MOLECULES
·
2024
·Vol. 29
·期 3
·663
·
IF 4.2
Zhenrui Li,Yujun Li,Shijie Li,Jianfeng Ma,Qianli Ma,Zhihui Wang,Jiajun Wang,Keying Long,Xing’e Liu
Novel bamboo activated carbon (BAC) catalysts decorated with manganese oxides (MnOx) were prepared with varying MnOxcontents through a facile one-step redox reaction. Due to the physical anchoring effect of the natural macropore structure for catalyst active components, homogeneous MnOxnanoparticles (NPs), and high specific surface area over catalyst surface, the BAC@MnOx-N (N = 1, 2, 3, 4, 5) catalyst shows encouraging adsorption and catalytic oxidation for indoor formaldehyde (HCHO) removal at room temperature. Dynamic adsorption and catalytic activity experiments were conducted. The higher Smicro(733 m2/g) and Vmicro/Vt(82.6%) of the BAC@MnOx-4 catalyst could facilitate its excellent saturated and breakthrough adsorption capacity (5.24 ± 0.42 mg/g, 2.43 ± 0.22 mg/g). The best performer against 2 ppm HCHO is BAC@MnOx-4 catalyst, exhibiting a maximum HCHO removal efficiency of 97% for 17 h without any deactivation as RH = 0, which is higher than those of other MnOx-based catalysts. The average oxidation state and in situ DRIFTS analysis reveal that abundant oxygen vacancies on the BAC@MnOx-4 catalyst could be identified as surface-active sites of decomposing HCHO into the intermediate species (dioxymethylene and formate). This study provides a potential approach to deposit MnOxnanoparticles onto the BAC surface, and this hybrid BAC@MnOxmaterial is promising for indoor HCHO removal at room temperature.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Shouhao Tong,Hongyan Wei,Junming Zhou,Yixuan Yang,Runliang Zhu,Qingze Chen,Xiande Xie,Qing Hu,Michael F. Hochella Jr.,Jing Liu
Heterogeneous crystallization of manganese (oxyhydr)oxides (MnOx) on iron (oxyhydr)oxides (FeOx) is crucial for the biogeochemical cycling of Mn, yet atomic-level insights into this process are important but relatively limited. Herein, we revealed the distinct adsorption, oxidation, and crystallization mechanisms of Mn on hematite (Hem), ferrihydrite (Fhy), and goethite (Gth). Gth exhibited highest ability in Mn(II) removal and oxidation, followed by Hem and Fhy. Manganite and hausmannite were the main MnOx products with distinct proportions, and morphologies cross the systems. MnOx growth mechanisms involve surface-induced nucleation, crystallization by particle attachment (CPA), and self-catalyzed growth. On Fhy, self-catalyzed growth was dominant; for Gth, surface-induced nucleation was prevalent, supplemented by CPA; and Hem combined all three mechanisms. These distinct mechanisms led to nanoparticles primarily of hausmannite on Gth and nanowires of manganite and hausmannite on Hem and Fhy, with those on Hem displaying lower aspect ratios. Differences in MnOx structure and morphology were attributed to Mn(II)-FeOx complexation, FeOx electronic band structure, and crystal structure mismatch between MnOx and FeOx, which respectively influenced the direct and indirect electron transfer and heterogeneous nucleation efficiency. This work advances our understanding of MnOx crystallization on FeOx at the nanoscale, explaining the diverse morphology and structure of MnOx in different environments.
研究领域:
环境科学
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材料科学
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地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2019
·
IF 4.888
Yi Yu,Jian Ji,Kai Li,Haibao Huang,Rajendra P. Shrestha,Nguyen Thi Kim Oanh,Ekbordin Winijkul,Jiguang Deng
MnO nanoparticles supported on coal-based activated carbon (AC) were facilely fabricated via incipient wetness impregnation method by calcination of manganese acetate in nitrogen. The as-prepared catalysts were characterized by N 2 adsorption-desorption, XRD, TEM, and XPS. It is demonstrated that calcination under inert atmosphere can facilely obtain well dispersed MnO nanoparticles on AC, and the particle size, as well as the surface oxygen species of the catalysts strongly depended on the calcination temperature. The AC supported MnO nanoparticles all exhibited high catalytic activity toward ozone decomposition at room temperature, and an optimal one was displayed as the calcination temperature of 700 °C. The smallest particle size of MnO nanoparticles and the most amount of surface oxygen vacancies, were mainly responsible for the highest activity of MnO/AC-700. Moreover, lower loading of Mn was found to be more favorable for stable catalytic performance. This work reported a series of MnO based catalysts for efficient removal of ozone at room temperature for the first time, and may shed new lights on the design of manganese oxides with lower oxidation state for efficient ozone decomposition.
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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Man Qi,Fan Li,Zheng Zhang,Qiao Lai,Yuwen Liu,Jianmin Gu,Liqiu Wang
Aqueous zinc-ion batteries (ZIBs) are receiving a continuously increasing attention for the flexible and wearable electronics, due to their non-toxicity, non-flammability, and low-cost features. The development of high-performance flexible cathodes is of great significance to the development of flexible ZIBs. In this work, the flexible electrode of three-dimensional (3D) interconnected ultrathin MnO 2 nanosheets on carbon cloth (CC@MnO 2 ) coated with Ti 3 C 2 T x MXene (CC@MnO 2 @MXene) is prepared by electrodeposition and dipping methods, in which CC@MnO 2 is put into MXene dispersion for impregnation treatment to make the CC@MnO 2 fibers wrapped with MXene completely. The results show that the coating of MXene improves the conductivity of the composite, and the interface between MXene and MnO 2 provides more active sites. Therefore, CC@MnO 2 @MXene-10 electrode as the cathode of zinc ion battery provides high charge storage performance (517.0 mAh g −1 at 0.1 A g −1 ), excellent cycling stability (80.6 mAh g −1 after 800 cycles at 1 A g −1 ) and excellent energy density (701.3 Wh kg −1 at 133.8 W kg −1 ). Finally, flexible quasi-solid battery based on CC@MnO 2 @MXene composite as cathode was assembled, and the flexible electrodes show potential for application.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CLAYS AND CLAY MINERALS
·
2023
·Vol. 71
·期 1
·106-118
·
IF 2.2
Zhao Fan,Zhang Guangyao,Jiang Yong,Wang Hui,Cao Chi,Qi Yongbo,Wang Qingyun,Zhao Huaiyan
The formation of manganese (Mn) oxides is influenced by environmental conditions and, in some red soils, Mn oxides occur as coatings on the surface of kaolinite particles in the form of colloidal films or fine particles. The present study aimed to explore the types of formation mechanisms of Mn oxide minerals on the surface of kaolinite. Mn oxide minerals synthesized by reducing the Mn in KMnO 4 with a divalent Mn salt (MnSO 4 ) were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of various initial molar ratios of Mn 2+ /Mn 7+ (R = 1:0.67, 1:1, 1:2, and 1:4), cationic species (Na + or Mg 2+ ), synthesis temperatures (30, 60, and 110°C), and amount of added kaolinite (0.25, 0.5, 1.0, 2.0, and 5.0 g) on the formation of Mn oxides were studied. The results showed that Mn oxide mineral types were affected by the initial R value and the background cation. With decreases in the initial R value, the synthesized minerals transformed from cryptomelane to birnessite. The relative mass ratios of kaolinite to Mn oxide were calculated as 1:0.92, 1:0.63, 1:1.15, and 1:1.63. The sodium cation (Na + ) had a greater role than Mg 2+ in promoting the dissolution–recrystallization of birnessite to cryptomelane. The synthesis temperature had no effect on mineral types, but Mn content increased as temperature increased. When the amount of added kaolinite was increased from 0.25 to 5.0 g, Mn oxide minerals formed gradually and transformed from birnessite to cryptomelane. This work revealed a possible formation process and reaction mechanism on the surface of kaolinite particles in some red soils.
研究领域:
土壤学
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矿物学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Yuanhao Liu,Yingying Mei,Wen Xu,Minghui Zhang,Junwei Hou,Yanfeng Dong
Aqueous zinc ion batteries (ZIBs) are regarded as a promising battery mainly due to their high safety and environmental friendliness, but suffer from low capacity and energy density . Herein, a pre-intercalated manganese oxide (Na 0.55 Mn 2 O 4 ·1.5 H 2 O)/MXene hybrid (NMO/MXene) is successfully proposed for high-performance ZIBs , in which synergistic effect between MXene and NMO greatly improves the structural stability of NMO and facilitates fast charge transfer and ion diffusion kinetics. Therefore, the resulting NMO/MXene cathodes deliver high-rate capacity of 180 mAh g −1 at 10 C (3.08 A g −1 ) and long cycling life over 2500 times at 5 C, outperforming most reported Mn-base cathodes. The MXene-mediated strategy for advanced Mn-based cathodes developed here paves a new way to construct high-performance Zn-MnO 2 batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qiang Ma,Fan Li,Xianglong Zhang,Bowen Yang,Yingjie Zhang,Qingyuan Wang,Qihong Wu,Jin Huang,Jiming Hao
With the rapid development of ore refining, coal power plants, and mining, aqueous thallium pollution in natural waters has been reported over the past few decades. However, few thallium control technologies have been put into practice. In this study, a modified MOF adsorbent, MnO 2 @HKUST-1(MOH), was fabricated. Its chemical component shift, thermal stability, and microstructure changes during thallium adsorption were analyzed using TGA, XRD, XPS, and TEM-EDS techniques. The results showed a promising Tl + removal rate of over 90 %, and an adsorption capacity of 178.8 mg/g was obtained at a pH of 5 and a temperature of 293 K. The dynamic behavior of Tl + adsorption on MOH was simulated using power rate law expression (PRL), pseudo-first-order model (PFO), and pseudo-second-order model (PSO), which revealed a superior selection of Tl + among other competing heavy metal ions (Cr 3+ , Fe 3+ , Ca 2+ , Zn 2+ , and Cu 2+ ). The Tl + removal mechanism was further studied, which was mainly forced by surface adsorption/desorption. Based on its efficient Tl + removal rate, high adsorption capacity, promising regeneration property, and economical price, the MOH adsorbent has the potential to be a feasible option for smelting, ore refining, packaging, and testing wastewater treatment.
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
PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS
·
2024
·
IF 3.2
Wenwei Tang,Zuxun Huang,Yunying Liu,Xinping Zeng
The microbial manganese removal process is believed to consist of the catalytic oxidation of Mn(II) by manganese oxidase. In this study, the multicopper oxidase CopA was purified and exhibited high manganese oxidation activity in vitro, and it was found that Cu(II) can significantly enhance its manganese oxidation activity. Gene site-directed mutagenesis was used to mutate four conserved copper binding sites of CopA to obtain four mutant strains. The manganese removal efficiencies of the four strains were determined, and it was found that H120 is the catalytically active site of CopA. The loss of Cu(II) and the mutation of the conserved copper binding site H120 resulted in the loss of ethoxyformyl and quinone modifications, a reduction in the number of modifications, and a change in the position of modifications, eventually causing a decrease in protein activity from 85.87% to 70.1%. These results reveal that Cu(II) and H120 play an indispensable role in manganese oxidation by the multicopper oxidase CopA. X-ray photoelectron spectroscopy (XPS) analysis indicates that biogenic manganese oxides produced by strains and by CopA were both composed of MnO 2 and Mn 3 O 4 and that the average valence of Mn was 3.2.
研究领域:
微生物学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Gongting Wang,Zedong Teng,Ziyi Wei,Xin Zhao,Wenqing Luo,Yuxin Cheng,Yali Guo,Xiaonan Ji,Wei Hu,Min Li
The serious contamination of cadmium (Cd) in sediments has become an urgent environmental problem. Quinones mediated dissimilatory iron and manganese reduction widely occurs in sediments, this process may enhance Cd immobilization by promoting production of secondary minerals. Nevertheless, the enhancing effect of Cd immobilization is still poorly understood. Here, 9,10-anthraquinone-2,6-disulfonic acid (AQDS) was used to facilitate the microbial reduction of iron and manganese oxides by Geobacter metallireducens GS-15, and its effects on Cd species was investigated. Compared to goethite (FeOOH), microorganisms preferentially reduced birnessite (MnO 2 ) due to more dramatic interfacial electron transfer between birnessite and AQDS. AQDS thus significantly enhanced microbial reduction of iron and manganese coexisted minerals as well as Cd 2+ immobilization. After 80 days, an impressive 83% of reducible-Cd appeared in the FeOOH–MnO 2 -AQDS group, demonstrating the most effective Cd immobilization. Furthermore, XANES results suggested that AQDS promoted the increase of vivianite-Cd in secondary minerals in MnO 2 -AQDS and FeOOH–MnO 2 -AQDS groups. Based on the structural equation model, HCl-extracted Fe(II) indirectly affected the increase of reducible-Cd mainly through vivianite-Cd. The AQDS enhancement on microbial reduction of iron and manganese oxides promotes the recrystallization of secondary minerals and the immobilization of Cd, offering a promising strategy for the remediation of Cd-contaminated sediments.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Qiang Zheng,Hong Liang,Ran He,Youli Yang,Kaibin Zhang
Mesoporous MnO x -Y and LnO x /MnO x ozone decomposition catalysts were prepared by calcination of Mn-BTC (BTC = 1,3,5-benzentricarboxylate) and doping of lanthanide elements (Ln = La, Ce, Sm, Eu, Er). Compared to MnO x -Y catalysts, the LnO x /MnO x catalysts showed higher ozone catalytic activity, the mutual conversion between Ln n+ and Mn n+ was helpful to improve ozone decomposition. The CeO x /MnO x catalyst showed the highest catalytic that showed 93% conversion of 40 ppm O 3 in the relative humidity (RH) = 65% after 360 min, which was attributed to the largest specific surface area, more oxygen vacancies , Mn 3+ and O ads . In addition, the CeO x /MnO x catalyst was loaded into the non-woven fabric to obtain CeO x /MnO x -NWF catalyst, which showed a highly efficient and stable ozone conversion under the RH range from less than 5%–85%. This work will promote the practical application of Mn-BTC derived catalysts.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Xueying Gao,Weijie Fu,Yanfei Sun,Shiyu Wang,Zishan Hou,Feike Zhang,Xiaoxuan Wang,Shuyun Yao,Jinrui Wang,Yuanming Liu,Shuyuan Li,Kaiqi Nie,Jiangzhou Xie,Zhiyu Yang,Yi-Ming Yan
Manganese dioxide (MnO 2 ) has been recognized for its high theoretical capacitance. Recent advancements highlight the potential of modulating the spin state of Mn to elevate charge transfer kinetics. Nonetheless, the specific relationship between Mn spin distribution and desalination efficacy, alongside the underlying mechanism, remains elusive. This study introduces the novel concept of half-disturbed spin desalination , elucidating its complex mechanism via the strategic induction of oxygen vacancies on the MnO 2 surface. Theoretical analyses reveal that electron transfer from the O p y (up) and p z (up) to the Mn d z 2 (up) orbitals alters MnO 2 's spin state from a symmetric low spin to an asymmetric high spin configuration . This transition disrupts spin up symmetry, bolstering dynamic processes and diminishing the ion diffusion energy barrier. Consequently, oxygen vacancy-enriched MnO 2 (V O -MnO 2 ) demonstrates an enhanced specific capacitance of 289 F g −1 at 1 A g −1 . Remarkably, in the hybrid capacitive deionization (HCDI) process, it achieves a superior salt adsorption capacity (SAC) of 56.5 mg g −1 and a salt adsorption rate (SAR) of 2.5 mg g −1 min −1 . This research pioneers the correlation between spin desalination mechanisms and spin state applications, paving the way for novel applications across diverse fields.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2025
·
IF 7.3
Chao Zhang,Xing-Yue Li,Dong-Xing Guan,Jia-Lu Gao,Qiong Yang,Xiao-Lei Chen,Lena Q. Ma
Cadmium (Cd) contamination in paddy soils threatens global food safety. While manganese (Mn)-based materials show promise in reducing soil Cd bioavailability, their efficacy requires further evaluation. Traditional ex situ sampling methods often overlook metal desorption kinetics and rhizosphere biochemical heterogeneity, potentially misinterpreting Mn's regulatory influence on Cd dynamics. This study employed in situ monitoring tools, including diffusive gradients in thin-films (DGT) measurements, DIFS (DGT-induced fluxes in soils) modeling, and high-resolution DGT and planar optode (PO) imaging, to assess the impact of two Mn oxides (MnO 2 and Mn 2 O 3 ) on Cd bioavailability in rice rhizosphere. Application of MnO 2 and Mn 2 O 3 reduced bioavailable Cd by 28.9 % and 15.3 %, respectively, attributed to elevated soil Mn and Fe levels fostering Cd immobilization. DGT-DIFS results revealed that Mn oxide application prolonged Cd replenishment time and reduced its desorption rate from soil solids. PO imaging identified pH heterogeneity in rice rhizosphere, confirming that Mn oxides mediated Cd bioavailability reduction by increasing pH. High-resolution DGT imaging revealed distinct spatial distribution patterns of Cd, Mn, and Fe fluxes, demonstrating Mn's inhibitory effects on Cd bioavailability. These findings highlight the potential of Mn oxides to mitigate Cd uptake by rice, offering a promising strategy for managing Cd-contaminated soils.
研究领域:
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）