ENVIRONMENTAL POLLUTION
·
2022
·
IF 9.988
Yuebei Yang,Yaozhong Wang,Xiaofei Li,Chao Xue,Zhi Dang,Lijuan Zhang,Xiaoyun Yi
The heavy-metal adsorbent ε-MnO 2 was produced through a simple, one-step oxidation-reduction reaction at three different synthesis temperatures (25 °C, 50 °C and 75 °C) and their morphology and chemical-physical properties were compared. Of the three materials, MnO 2 -25 had the largest specific surface area and the highest surface hydroxyl concentration. Its optimal performance was demonstrated by batch adsorption experiments with Pb 2+ , Cd 2+ and Cu 2+ . Of the three metals, Pb 2+ was adsorbed best (339.15 mg/g), followed by Cd 2+ (107.50 mg/g) and Cu 2+ (86.30 mg/g). When all three metals were present, Pb 2+ was still absorbed best but now more Cu 2+ was adsorbed than Cd 2+ . In order to explore the mechanism for the inconsistent adsorption order of Cd 2+ and Cu 2+ in single and competitive adsorption, we combined experimental data with density functional theory (DFT) calculations to elucidate the distinct adsorption nature of MnO 2 -25 towards these three metals. This revealed that the adsorption affinity of the (100) facet was superior to (001), and since the surface complexes were also more stable on (100), this facet was most likely determining the adsorption order for the single metals. When the metals were present in combination, Pb 2+ preferentially occupied the active adsorption sites of (100), forcing Cu 2+ to be adsorbed on the (001) facet where Cd 2+ was only poorly bound. Thus, the adsorption behavior was affected by MnO 2 -25 surface chemistry at a molecular scale. This study provides an in-depth understanding of the adsorption mechanisms of the heavy metals on this adsorbent and offers theoretical guidance for production of adsorbent with improved removal efficiency.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yingying Fang,Wenbo Zhou,Yihuan Cheng,Yuge Zhang,Tingting Yu,Shaoxian Song
The high-value utilization of steel pickling waste liquid (SPWL) is an important direction in the resourceful utilization of hazardous waste. In this study, nano-Fe 3 O 4 prepared from SPWL (S-Fe 3 O 4 ) was hydrothermally compounded with MnO 2 as Fe 3 O 4 -MnO 2 (SFM), which were compared with Fe 3 O 4 -MnO 2 (CFM) prepared by chemical reagents. The synthetic materials were evaluated by SEM, VSM, BET, XRD, and zeta potential, the results show that the spherical S-Fe 3 O 4 was encapsulated by spiny spherical shell-like MnO 2 , and the SFM has a high saturation magnetization and specific surface area (159.91 m 2 /g). The adsorption experiments demonstrated that the adsorption effect of SFM on Pb 2+ is highly similar to that of CFM. The maximal adsorption capacity of SFM reached 129.74 mg/g under ideal composite ratio and pH conditions, and the adsorption process was unaffected by competing heavy metal ions coexisting in the environment. Moreover, the high saturation magnetization strength of the SFM makes it simple to separate materials under a magnetic field. The pseudo-second-order kinetics and Langmuir isotherm models provided a good description of the Pb 2+ adsorption on SFM. XPS and FTIR analysis provided evidence that the adsorbent surface has a high concentration of -OH functional groups, and that O atoms serve as Pb 2+ binding sites, suggesting that ion exchange occurs during the SFM adsorption process. In this paper, we developed a cheap SFM with high adsorption performance and provided a novel approach to the high-value application of SPWL.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Jinmei Xu,Senqi Xu,Shangqing Tang,Luyao Wang,Kui Wan,Chuqiao Wang
The widespread use and release of 2,4,6-Trichlorophenol (TCP) poses a significant risk to water bodies and ecosystems. Designing efficient and stable catalysts for photocatalytic degradation of TCP remains a great challenge. In this paper, a Z-scheme α-MnO 2 /Bi 2 S 3 (Mn/Bi) composite enriched with oxygen (O Vs ) and sulfur (S Vs ) vacancies is designed for photocatalytic degradation of TCP. 60-Mn/Bi achieved 88 % degradation efficiency for 20 mg/L TCP solution. The reaction rate ( k ) of 60-Mn/Bi is 6.46 and 4.41 times higher than that of α-MnO 2 and Bi 2 S 3 , respectively. The catalyst exhibited high catalytic activity in a wide pH range and high resistance to anion. In addition, the cycling performance of 60-Mn/Bi is relatively stable, and the ion leaching rate is low. The Z-scheme mechanism is confirmed by characterization and DFT, which effectively retained the strong redox capacity. The abundant vacancy structure enhances the adsorption of TCP and promotes the migration of photogenerated carriers. In addition, the rod-shaped Bi 2 S 3 provides a carrier for α-MnO 2 nanoparticles, which effectively alleviates agglomeration and thus exposes more active sites. Three possible degradation pathways were explored by LC-MS and DFT. This study provides a facile method and guidance for the preparation of Z-scheme catalysts to improve photocatalytic degradation performance.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Qi Dong,Jun Wang,Xiaoguang Duan,Xiaoyao Tan,Shaomin Liu,Shaobin Wang
A novel hybrid architecture of 3D MnO 2 nanosheet/N-doped graphene aerogel (S-MnO 2 /NGA) was controllably fabricated by a facile hydrothermal process and applied in peroxymonosulfate (PMS) activation for catalytic degradation. The catalytic efficiency of S-MnO 2 /NGA is notably higher than MnO 2 nanotube/NGA (T-MnO 2 /NGA), NGA and MnO 2 samples as well as some other conventional catalysts. The reaction rate constant (k) and activation energy for ibuprofen oxidation on S-MnO 2 /NGA are 0.149 min −1 and 10.2 kJ/mol, respectively. The intimate interactions between 2D MnO 2 nanosheet and 3D porous N-doped graphene aerogel are beneficial for synergistically enhancing the charge transfer and shortening the diffusion pathway of pollutants to promote mass transport, thus exerting an astonishing enhancement in the catalytic activities. Electron paramagnetic resonance (EPR) spectra and quenching tests verified that both hydroxyl ( OH) and sulfate radicals (SO 4 − ) were generated, while SO 4 − is the major reactive species responsible for ibuprofen oxidation. The positively linear correlation between the k values and pore volume of S-MnO 2 /NGA indicates that the 3D interconnected framework provides shorter pathways and more active sites for pollutant diffusion and oxidation. This approach contributes to a better understanding of the structure-activity relationship of 3D graphene-based aerogels in advanced oxidation processes (AOPs).
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Fen Qiao,Wenjie Liu,Shuihua Yu,Qiaoling Zhang,Guodong Li,Huaqiang Chu
Mn 2 O 3 is and has received widespread attention in fields such as catalysis and energy storage. However, its poor conductivity limits its application as an electrode material for supercapacitors. Here, flower-like spheroidal δ-MnO 2 /Mn 2 O 3 composites composed of two-dimensional (2D) hierarchical nanosheets were prepared by the template method and a simple hydrothermal process. The growth process and electrochemical properties of δ-MnO 2 /Mn 2 O 3 composites were investigated by adjusting the concentration of KMnO 4 in the hydrothermal process. Since the introduction of δ-MnO 2 brings more pseudocapacitance to the composite, the synergistic effect between MnO 2 and Mn 2 O 3 reduces the interfacial resistance, and the unique nanosheet structure increases its specific surface area, which alleviates the volume expansion during the cycling, the δ-MnO 2 /Mn 2 O 3 composite electrode exhibits high specific capacitance (182 F g −1 at 0.5 A g −1 ), fast rate performance (74.2% capacitance retention at 5 A g −1 ), and excellent cyclic stability (90.1% capacitance retention after 5000 cycles at 5 A g −1 ). Symmetric supercapacitors assembled with δ-MnO 2 /Mn 2 O 3 electrodes also exhibit a high energy density of 9.1 Wh kg −1 . δ-MnO 2 /Mn 2 O 3 composites have greater application prospects in energy storage, and are expected to achieve further applications in lithium/sodium ion batteries, zinc ion batteries and other fields.
研究领域:
材料科学
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能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Xiaowen Chen,Zihan Xu,Sai Guo,Bo Sun,Qijian Li,Qingkun Meng,Fuxiang Wei,Jiqiu Qi,Yanwei Sui,Peng Cao
Improving electrical conductivity and increasing the active site are important directions for improving the technology of manganese-based cathode materials for zinc ion batteries (ZIBs). In this paper, cobalt-doped and oxygen-vacancy coupled MnO2 nanorods (Vo-CMO) were prepared by defect engineering and an ion doping strategy as cathode materials for rechargeable ZIBs. Oxygen vacancies can increase the defect density of the material and provide more migration paths for zinc ions, thereby increasing the electrochemical activity and improving the specific capacity. The introduction of cobalt can adjust the electronic structure of manganese oxide, change the Fermi level of the material, and promote the generation and transmission of charge carriers, thereby increasing the charge transfer rate and increasing the conductivity of the material. The synergistic effect among them can improve the diffusion kinetics of zinc ions, thereby increasing the capacity and cycle stability of the material. The Vo-CMO has better Zn2+ storage capacity of 295.6 mAh·g–1 at 0.1 A·g–1. The reaction mechanism of Vo-CMO material was H+/Zn2+ coinsertion through galvanostatic current intermittent titration (GITT) and ex situ experiments. In addition, the Vo-CMO material assembled the flexible quasi-solid ZIB. The synergistic effect of cobalt doping and oxygen vacancy can provide a new way to develop water-based ZIBs.
研究领域:
材料科学
·
电化学
·
储能
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纳米材料
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电池技术
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 3
·1728-1737
·
IF 4.036
Zhuo-Rui Li,Xiao-Hui Zhang,Yue-Yue Du,Guo-Zhi Han
In this paper, using hollow silica microspheres as carriers, we developed a facile one-pot method for the preparation of hollow SiO2@MnO2 composite microparticles. Under a certain proportion of hollow silica microspheres and manganese salt, a novel kind of hollow urchin-like SiO2@γ-MnO2 microparticles was obtained. The structure and morphology of the composite microparticles were characterized by XRD, SEM and TEM. On this basis, using rhodamine B and methyl orange as model molecules, the oxidative degradation ability of the hollow SiO2@γ-MnO2 microparticles for organic dyes in water was investigated through UV-vis analysis technology. The urchin-like SiO2@γ-MnO2 microparticles showed excellent performance for the rapid oxidative degradation of organic dyes under acidic conditions. This study indicated that γ-MnO2 loaded on hollow materials can be used as an efficient tool for treating organic dye wastewater, and shows broad application prospects for solving environmental problems in the related industry.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Qing Luo,Chenyue Yan,Ruoteng Ma,Lei Dai,Wenjun Shu,Anum Asghar,Zhigang Jia,Xulong Zhu,Shun Yu
The development of multifunctional hydrogels, especially hydrogels with antibacterial and antioxidant properties, plays a crucial role in the effective healing of diabetic wounds. This work proposed a novel composite hydrogel with the oxidized gellan gum (O-GG) and hyaluronic acid (HA) as the hydrogel matrix, and the crosslinking was realized via the Ca 2+ . ε-polylysine/MnO 2 nanozymes (EM) offered antioxidant and antibacterial properties to the corresponding composite hydrogels. The results verified that the O-GG/HA@EM hydrogel exhibited excellent cytocompatibility and injectability. The CCK-8 data indicated that the proliferation rate of mouse fibroblasts reached 314.58 % after three days of coculture with the hydrogel. The hydrogel effectively alleviated oxidative stress and hypoxic microenvironments in wounds, inhibited bacterial infection, and promoted angiogenesis, thereby significantly accelerating the healing process of diabetic wounds. Data from a mouse diabetic wound model revealed that the wound closure rate in the sample group reached 92.4 % after 14 days. This composite hydrogel provides a novel and effective solution for the treatment of chronic diabetic wounds.
研究领域:
生物材料学
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医学
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纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Wei Xu,Wei Yang,Yin Dai,Jianwen Fei,Chenxi Zhang,Yani Zheng,Wanying Zhu,Jun Zhang,Junli Hong,Xuemin Zhou
Ratiometric fluorescence sensors with quantum dots (QDs) as signal reporters have been widely used in biomarkers testing. However, there are few reports on the construction of a ratio fluorescence sensor based on the dual action of enzyme reaction and QDs. In this study, a “two-in-one” multifunctional catalytic QDs (BSA-MnO2 QDs) developed by hydrothermal method displayed excellent fluorescent properties and high oxidase-like activity. Its optimal quantum yield and Michaelis–Menten kinetics constants Km were 10.7% and 0.072 mM, respectively. In the presence of an enzyme substrate, the ratiometric signal can be generated indirectly by BSA-MnO2 QDs catalyzing, which was more conducive to the construction of a ratio fluorescence biosensor and made the experiment result more accurate. Based on these advantages, an acid phosphatase (ACP) ratiometric fluorescence biosensor was designed. In the absence of ACP, o-phenylenediamine (OPD) was catalyzed to produce 2,3-diaminophenothiazine (DAP) (the oxidized fluorescent product of OPD) that has an inner-filter effect with BSA-MnO2 QDs. Conversely, in the presence of ACP, l-ascorbic acid-2-phosphate was dephosphorylated to produce ascorbic acid, which inhibited the oxidase-like activity of BSA-MnO2 QDs and prevented the catalytic oxidation of OPD to DAP. The method can achieve the assay of ACP with a detection limit of 0.038 mU/mL. In addition, this effect can be achieved when other natural enzymes catalyze substrates to produce reducing substances. In this study, a universal ratio fluorescence probe (BSA-MnO2 QDs) was discovered and prepared for the first time, which has wide application prospects.
研究领域:
生物化学
·
医学检测
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2023
·Vol. 15
·期 18
·8255-8269
·
IF 6.7
Huanhuan Wang,Qi Qu,Jiangshan Gao,Yan He
Herein, Fe3O4@MnO2@Ni–Co/C composites derived from PBAs were successfully fabricated. Firstly, Ni–Co Prussian blue analogues (Ni–Co PBAs) were used as precursors to derive a carbon layer on their surface by annealing treatment and subsequently translated into MnO2@Ni–Co/C nanocubes after hydrothermal reactions. Fe3O4@MnO2@Ni–Co/C composites were finally obtained after depositing Fe3O4 nanoparticles through the annealing process. Their electromagnetic wave (EMW) absorption performance apparently enhanced, thanks to the excellent impedance matching and strong attenuation derived from the synergy between the dielectric loss and the magnetic loss. In particular, the minimum reflection loss (RLmin) of Fe3O4@MnO2@Ni–Co/C reached −41.2 dB with a thickness of 4.0 mm and the effective absorption bandwidth (EAB) reached 7.1 GHz with a thickness of 2.0 mm. Therefore, the results could be significant for synthesizing EMW absorbers with excellent performance, a broad bandwidth, strong absorption, thin thickness and light weight.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Yiping Liu,Wuxiang Zhang,Wanhe Li,Jie Xiong,Zuqiang Huang,Tao Gan,Huayu Hu,Yuben Qin,Yanjuan Zhang
Ozone (O 3 ) demulsification shows great potential in emulsion wastewater treatment due to its strong oxidative properties. However, the low mass transfer efficiency and oxidation selectivity of O 3 cannot be ignored. Herein, a MnO 2 /porous spontaneously polarized ceramic (MnO 2 /PSPC) composite with strong interfacial interactions and self-powered electric field was prepared for heterogeneous catalytic ozonation (HCO) to achieve efficient demulsification. Excellent remanent polarization (0.00858 μC/cm 2 ) together with systematic electrochemical characterizations of MnO 2 /PSPC demonstrated its significant charge transfer capability, which is essential for the subsequent reduction of Mn 4+ in the HCO demulsification process. O 3 - MnO 2 /PSPC exhibited excellent demulsification performance with 99 % demulsification rate of cetyltrimethylammonium bromide-stabilized emulsion within 30 min, outperforming O 3 (130 min), O 3 -MnO 2 (60 min), and O 3 -PSPC (90 min). O 3 -MnO 2 /PSPC showed effective demulsification of non-/anionic surfactant stabilized emulsions and excellent stability after 5 cycles. Density functional theory calculations together with characterizations illustrate that potential difference-induced rapid electron transfer and water flow-induced self-powered electric field were the fundamental motivation for the fast Mn 3+ /Mn 4+ cycle and O 3 adsorption/decomposition to generate reactive oxygen species (ROS). Notably, the oxidation of surfactants by ROS led to the coalescence of the oil droplets. This study provides an efficient, sustainable, and energy-efficient method to improve the O 3 demulsification performance.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Chun Huang,Yulan Wang,Miao Gong,Wei Wang,Yang Mu,Zhen-Hu Hu
The discharging of Rhodamine B (RhB) from wastewater has caused huge environment pollution. Peroxymonosulfate (PMS) oxidation is an effective way to remove it from wastewater. However, finding an environmentally friendly metal to activate PMS is a key step for the oxidation process. In this study, nanorod α-MnO 2 loaded palygorskite (α-MnO 2 /Pal) was fabricated by a simple hydrothermal method. The analysis of field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) confirmed the loading of α-MnO 2 on the surface of Pal and characterized the surface of the composite. The surface area of α-MnO 2 /Pal composite was 159.13 m 2 /g, which was much higher than that of Pal and α-MnO 2 . The Pal, α-MnO 2 , Mn 2+ , and α-MnO 2 /Pal were used to activate PMS for RhB degradation. Nearly 100% RhB degradation was obtained in α-MnO 2 /Pal + PMS system in 180 min and in α-MnO 2 + PMS system in 300 min, while only 50% degradation was obtained in Pal + PMS system and 71.4% degradation in Mn 2+ + PMS system in 300 min. The degradation fitted the pseudo-first-order reaction kinetics well with rate constant of 0.02041 min −1 for α-MnO 2 /Pal + PMS system, 0.01192 min −1 for α-MnO 2 + PMS system, and 0.00435 min −1 for Mn 2+ + PMS system, respectively. The factors affecting RhB degradation were further investigated. The RhB degradation efficiency increased with the increase of α-MnO 2 /Pal dosages, PMS dosages and temperatures. The degradation was inhibited at pH > 5.5, while was favorable at pH < 5.5. The major reactive radicals responsible for RhB degradation classified by radical quenching experiment were O 2 − and 1 O 2 . The possible mechanism was further proposed based on the results. The α-MnO 2 /Pal composite showed nearly 50% mineralization ratio in the presence of PMS and an excellent reusability. The results from this study revealed that α-MnO 2 /Pal composite is an effective catalyst to activate PMS for RhB degradation.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）