JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Liwei Yang,Fashan Yang,Heng Zhang,Hongyu Zhou,Mengfan Luo,Yunmei Liu,Chuanliang Zhao,Lu Zheng,Bo Lai
At present, the potential mechanism of manganese oxide (MnO 2 ) activation of PI and the key active sites of PI activation are still unclear and controversial. To this end, three different crystal forms of MnO 2 were prepared in this study and used to activate PI to degrade pollutants. The results showed that different crystal types of MnO 2 showed different catalytic abilities, and the order was γ-MnO 2 > α-MnO 2 > β-MnO 2 . Through quenching experiments, EPR tests, Raman experiments and in situ electrochemical experiments, it has been confirmed that electron transfer-mediated non-free radical process is the main mechanism of pollutant degradation , in which the active substance is the highly active metastable intermediate complex (MnO 2 /PI*). Hydroxyl radical (HO • ), superoxide radical (O 2 •− ), singlet oxygen ( 1 O 2 ) and iodine radical (IO 3 • ) did not participate in pollutant degradation. The quantitative structure-activity relationship analysis confirmed that the catalytic performance of MnO 2 was highly positively correlated with the surface Mn(IV) content, which indicated that the surface Mn(IV) site was the main active site. Overall, this study will be of great help to the design and application of manganese dioxide activation for periodate degradation of pollutants.
研究领域:
环境科学
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材料化学
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Ke Li,Yibing Sun,Jiawei Zhou,Xinyue Zhang,Hongchao Li,Zhichao Yang
The combination of transition metal oxides with carbon-based materials is a promising strategy for constructing efficient catalysts for peroxymonosulfate (PMS) activation to degrade aqueous organic contaminants. However, the complex heterostructure of the composites often hinders the identification of the actual reactive species responsible for pollutant degradation. In this study, we integrate Mn 3 O 4 into N-doped graphite (NG) to elucidate the mechanisms involved in the Mn-NG composite mediated PMS activation process. The Mn-NG/PMS system shows excellent performance in oxidizing bisphenol A (BPA) over a wide pH range (3.4 to 9.4) and in the presence of co-existing substrates. Mn sites in Mn 3 O 4 are responsible for the activation of PMS, and the NG matrix enhances the dispersion of Mn in the Mn-NG composite. Multiple experimental results indicate that free radicals (i.e., hydroxyl radicals (HO • ) and sulfate radicals (SO 4 •− )) are not generated, and surface reactive Mn(IV) is proposed as the primary reactive species for BPA oxidation. This study provides new insights into understanding the role of Mn oxides in carbon-based composites in PMS activation for degradation of organic pollutants.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2022
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IF 11.357
Hongchao Li,Na Yuan,Jieshu Qian,Bingcai Pan
The environmentally benign Mn oxides play a crucial role in the transformation of organic contaminants, either through catalytically decomposing oxidants, e.g., peroxymonosulfate (PMS), or through directly oxidizing the target pollutants. Because of their dual roles and the complex surface chemical reactions, the mechanism involved in Mn oxide-catalyzed PMS activation processes remains obscure. Here, we clearly elucidate the mechanism involved in the Mn2O3 catalyzed PMS activation process by means of separating the PMS activation and the pollutant oxidation process. Mn2O3 acts as a shuttle that mediates the electron transfer from organic substrates to PMS, accompanied by the redox cycle of surface Mn(IV)/Mn(III). Multiple experimental results indicate that PMS is bound to the surface of Mn2O3 to form an inner-sphere complex, which then decomposes to form long-lived surface reactive Mn(IV) species, without the generation of sulfate radicals (SO4•–) and hydroxyl radicals (HO•). The surface reactive Mn(IV) species are proposed to be responsible for the degradation of organic contaminants (e.g., phenol) and the formation of singlet oxygen (1O2), followed by the regeneration of the surface Mn(III) sites on Mn2O3. This study advances the fundamental understanding of the underlying mechanism involved in transition metal oxide-catalyzed PMS activation processes.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
Materials Today Chemistry
·
2022
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IF 7.613
X. Zhou,M.-H. Zhao,J. Yang,Y. Han,L. Cao,Y.-Y. Han,J. Wang,Y. Wang,M.-R. Li
Environment-friendly and cost-effective versatile yellow-green inorganic pigments are technically significant for natural camouflage but rare. Here, we adopt site-selective parent-doping of Mn–Li into the octahedral Ca-site (Ca B ) of Ca 3 TeO 6 to deliver vivid greenish pigments by the unprecedented yellow-green Mn 4+ O 6 chromophore, yielding tunable pigments resemble to seasonal leaves. The camouflage color zone of these pigments are remarkably enlarged by chemical pressure via Mg 2+ /Sr 2+ -substitution for the A -site Ca (Ca A ). The locally anisotropic and positive chemical pressure on chromophore group is scaled to be around +14.4/+23.3 GPa, as estimated from the accompanied geometric evolution of Mn 4+ O 6 . The achieved pigments also demonstrate excellent chemical and thermodynamic stability and high (60–80%) near infrared reflectivity in 1500–2500 nm, showing potential applications for natural camouflage and yellow-green “cool pigments”. These findings built a bridge between chemical and equivalently physical pressure, and nominated a way to estimate the overall and local strain/pressure by optical descriptor.
研究领域:
无机化学
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材料科学
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光学
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环境科学
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DOI
高影响因子
ACS ES&T Water
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2025
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IF 4.3
Xinyue Zhang,Zhichao Yang,Hongchao Li,Bingcai Pan
Transition-metal oxide-mediated peroxide activation systems have been demonstrated to initiate selective degradation of pollutants, while the underlying mechanism remains unclear and sometimes controversial. In this study, we systematically explored the reactive species/pathways for pollutant degradation in the Mn oxide octahedron molecular sieve (OMS-2)-triggered peracetic acid (PAA) activation system. By separating PAA activation and pollutant oxidation processes using a sequential activation/oxidation system or galvanic oxidation system, we confirm that the OMS-2/PAA system follows the reactive metal species mechanism, where surface reactive Mn(IV) species, rather than Mn–PAA complexes, are primarily responsible for the nonradical oxidation of bisphenol A. OMS-2 shows varied peroxide-activating activities (i.e., catalase-like and peroxidase-like activities) toward different peroxides (i.e., H2O2, PAA, and persulfates), depending on the reactivity of surface reactive Mn(IV) species with those peroxides. In addition, the long-lived surface reactive Mn(IV) species exhibit excellent resistance to fluctuations in solution pH and interference from coexisting anions and natural organic matter. This study offers novel insights into the nonradical mechanism involved in Mn oxide-mediated peroxide activation processes.
研究领域:
环境科学
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化学
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DOI
高影响因子
Journal of Materials Chemistry B
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2020
·Vol. 8
·期 7
·1507-1515
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IF 5.344
Kai Xu,Zhenghuan Zhao,Junfeng Zhang,Wei Xue,Haipeng Tong,Heng Liu,Weiguo Zhang
Mn(IV)-Based nanoparticles (NPs) are effective in improving tumor oxygenation (hypoxia) and reducing endogenous hydrogen peroxide and acidity in the tumor region. However, the optimized reduction conditions of conventional Mn(IV)-based NPs are generally reported at pH ≤ 6.5, while the usual pH range of the tumor microenvironment (TME) is 6.5–7.0. The dissatisfactory imaging performance in the weakly acidic environment may limit their further application in tumor diagnosis. In this study, Mn(III) was introduced in a nanoplatform, because it is reduced into Mn(II) in weakly acidic environments. Arg-Gly-Asp (RGD) peptide-decorated bovine serum albumin (BSA) was employed as the stabilizer and scaffold to fabricate Mn(III)- and Mn(IV)-integrated nanocomposites (RGD-BMnNPs) with suitable size, good stability, and excellent biocompatibility. The as-prepared NPs showed clear contrast enhancement at pH 6.5–6.9 in vitro as well as sensitive and rapid T1-weighted imaging performance within the tumor region in a glioblastoma (U87MG) orthotopic model, owing to the intrinsic disproportionation reaction of Mn(III) in the weakly acidic environment. In addition, these NPs could be used for efficient siRNA delivery. They showed superior advantages in this process, including increased tumour uptake, improved tumor accumulation and enhanced therapeutic effects with the modulation of the TME. These novel albumin-stabilized manganese-based NPs combined with efficient drug delivery capacity hold great potential to serve as intelligent theranostic agents for further clinical translation.
研究领域:
生物医学工程
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纳米技术
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癌症研究
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神经科学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Zhimin Gong,Gaobo Wang,Huanhuan Shi,Shuai Shao,Mengjie Wang,Kun Lu,Shixiang Gao
Catalyzed oxidative coupling reactions mediated by enzyme have been proposed as an effective remediation strategy to remove micropollutants, however, little is known about how the Mn(II) redox cycling affects the horseradish peroxidase (HRP)-mediated reactions in wastewater treatment . Here, we explored the removal of two pharmaceuticals and personal care products (PPCPs), methylparaben (MeP) and acetaminophen (AAP), in HRP-mediated reaction system with dissolved Mn (II). It was found that the conversion rate of AAP was about 284 times higher than that of MeP, and Mn (II) significantly inhibited HRP-catalyzed MeP removal but had little influence on that of AAP. X-ray photoelectron spectroscopy (XPS) and theoretical calculations demonstrated that HRP converted Mn(II) into Mn(III), and then generated MnO 2 colloid, which inhibited the removal of the substrates. Moreover, the results of theoretical calculations also showed that the binding energy between HRP and Mn was 27.68 kcal/mol, which was higher than that of MeP (25.24 kcal/mol) and lower than that of AAP (30.19 kcal/mol). Therefore, when MeP and Mn (II) coexisted in the reaction system, HRP preferentially reacted with Mn(II), which explained the different impacts of Mn (II) on the removal of MeP and AAP. Additionally, Mn (II) significantly altered the product distribution by decreasing the amount of polymerization products. Overall, our work here revealed the roles of Mn (II) in the removal of MeP and AAP mediated by HRP, having strong implications for an accurate assessment of the influence of Mn(II) redox cycling on the removal of PPCPs in wastewater treatment.
研究领域:
环境科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2026
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IF 21.1
Yaxiong Zeng,Jie Yu,Beimeng Qi,Fang Tao,Xiaotian Yang,Yulin Wang,Xiaoguang Duan,Hailu Fu
Regulating the microenvironment of single-atom catalysts (SACs) is critical for steering ozone (O 3 ) activation toward selective on-demand reactive species generation. While first-shell coordination engineering modulates the center metal activity, it often disrupts the robust Mn-N 4 symmetry and thus compromises structural stability. Here, we developed atomically dispersed Mn-N 4 -S sites (S-MnN 4 ) that feature sulfur doping in the second coordination shell for catalytic ozonation and water pollutant degradation. Second-shell sulfur incorporation subtly elevated the d -band center and increased the spin state of Mn from low to intermediate, enhancing O 3 adsorption, dissociation and the preferred generation of high-valent Mn(IV)=O species. Consequently, S-MnN 4 achieved a 2.7-fold higher ozone utilization efficiency and double the turnover frequency versus pristine MnN 4 which catalyzed O 3 to primarily yield singlet oxygen. A continuous-flow system using a S-MnN 4 -packed column reactor demonstrated efficient chemical oxygen demand removal and exceptional durability over 170 h for the treatment of real-world wastewater. This work highlights second-shell coordination engineering as a feasible approach to overcome SAC activity-stability trade-off, advancing rational SAC design toward a sustainable environmental remediation.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Junlei Zhang,Wei Zhao,Shanshan Wu,Renli Yin,Mingshan Zhu
Advanced oxidation processes (AOPs) based on heterogeneous catalytic activated peroxymonosulfate (PMS) have been becoming alternatives to conventional wastewater treatment technologies to directly degrade chemical contaminants. To build dual/multi redox cycles of different metal ions may be an effective means for better PMS activation. Herein, this study designed Mn 3 O 4 /CuBi 2 O 4 with dual redox cycles of Mn(III)/Mn(IV) and Cu(I)/Cu(II) to activate PMS for efficiently decomposing and mineralizing diclofenac sodium (DCF). Under optimal reaction conditions, DCF (50 mg/L) was degraded totally within 10 min, and TOC removal rate reached up to 74.3%. The possible mechanism of PMS activation by Mn 3 O 4 /CuBi 2 O 4 was proposed, wherein dual redox cycles of Mn(III)/Mn(IV) and Cu(I)/Cu(II) on Mn 3 O 4 /CuBi 2 O 4 effectively facilitated PMS activation to generate · O 2 − , 1 O 2 , SO 4 · − and · OH, which was responsible for DCF degradation. Moreover, combined with degraded products detected by high resolution liquid chromatography coupled to mass spectrometry and corresponding toxic assessment results, the possible degradation pathways of DCF were proposed and the relative toxicity of degraded products was evaluated. This work may be useful for developing stronger heterogeneous activators of PMS to construct more efficient AOPs for purifying wastewater.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
CHEMOSPHERE
·
2023
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IF 8.8
Zizhang Guo,Yan Kang,Haiming Wu,Mei Li,Zhen Hu,Jian Zhang
Polycyclic aromatic hydrocarbon (PAHs) are persistent organic pollutants and pose high risk in aquatic environment. The utilization of biochar is a strategy for PAHs-contaminated remediation but is challenging due to the adsorption saturation and reoccurrence of PAHs desorbed back into water. In this study, iron (Fe) and manganese (Mn) were provided as electron acceptors for biochar modification to enhance anaerobic biodegradation of phenanthrene (Phe). Results revealed that, the Mn(Ⅳ) and Fe(Ⅲ) modification improved the removal of Phe by 24.2% and 31.4% than that of biochar, respectively. Additionally, nitrate removal was improved by 19.5% with Fe(Ⅲ) amendment. The Mn-and Fe-biochar decreased Phe contents by 8.7% and 17.4% in sediment, 10.3% and 13.8% in biochar than that of biochar. Much higher DOC contents were observed with Mn- and Fe-biochar, which provided bioavailable carbon source for microbes and contributed to microbial degradation of Phe. The greater degree of humification , higher proportions of humic and fulvic acid like components in metallic biochar participated in electron transport and further enhancing the degradation of PAHs. Microbial analysis proved the high abundance of Phe-degrading bacteria (e.g. PAH-RHD α , Flavobacterium and Vibrio ), nitrogen removal microbes (e.g. amoA , nxrA , and nir ), Fe and Mn bioreduction or oxidation (e. g. Bacillus , Thermomonas , Deferribacter ) with metallic biochar. Based on the results, the Fe and Mn modification, especially Fe-modified biochar provided well performance for PAHs removal in aquatic sediment.
研究领域:
环境科学
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生物修复
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水生生态学
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微生物学
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产品关联
DOI
PubMed
高影响因子
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