APPLIED SURFACE SCIENCE
·
2026
·
IF 6.9
Yongxin Liang,Jinlong Liang,Wenhong Lei,Huamin He,Zuqiang Huang,Huayu Hu,Tao Gan,Yanjuan Zhang
Photocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) represents a promising pathway for the valorization of biomass. However, this process still encounters challenges including low conversion efficiency and limited selectivity. To address these issues, a MnO 2 /potassium-doped carbon nitride (MnO 2 /K-CN) heterojunction photocatalyst, featuring abundant oxygen vacancies and intercalation structure, was synthesized for highly efficient and selective photocatalytic oxidation of HMF to DFF. Characterizations reveal that MnO 2 /K-CN with a large specific surface area facilitates the exposure of active sites and the mass transfer of reactants. Concurrently, the S-scheme heterojunction not only broadened the visible-light absorption range but also increased the density of oxygen vacancies in MnO 2 , effectively promoting the separation of photogenerated electron‒hole pairs. MnO 2 /K-CN induced the selective generation of superoxide radicals (•O 2 − ) and singlet oxygen ( 1 O 2 ) while suppressing the formation of hydroxyl radical (•OH), achieving high selectivity toward DFF. MnO 2 /K-CN achieved a HMF conversion of 98.6% and a DFF yield of 94.4%, while maintaining excellent catalytic stability. Theoretical calculations further reveal that MnO 2 /K-CN significantly reduced the energy barrier for the oxidation reaction of HMF, accelerating the oxidation kinetics. This study provides new insights for developing highly efficient and stable photocatalytic systems to achieve high-value-added utilization of biomass resources.
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高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Guochen Ji,Miao Sun,Meizhi Li,Ruofei Hu,Junping Zheng
Aqueous zinc ion batteries (AZIBs) are highly regarded as new generation of energy storage devices because of low cost and environmental friendliness. Particularly, flexible AZIBs with hydrogel electrolytes are suitable candidates for wearable electronics. However, continuous water-induced side reactions, uncontrolled dendrites and trade-off of electrochemical performances with mechanical strength are still obstacles for high-performance AZIBs. To address these issues, we designed a polyanionic hydrogel electrolyte (PAPHE) with sulfonate monomers and polyethylene glycol diacrylate (PEGDA) as crosslinker. Due to the electrostatic interactions between Zn 2+ and sulfonate ions, Zn 2+ can migrate along polyanionic chains. Meanwhile, electronegative oxygen atoms in PEGDA also interact with Zn 2+ and weaken electrostatic interactions. The transfer channels are formed with “wall” of polyanion chains and PEGDA. Moreover, both sulfonate ions and ether bonds on the “wall” can regulate the solvation structure to reduce the activity of water, inhibiting side reactions, corrosion or by-products. Therefore, the PAPHE shows satisfying conductivity of 16.38 mS cm −1 , stable Zn plating/stripping over 1600 h, flexibility and high compressive resistance (0.501 MPa at strain of 50 %). The Zn||PAPHE||MnO 2 cells deliver good specific capacity of 274.5 mAh g −1 and can cycle over 1800 times. The pouch-cell can also work stably under various deformations.
研究领域:
材料科学
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能源存储
·
电化学
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高影响因子
ELECTROCHIMICA ACTA
·
2026
·
IF 5.6
Xiaolei Shi,Zhuannian Liu,Yifei Wang,Benlong Wei
The K-CP/MnO 2 composite was prepared by loading manganese dioxide (MnO 2 ) nanosheets onto potassium hydroxide (KOH) activated carbonized polyaniline (K-CP) via low-temperature hydrothermal reaction. The composite demonstrated high efficiency in removing Pb 2+ and Zn 2+ in the hybrid capacitive deionization (HCDI) technology. K-CP/MnO 2 presents a core-shell structure with conductive K-CP as the core and electrochemically active MnO 2 constructed by porous nanosheets as the shell. The disordered entanglement of K-CP and MnO 2 nanoflakes significantly increases the interlayer spacing, optimizes the pore distribution, creates favorable conditions for charge and ion transport, and realizes the synergistic effect of electric double layer (EDL) adsorption and Faradaic reactions. The specific capacitance (SC) of K-CP/MnO 2 at 5 mV s −1 is 112.03 F g −1 , which is nearly 3.76 times that of CP (29.82 F g −1 ). At a voltage of 1.2 V (100 mg L −1 ), the electrosorption capacity (SAC) of the K-CP/MnO 2 electrode for Pb 2+ and Zn 2+ is 124.66 and 96.86 mg g −1 , respectively. After 15 adsorption/desorption cycles in the HCDI device, the adsorption capacity for Pb 2+ and Zn 2+ is retained at 86.81% and 82.59%, respectively. The experiments indicate that the removal of Pb 2+ primarily occurs through electrosorption, redox reactions, and surface complexation, while Zn 2+ is inserted into the channel provided by MnO 2 and participates in the solid phase reaction. The K-CP/MnO 2 composite prepared in this study offers a novel approach for designing high-performance HCDI electrodes and achieving the selective removal of heavy metals.
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高影响因子
IONICS
·
2017
·Vol. 24
·期 9
·2583-2590
·
IF 2.062
Wang Xiaoqing,Yin Mingyue,Xue Huidong,Su Yu,Tian Songran
Niobium-doped MnO 2 /reduced graphene oxide (Nb-MnO 2 /RGO) composite has been successfully synthesized via a simple microwave radiation method. The samples were systematically studied by X-ray diffraction (XRD), thermogravimetric analysis (TG), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM), and electrochemical measurements. As the anode material for lithium-ion batteries, the Nb-MnO 2 /RGO (molar ratio of Mn/Nb = 50:1) (NMG50) showed an outstanding reversible discharge capacity of 556.6 mAh g −1 after 50 cycles with a capacity retention of 77% at a charge-discharge rate of 0.1 A g −1 and the reversible discharge capacity can still retain 223.3 mAh g −1 at a current of 1 A g −1 , which is much higher than those for Nb-MnO 2 /RGO (molar ratio of Mn/Nb = 10:1) (NMG10) and undoped MnO 2 /RGO (MG). The improved electrochemical performance could be attributed to the proper amount of Nb doping, which could enhance both the conductivity and the structure stability of MnO 2 .
研究领域:
材料科学
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电化学
·
储能
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高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Mengjie Lin,Wenxin Chen,Cunshan Zhang,Jiewei He,Lina Wu,Ailin Liu,Xinhua Lin,Liqing Lin
Specific-Species enzyme detection serves as a crucial method in foodborne pathogen surveillance. Particularly, endogenous β-galactosidase (β-Gal) enzyme has been widely applied to determine the concentration of Escherichia coli ( E. coli ). The main challenges include reducing analysis time and improving detection sensitivity. A novel strategy for biosensing β-Gal activity and E. coli are developed based on BSA‑manganese dioxide nanosheets (BSA-MnO 2 NS) with the oxidase-mimicking activity to regulate the fluorescence of thiamine. BSA-MnO 2 NS can catalyze the oxidation of non-fluorescent thiamine to generate strong fluorescent dehydrothiamine. When β-Gal enzymes is introduced, p -aminophenyl-β-D-galactopyranoside (PAPG) could be hydrolyzed to form para-aminophenol (PAG), which efficiently reduced BSA-MnO 2 NS into Mn 2+ , resulting in the loss of their oxidase-like activity and the decrease of dehydrothiamine fluorescence. Since endogenous β-Gal in E. coli cells can directly hydrolyze PAPG without destroying bacteria, which greatly reduced the analysis time. The reduction product PAG leads to MnO 2 NS decomposition and thus reduced dehydrothiamine fluorescence. According to this mechanism, fluorescence biosensor for β-Gal activity and E. coli are constructed utilizing thiamine luminescence modulated by BSA-MnO 2 NS, without requiring an additional oxidizer. β-Gal and E. coli showed good linearity in the range of 0.01–2.0 μg/mL and 1.0 × 10 2 –1.0 × 10 4 CFU/mL, and the detection limits reached 8.55 ng/mL and 89.45 CFU/mL, respectively. The proposed enzyme-nanozyme cascade reaction significantly improved the sensitivity. It is highly specific and can be used to distinguish E. coli from other pathogenic bacteria. The strategy has also been successfully applied to the detection of E. coli in real samples.
研究领域:
生物传感
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微生物学
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纳米生物学
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分子诊断
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食品安全检测
·
酶学
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Hui Li,Ziyi Wang,Jingye Zhao,Yuwei Guan,Yueying Liu
A dual colorimetric and ratiometric fluorescent assay is constructed for the detection of glutathione (GSH) based on MnO2 nanosheets (MnO2 NS). Amplex Red (AR) and curcumin (CUR) fluorescence-pairing probes have opposite responses to MnO2 NS with fluorescence quenching and oxidase-like property. MnO2 nanosheets can largely quench the fluorescence of curcumin. However, the fluorescence of oxidized AR (oxAR) was obviously raised via the catalytic oxidation reaction of no fluorescent AR. The color of the solution gradually changes from yellow to orange. However, MnO2 nanosheets lose the fluorescence quenching capacity and oxidase-like property after the addition of GSH. Therefore, the fluorescence intensity of curcumin shows an obvious increase and the intensity of oxAR a decrease, accompanied by the restoration of the solution color from orange to yellow. For MnO2 nanosheets, the linear relationship between the absorbance ratio of the two substrates and the GSH concentration (50–15 000 nM) is obtained with the detection limit of 16 nM. Besides, the ratiometric fluorescent method has a good linear range from 10 to 5000 nM for GSH. The detection limit is as low as 4.2 nM. Further, this method can not only be used for the determination of GSH in an aqueous solution but also shows a high responsive ability to GSH in human serum. This result indicates its potential in bioanalysis and disease diagnosis.
研究领域:
分析化学
·
生物化学
·
纳米技术
·
生物医学工程
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jiangbo Huo,Guoce Yu,Jianlong Wang
In this study, a novel adsorbent, polyvinyl alcohol/graphene oxide/MnO 2 composite was prepared, characterized and used for efficient removal of Co 2+ and Sr 2+ from aqueous solution. Polyvinyl alcohol (PVA) and Mn 2+ played a synergistic role in the gelation of PVA/GO/Mn 2+ , while Mn 2+ can be further converted into oxide to achieve functionalized aerogel (PVA/GO/MnO 2 ). The spectroscopy analysis manifested that hydrogen bonds and electrostatic attraction were responsible for the formation of PVA/GO/MnO 2 . The functionalization of MnO 2 enhanced the adsorption capacity for Co 2+ (2.1 folds) and Sr 2+ (1.3 folds) by PVA/GO/MnO 2 . The composite showed high adsorption capacity at broad pH range of 4.0–9.0. For competitive adsorption test, Ni 2+ /Zn 2+ exerted the most interfering effect on Co 2+ adsorption, while Mg 2+ /Ca 2+ showed severe interfering effect on Sr 2+ adsorption. Both electrostatic attraction and oxygen-containing groups contributed to the adsorption mechanism. This study may provide a new adsorbent for separation of Co 2+ and Sr 2+ from aqueous solution.
研究领域:
环境科学
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材料科学
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PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Xiao Cui,Xinli Chen,Wenjie Zhang,Xiaoqing Yan,Ming Wang,Jiancong Lian,Zhuan Zheng,Hong Deng
Metal oxides with hierachical three-dimensional (3D) superstructure , which integrate large surface area with high electrical conductivity , have been regarded as desirable and ideal electrode materials for supercapacitors . In this work, 3D hierarchical CoMoO 4 @C@MnO 2 core-shell nanorod arrays (NRAs) on nickel foam were fabricated by a facile and stepwise hydrothermal approach. The morphologies of CoMoO 4 and CoMoO 4 @C@MnO 2 were explicitly investigated. The CoMoO4@C@MnO2 based electrodes exhibited excellent capacitive performances. In comparison to the specific capacitance of CoMoO 4 (1080 F g −1 at a current density of 3 A g −1 and 82% retained capacitance over 5000 cycles) The CoMoO 4 @C@MnO 2 based electrodes showed improved performance, delivering specific capacitance up to 1824 F g −1 at 3 A g −1 and 86% retained capacitance over 5000 cycles. The results establish that the binder-free CoMoO 4 @C@MnO 2 is a promising candidate for high performance electrochemical supercapacitors.
研究领域:
材料科学
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电化学
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Nanomaterials
·
2019
·Vol. 9
·期 6
·847
·
IF 4.034
Xuan Wan,Shihui Yang,Zhaotian Cai,Quanguo He,Yabing Ye,Yonghui Xia,Guangli Li,Jun Liu
This study reports facile synthesis of MnO2nanoflowers/N-doped reduced graphene oxide (MnO2NFs/NrGO) composite and its application on the simultaneous determination of dopamine (DA) and uric acid (UA). The microstructures, morphologies, and electrochemical performances of MnO2NFs/NrGO were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), respectively. The electrochemical experiments showed that the MnO2NFs/NrGO composites have the largest effective electroactive area and lowest charge transfer resistance. MnO2NFs/NrGO nanocomposites displayed superior catalytic capacity toward the electro-oxidation of DA and UA due to the synergistic effect from MnO2NFs and NrGO. The anodic peak currents of DA and UA increase linearly with their concentrations varying from 0.2 μM to 6.0 μM. However, the anodic peak currents of DA and UA are highly correlated to the Napierian logarithm of their concentrations ranging from 6.0 μM to 100 μM. The detection limits are 0.036 μM and 0.029 μM for DA and UA, respectively. Furthermore, the DA and UA levels of human serum samples were accurately detected by the proposed sensor. Combining with prominent advantages such as facile preparation, good sensitivity, and high selectivity, the proposed MnO2NFs/NrGO nanocomposites have become the most promising candidates for the simultaneous determination of DA and UA from various actual samples.Keywords:dopamine;uric acid;MnO2nanoflowers;N-doped reduced graphene oxide;voltammetric sensor
研究领域:
分析化学
·
生物医学工程
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高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Fang Liu,Tiantian Lei,Yingli Zhang,Yaping Wang,Yu He
In this work, boron carbon oxynitride quantum dots (BCNO QDs) were prepared by a one-step hydrothermal process of ethanolamine and boric acid . BCNO QDs exhibited blue fluorescence with the optimal excitation/emission fluorescence peak at 335 and 420 nm, respectively. As an efficient fluorescence quencher , manganese dioxide (MnO 2 ) nanosheets can effectively quench the fluorescence of BCNO QDs via the inner filter effect (IFE). Acetylcholinesterase (AChE) catalyzes the hydrolysis of acetylcholine (ATCh) to produce thiocholine (TCh). TCh can reductively degrade MnO 2 nanosheets to generate Mn 2+ , thereby recovering the fluorescence of BCNO QDs. Organophosphorus pesticides (OPs) can inhibit the activity of AChE enzymes , thereby preventing the production of TCh and the decomposition of MnO 2 nanosheets, resulting in the fluorescence “turn-off”. Therefore, the concentration of OPs can be detected by measuring the fluorescence intensity change of AChE-ATCh-MnO 2 -BCNO-QDs system. Under optimal experimental conditions, the dynamic detection range of paraoxon is 0.1–250 ng mL −1 , and the detection limit is 0.03 ng mL −1 . Meanwhile, the reaction system also showed concentration-dependent visual color changes from colorless to brownish. Furthermore, we prepared a portable BCNO QDs test paper. By using a smartphone to identify the RGB values of the reaction solution and the corresponding test paper, we carried out the digital image chromaticity analysis, which can shorten the detection time and reduce the detection cost, and provide an effective solution for the rapid detection of OPs on site.
研究领域:
分析化学
·
环境科学
·
纳米技术
·
传感技术
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高影响因子
RSC Advances
·
2021
·Vol. 11
·期 35
·21760-21766
·
IF 3.361
Zeling Zhang,Benchao Su,Huan Xu,Zhenyun He,Yuling Zhou,Qi Chen,Zhichang Sun,Hongmei Cao,Xing Liu
Ochratoxin A (OTA) is a common food contaminant with multiple toxicities and thus rapid and accurate detection of OTA is indispensable to minimize the threat of OTA to public health. Herein a novel enzyme cascade-amplified immunoassay (ECAIA) based on the mutated nanobody–alkaline phosphatase fusion (mNb–AP) and MnO2 nanosheets was established for detecting OTA in coffee. The detection principle is that the dual functional mNb–AP could specifically recognize OTA and dephosphorylate the ascorbic acid-2-phosphate (AAP) into ascorbic acid (AA), and the MnO2 nanosheets mimicking the oxidase could be reduced by AA into Mn2+ and catalyze the 3,3′,5,5′-tetramethyl benzidine into blue oxidized product for quantification. Using the optimal conditions, the ECAIA could be finished within 132.5 min and shows a limit of detection of 3.38 ng mL−1 (IC10) with an IC50 of 7.65 ng mL−1 and a linear range (IC20–IC80) of 4.55–12.85 ng mL−1. The ECAIA is highly selective for OTA. Good recovery rates (84.3–113%) with a relative standard deviation of 1.3–3% were obtained and confirmed by high performance liquid chromatography with a fluorescence detector. The developed ECAIA was demonstrated to be a useful tool for the detection of OTA in coffee which provides a reference for the analysis of other toxic small molecules.
研究领域:
食品科学
·
分析化学
·
毒理学
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PubMed
高影响因子
FUEL
·
2023
·
IF 7.4
Xu Wu,Heqin Guo,Litao Jia,Yong Xiao,Bo Hou,Yongxiang Gao,Debao Li
δ-MnO 2 shows potential application in furfural base-free oxidation to furoic acid. While, its catalytic mechanism was unclear, which limited the further improvement of the catalytic activity . Therefore, three δ crystal MnO 2 with different hydroxyl and active oxygen species concentrations were prepared and applied in the furfural oxidation reaction. IR, Furfural-IR, O 2 -TPD, H 2 O- 18 O 2 -TPD, and XPS techniques characterized the hydroxyl and active oxygen species. The results show that the hydroxyl group on δ-MnO 2 is important in absorbing and attacking furfural to form geminal diol intermediate. Moreover, two types of oxygen species O -OH and O ads originating from the surface hydroxyl and the strongly adsorbed gas-phase O 2 , respectively, play an essential role in defhydrogenating geminal diol to furoic acid. Most importantly, the hydroxyl, O -OH , and O ads consumed on δ-MnO 2 can be reconstructed under reaction conditions. Among the three δ crystal MnO 2 , δ-MnO 2 , with the most abundant hydroxyl and active oxygen species, exhibited the best catalytic performance with 99.53% furfural conversion and nearly 100% furoic acid selectivity. This work identifies the function of hydroxyl and active oxygen species on δ-MnO 2 in furfural oxidation reaction, guiding the design of a non-noble metal catalyst for furoic acid synthesis under base-free conditions.
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