Crystals
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2022
·Vol. 12
·期 11
·1600
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IF 2.67
Kun You,Yifei Yuan,Xiuxian Liao,Wenjun Song,Xuedong He,Huile Jin,Shun Wang
Manganese dioxide is regarded as a promising energy functional material due to its open tunnel structure with enormous applications in energy storage and catalysis. In this paper, α-MnO2with a 2 × 2 tunnel structure and β-MnO2with a 1 × 1 tunnel structure were hydrothermally synthesized, which possess characteristic tunnel structures formed by the interconnected unit structure of [MnO6] octahedrons. With regards to their different tunnel dimensions, the specific mechanism of ion intercalation in these two phases and the effect on their performance as aqueous Zn-MnO2battery cathodes are explored and compared. Comprehensive analyses illustrate that both α-MnO2and β-MnO2provide decent capacity in the aqueous battery system, but their intrinsic stability is poor due to the structural instability upon cycling. At the same time, experiments show that α-MnO2has a better rate performance than β-MnO2under larger currents, thus implying that the former has a broader application in this aqueous battery system.Keywords:α-MnO2and β-MnO2nanostructures;aqueous zinc batteries;electrochemical characterization
研究领域:
材料科学
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电化学
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DOI
高影响因子
ACS ES&T Water
·
2022
·
IF 0
Yi Zhou,Xia Li,Xinyu Chen,Jian Lu,Yanbo Zhou
Manganese dioxide (MnO2) is often used to treat pollutants in water owing to its high oxidative activity. Bisulfite (BS) as an activator can promote the degradation efficiency of MnO2. However, the mechanism of different crystalline MnO2 in the presence of BS is still controversial. The oxidation performance of the tunnel type (α-MnO2, β-MnO2) and the two-dimensional lamellar type (δ-MnO2) in the presence of BS was investigated. β-MnO2/BS exhibited the highest oxidative activity under optimal conditions. The bisphenol A (BPA) oxidation kinetic constant of β-MnO2/BS (0.737 min–1) was 6 and 2.3 times higher than that of δ-MnO2/BS and α-MnO2/BS, respectively. The mineralization efficiency of BPA reached 80.05% within 15 min, owing to the high content of Mn(IV) in β-MnO2. BS could rapidly reduce β-MnO2 to produce a high concentration of Mn(III). Soluble Mn(III) directly participates in the BPA oxidation, and the surface Mn(III) can react with the surface adsorbed oxygen molecules (Oad) to generate superoxide radicals (O2•–) to promote the deep mineralization of target contaminants. Moreover, the β-MnO2/BS system can efficiently oxidate various phenolic organic pollutants even in natural water. This research can provide new insights for better understanding of the oxidation process of different crystalline-phase MnO2/BS.
研究领域:
环境科学
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化学
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DOI
MOLECULES
·
2023
·Vol. 28
·期 19
·6879
·
IF 4.6
Tiantian Zhang,Jiacheng Xu,Yan Sun,Shiyu Fang,Zuliang Wu,Erhao Gao,Jiali Zhu,Wei Wang,Shuiliang Yao,Jing Li
Pt-based catalysts exhibit unique catalytic properties in many chemical reactions. In particular, metal–support interactions (MSI) greatly improve catalytic activity. However, the current MSI mechanism between platinum (Pt) and the support is not clear enough. In this paper, the interaction of 1 wt% Pt nanoparticles (NPs) onβ-MnO2in carbon monoxide (CO) oxidation was studied. The Pt onβ-MnO2inhibited CO oxidation below 210 °C but promoted it above 210 °C. A Pt/β-MnO2catalyst contains more Pt4+and less Pt2+. The results of operando DRIFTS-MS show that surface-terminal-type oxygen (M=O) plays an important role in CO oxidation. When the temperature was below 210 °C, Mn=O consumption on Pt/β-MnO2was less thanβ-MnO2due to Pt4+inhibition on CO oxidation. When the temperature was above 210 °C, Pt4+was reduced to Pt2+, and Mn=O consumption due to CO oxidation was greater thanβ-MnO2. The interaction of Pt andβ-MnO2is proposed.Keywords:metal–support interaction;CO oxidation;terminal-type oxygen;bridge-type oxygen;Pt;MnO2
研究领域:
催化化学
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材料科学
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DOI
PubMed
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 4
·775
·
IF 5.3
Hong Su,Jiangping Liu,Yanan Hu,Tianhao Ai,Chenhao Gong,Jichang Lu,Yongming Luo
As a representative sulfur-containing volatile organic compounds (S-VOCs), CH3SH has attracted widespread attention due to its adverse environmental and health risks. The performance of Mn-based catalysts and the effect of their crystal structure on the CH3SH catalytic reaction have yet to be systematically investigated. In this paper, two different crystalline phases of tunneled MnO2(α-MnO2and β-MnO2) with the similar nanorod morphology were used to remove CH3SH, and their physicochemical properties were comprehensively studied using high-resolution transmission electron microscope (HRTEM) and electron paramagnetic resonance (EPR), H2-TPR, O2-TPD, Raman, and X-ray photoelectron spectroscopy (XPS) analysis. For the first time, we report that the specific reaction rate for α-MnO2(0.029 mol g−1h−1) was approximately 4.1 times higher than that of β-MnO2(0.007 mol g−1h−1). The as-synthesized α-MnO2exhibited higher CH3SH catalytic activity towards CH3SH than that of β-MnO2, which can be ascribed to the additional oxygen vacancies, stronger surface oxygen migration ability, and better redox properties from α-MnO2. The oxygen vacancies on the catalyst surface provided the main active sites for the chemisorption of CH3SH, and the subsequent electron transfer led to the decomposition of CH3SH. The lattice oxygen on catalysts could be released during the reaction and thus participated in the further oxidation of sulfur-containing species. CH3SSCH3, S0, SO32−, and SO42−were identified as the main products of CH3SH conversion. This work offers a new understanding of the interface interaction mechanism between Mn-based catalysts and S-VOCs.Keywords:CH3SH decomposition;MnO2;oxygen vacancies;oxygen migration
研究领域:
催化化学
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环境科学
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DOI
PubMed
高影响因子
DESALINATION
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2026
·
IF 9.9
Jia-Li Wu,Lei Xu,Guo-Wu Zhan,Ming-Lai Fu,Baoling Yuan
A bifunctional evaporator for sola evaporation and photocatalysis was developed. • The 3D hydrogel shows broad-spectrum solar absorption and high energy efficiency. • The Z-scheme heterojunction boosts charge separation and phenol degradation. • A detailed degradation mechanism and reaction pathway of phenol are proposed. Solar interfacial evaporation (SIE) has attracted increasing attention in recent years due to its environmental friendliness, high efficiency, and low-carbon-emission characteristics. However, volatile organic compounds (VOCs) are often not effectively removed during the evaporation process, which can lead to secondary contamination of the collected condensate. Integrating SIE with photocatalysis for seawater desalination has therefore emerged as an effective strategy to mitigate the accumulation of VOCs in the condensate during seawater treatment. In this study, manganese (IV) oxide nanomaterials were coated with silver bromide to construct an AgBr/β-MnO 2 heterojunction that suppresses the fast charge annihilation of photoinduced electron–hole pairs and enhances photocatalytic efficiency. The resulting composite was further incorporated into a photothermal hydrogel (AgBr/β-MnO 2 -PH) matrix with excellent photothermal evaporation properties, forming a three-dimensional (3D) photocatalytic evaporation system capable of significantly improving the removal efficiency of VOCs during photothermal evaporation. Under standard solar irradiation (1 sun, 1 kW m −2 ), the porous acrylamide-based hydrogel evaporator achieved an evaporation rate of 3.47 kg m −2 h −1 and a photothermal transformation efficiency of 93.98%. In-situ irradiated XPS reveals light-induced electron enrichment on AgBr accompanied by electron depletion on β-MnO 2 , providing experimental support for a direct Z -scheme interfacial charge-transfer pathway that promotes carrier separation and reactive oxygen species (ROS)-mediated photocatalysis. Consequently, the AgBr/β-MnO 2 -PH system exhibits a removal efficiency exceeding 99% when treating phenol-containing wastewater. Overall, this work demonstrates an effective strategy for coupling SIE with photocatalytic degradation of VOCs. The developed AgBr/β-MnO 2 -PH provides a promising approach for producing freshwater from VOC-contaminated sources and offers new insights into the application of solar energy in seawater desalination and wastewater purification. Download: Download high-res image (337KB) Download: Download full-size image
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2026
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IF 9.6
Muhammad Murad,Zhengqiang Zhao,Kashif Ali,Yanhui Lu,Liwei Lin,Donglei Guo,Ho Seok Park,Huan Pang,Xu Yu
Aqueous zinc-ion batteries (AZIBs) as promising candidates for grid-scale storage are constrained by the poor conductivity and structural instability of manganese dioxide (MnO 2 ) cathodes during cycling. Herein, we report a rationally designed cathode comprising β-MnO 2 nanorods intimately decorated with reduced graphene oxide (β-MnO 2 @rGO) through an in-situ hydrothermal and thermal activation process. The one-dimensional β-MnO 2 nanorods provide shortened diffusion pathways for H + /Zn 2+ ions, while the conformal rGO network establishes a three-dimensional conductive skeleton that enhances electronic transport and buffers volumetric expansion during cycling. X-ray photoelectron spectroscopy (XPS) confirms the formation of robust Mn-O-C interfacial bonds, which facilitate charge transfer and mitigate manganese dissolution. The optimized β-MnO 2 @rGO-30 exhibits a high reversible specific capacity of 387 ± 3.0 mAh g −1 at 0.1 A g −1 and maintains 89 ± 1% capacity retention after 6000 cycles at 1.0 A g −1 . A sequential insertion mechanism, beginning with H + intercalation followed by Zn 2+ storage, with excellent structural reversibility, is elucidated by ex-situ spectroelectrochemical analysis. This work provides a viable strategy for designing high-performance MnO 2 -based cathodes through synergistic nanoengineering and conductive hybridization for advanced AZIBs. This work constructs β-MnO₂@rGO heterostructures with covalent Mn-O-C bonds to overcome poor conductivity and structural instability in AZIB cathodes. The rGO scaffold enhances reaction kinetics, buffers volume change, and suppresses Mn dissolution. The optimized electrode delivers a high reversible specific capacity, excellent capacitance retention and cyclic stability. Download: Download high-res image (146KB) Download: Download full-size image
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DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2022
·
IF 7.34
Lingjie Ke,Jing Liu,Lei Sun,Fei Pan,Xiangjuan Yuan,Dongsheng Xia
In this paper, a series of copper oxide supported manganese dioxide (Cu X Mn T ) composites were prepared by the hydrothermal and deposition precipitation methods. The effects of different hydrothermal temperatures (100 °C–180 °C) and copper doping amounts (1–10 mM) on the structural and physicochemical properties of Cu X Mn T composites were systematically investigated. The BET, SEM , and XRD characterizations revealed that the Cu X Mn T composites exhibited a typical rod-like structure. Besides, with the increscent hydrothermal temperature, the BET specific surface area decreased and the crystal form of the composites changed from α-MnO 2 to β-MnO 2 . The Cu 1 Mn 180 with low specific surface area (3.277 m 2 g −1 ) exhibited the splendid catalytic ozonation activity and the oxalic acid (OA) removal rate reached 87.5% in O 3 /Cu 1 Mn 180 process compared with single ozonation (3.2%). Additionally, it was noteworthy that the excellent catalytic performance of Cu 1 Mn 180 (91.8% of OA removal rate) at pH 3.0 was resulted from the electrostatic adsorption. While, the complexation played a vital role for OA degradation at pH 6.0 and 9.0 with the OA removal efficiencies of 87.5 and 70.3% within 30 min, respectively. Furthermore, Cu 1 Mn 180 could obtain more than 90.9% of OA removal rate during multiple consecutive cycles, representing the satisfactory stability and reusability. Moreover, the multivalent Mn, the structural oxygen species, and Cu species played the key roles for OA degradation in O 3 /Cu 1 Mn 180 process at pH 6.0 via the TEM, ESR, XPS and O 2 -TPD characterizations. Overall, the results presented a promising alternative material for efficient catalytic ozonation application in water.
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
ANALYTICA CHIMICA ACTA
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2021
·
IF 6.558
Meiyan Zhu,Xiaotong Dong,Ming Li,Liangbin Jia,Ye Ma,Minggang Zhao,Hongzhi Cui
Detection of pollutants in seawater faces a great challenge of strong interference, and the facile detection method is lacked. The CoMn 2 O 4 /β-MnO 2 p-n junction oxidase mimetics were successfully prepared for colorimetric detection of hydroquinone in seawater. The catalysis ability was enhanced significantly by the photo-induced p-n junction interface effect. It not only promoted the formation of H 2 O 2 by suppressing the recombination of photon-generated carriers, but also provided the driving force for electron transport . The colorimetric detection of hydroquinone was achieved by fading and exhibited good adaptability in seawater. The obtained good recovery rate (97.23%–101.37%) in seawater makes it an inspiring method for practical application. The photo-induced p-n junction interface effect provides an opportunity for developing the application of colorimetric sensing in seawater detection.
研究领域:
环境科学
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分析化学
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DOI
PubMed
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Jiacheng Xu,Tiantian Zhang,Shiyu Fang,Zuliang Wu,Erhao Gao,Jiali Zhu,Shuiliang Yao,Jing Li,Lianxin Dai,Weihua Liu,Buhe Zhang,Junwei Zhang
The position of the catalyst in a plasma reactor has an important effect on performance of plasma driven catalytic reaction. An operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and mass spectrometry (MS) has been used to investigate CO oxidation on MnO 2 catalyst in in-plasma catalysis (IPC) and post-plasma catalysis (PPC) configurations. It was found that the catalyst in IPC configuration has higher CO conversion and CO 2 selectivity than that in PPC configuration. Operando DRIFTS-MS analysis showed that the IPC configuration generated more reactive oxygen species (M O) on the catalyst surface than the PPC configuration, where M O, M 2+ -O 2 2– , and M + O 2 – are important reactive species promoting CO oxidation to monodentate carbonate that is easy to gasify to gaseous CO 2 . The physical adsorbed O 3 on the catalyst in PPC configuration converts to M 2+ -O 2 2– which combines with CO to form bidentate carbonates that is difficult to gasify to gaseous CO 2 . The mechanisms of CO oxidation on the catalyst in IPC and PPC configurations are discussed.
研究领域:
化学工程
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催化科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）