculations have demonstrated that reasonable OVs and the Mn/Co bimetallic doping strategy effectively modulated the surface spatial electron structure and greatly improved interfacial electron transfer processes (ETP). Ultimately, MnCo/CeO<small><sub>2</sub></small> exhibits a remarkable ciprofloxacin (CIP) removal efficiency of 93.71% (<em>k</em> = 0.03501 min<small><sup>−1</sup></small>) within 50 min (after 5 cycles, 89%), which is 5.03 times faster than that of traditional CeO<small><sub>2</sub></small> (<em>k</em> = 0.00696 min<small><sup>−1</sup></small>), and the possible degradation pathway as well as toxicity of intermediate products were identified using LC-MS, Fukui function analysis, and toxicity evaluation. This work proposes a feasible strategy for designing bimetallic-doped metallic oxide catalysts, which have great application potential for the degradation of organic contaminants under actual harsh environmental conditions.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"13 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Opened multiwalled carbon nanotubes (O-MWCNT) were prepared by unzipping MWCNTs using Hummers' method and decorated with CuO to form a nanohybrid (O-MWCNT/CuO) through a simple co-precipitation technique, aimed at developing a novel electrochemical sensor. The O-MWCNT/CuO composite was used to modify a glassy carbon electrode (GCE) for the sensitive detection of the antipyretic drug acetaminophen (ACT) in various matrices. O-MWCNT/CuO was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS), which confirmed the successful formation of the nanocomposite as well as its electrical conductivity and catalytic properties. The sensor demonstrates a wide linear detection range (0.005–1450 μM), with a low detection limit (LOD) of 7.2 nM and excellent sensitivity of 0.019 μA cm−2 μM−1. Additionally, the sensor demonstrated good stability (maintaining performance over 65 cycles) and selectivity in various co-interfering compounds. Notably, the electrochemical sensor was applied for the detection of ACT in environmental water samples, pharmaceutical formulations, human biological fluids, and fenugreek plant extracts, achieving good recovery rates (97.37–100.20%) with relative standard deviations (RSD) ranging from 1.0% to 3.3%, using the standard addition method. The novelty of this work lies in the development of a highly sensitive, stable, and selective GCE-modified sensor for ACT detection, with promising applications in real-world sample analysis.
{"title":"Electrochemical investigation of an antipyretic drug in plant extracts and environmental samples at the O-MWCNT/CuO nanostructure modified glassy carbon electrode","authors":"Yesurajan Allwin Richard, Sebastinbaskar Aniu Lincy, An-Ya Lo, Chelliah Koventhan, Venkataraman Dharuman, Shakkthivel Piraman","doi":"10.1039/d4en00454j","DOIUrl":"https://doi.org/10.1039/d4en00454j","url":null,"abstract":"Opened multiwalled carbon nanotubes (O-MWCNT) were prepared by unzipping MWCNTs using Hummers' method and decorated with CuO to form a nanohybrid (O-MWCNT/CuO) through a simple co-precipitation technique, aimed at developing a novel electrochemical sensor. The O-MWCNT/CuO composite was used to modify a glassy carbon electrode (GCE) for the sensitive detection of the antipyretic drug acetaminophen (ACT) in various matrices. O-MWCNT/CuO was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS), which confirmed the successful formation of the nanocomposite as well as its electrical conductivity and catalytic properties. The sensor demonstrates a wide linear detection range (0.005–1450 μM), with a low detection limit (LOD) of 7.2 nM and excellent sensitivity of 0.019 μA cm<small><sup>−2</sup></small> μM<small><sup>−1</sup></small>. Additionally, the sensor demonstrated good stability (maintaining performance over 65 cycles) and selectivity in various co-interfering compounds. Notably, the electrochemical sensor was applied for the detection of ACT in environmental water samples, pharmaceutical formulations, human biological fluids, and fenugreek plant extracts, achieving good recovery rates (97.37–100.20%) with relative standard deviations (RSD) ranging from 1.0% to 3.3%, using the standard addition method. The novelty of this work lies in the development of a highly sensitive, stable, and selective GCE-modified sensor for ACT detection, with promising applications in real-world sample analysis.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"19 1","pages":""},"PeriodicalIF":8.131,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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