Nanoscale Horizons
·
2022
·Vol. 8
·期 3
·338-345
·
IF 11.684
Jie Wu,Xuetao Qin,Yu Xia,Yuanyuan Zhang,Bin Zhang,Yunchen Du,Hsing-Lin Wang,Siwei Li,Ping Xu
Transition metal sulfides (TMSs) are promising electrocatalysts for hydrogen evolution reaction (HER), while TMSs usually suffer from inevitable surface oxidation in air, and the impact of the surface oxidation on their HER catalytic activity remains unclear. Herein, we demonstrate an effective strategy for reducing the surface oxidation degree of easily oxidized CoS2 by introducing glued vanadium pentoxide (V2O5) nanoclusters, taking advantage of the preferential adsorption and strong interaction between high-valence V and O2. Combining oxidation protection and elaborate oxidation control experiments reveal that reduced surface oxidation degree of CoS2 is conducive to affording promising HER catalytic performance, as the oxidized surface of CoS2 can hinder the dissociation of water and thus is harmful to the HER process. Direct evidence is provided that surface oxidation should be carefully considered for TMS-based HER catalysts. The present work not only develops a new strategy for protecting CoS2 from surface oxidation, but also provides deep insight into the impact of surface oxidation on the HER performance of transition metal compounds.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2018
·
IF 9.89
Hui Chen,Lei Sun,Guo-Dong Li,Xiaoxin Zou
Surface oxygen chemistry of semiconductor metal oxides is the basis for the sensing reaction between the preadsorbed surface oxygen and the target gases or organic vapors that are to be detected, and thus fundamentally determines their sensing performances. Herein, we, for the first time, identify a novel semiconductor spinel oxide, CdGa2O4, that has suitable surface oxygen chemistry and exhibits excellent selectivity and response toward formaldehyde. Moreover, we find that a cation off-stoichiometric CdGa2O4 spinel oxide decorated with a small amount of CdO nanocrystals can further improve the formaldehyde response, without losing the selectivity. This is based on the advantages of an increased amount of adsorbed oxygen in the Ga-rich environment, as well as heterojunctions between CdO nanoparticles and Ga-rich spinel oxide. Sensing performance (e.g., selectivity and response) of the material is much better than that of most reported nanostructured metal oxides used for formaldehyde detection. Our findings propose a general approach for achieving highly selective and sensitive detection of target gases by optimizing the surface oxygen property of semiconductor oxides.
研究领域:
材料科学
·
传感器技术
·
化学
✓ 已验证
DOI
高影响因子
Bioresource Technology Reports
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2022
·
IF 0
Sen Lin,Yihong Guo,Lei Zhou,Hongjun Yang
Quantitative effects of surface oxidation on Cd 2+ adsorption performance of biochar derived from long-root Eichhornia Crassipes plants were systematically investigated. It was revealed that oxidation degree was positively related with the intensity of surface functional groups and harmless for the structural stability, while biochar yield would decline sharply resulting from for over-oxidization. Correspondingly, the Cd 2+ adsorption capacity exhibited an uptrend with the increasing oxidation on account of the abundant adsorption sites. Moreover, Cd 2+ adsorption on the biochar with different oxidation degrees were also investigated comprehensively, indicating adsorption performances in a similar trend highly sensitive to solution pH and ionic strength . In addition, the adsorption isotherms were found to manifest the saturated adsorption capacity for Cd 2+ increased from 0.333 mol/g to 0.487 mmol/g at 30 °C by strengthening oxidation. All synthesized biochar could keep consistent adsorption performance in multiple adsorption-desorption cycles.
研究领域:
环境科学
·
材料科学
·
生态学
✓ 已验证
DOI
GREEN CHEMISTRY
·
2017
·Vol. 19
·期 15
·3611-3617
·
IF 9.125
Meng Li Liu,Lin Yang,Rong Sheng Li,Bin Bin Chen,Hui Liu,Cheng Zhi Huang
Photoluminescent (PL) carbon dots (CDs) as a new type of carbon nanomaterial have attracted increasing attention owing to their fascinating properties. Herein, we develop a facile, energy-efficient, large-scale route to prepare highly PL CDs with a quantum yield of up to 35.3% at room temperature. These PL CDs can be further separated out into green-emissive amorphous carbon nanodots (CNDs) and yellow-emissive crystalline graphene quantum dots (GQDs) through a silica gel column. Both the as-prepared CNDs and GQDs, even when having the same particle-size distribution and chemical groups, have different degrees of surface oxidation. As characterized by X-ray photoelectron spectroscopy (XPS), the yellow-emissive crystalline GQDs have a much higher surface oxidation degree than that of the green-emissive amorphous CNDs. A further finding is that the characteristic emission peaks of the CDs show an obvious red shift from 518 nm to 543 nm with the increase in the surface oxidation degree, which can be attributed to the decrease in their band gap between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO). That is, the difference in band gap is closely related to the oxidation degree of the CDs, rather than the particle size or chemical groups. Moreover, the amorphous CNDs are very easily photobleached under 140 W xenon lamp irradiation as compared to the crystalline GQDs, indicating that the photostability is dependent on the crystalline structure of the CDs, which is beneficial for the top-down design and development of suitable CDs for different application purposes.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Yun-Long Mu,Qing He,Chun-Yan Li,Da Sheng,Song-Hai Wu,Yong Liu,Hai-Tao Ren,Xu Han
Although precise regulation of the crystalline structures of metal oxides is an effective method to improve their antibacterial activities, the corresponding mechanisms involved in this process are still unclear. In this study, three kinds of cuprous oxide (Cu2O) samples with different structures of cubes, octahedra, and rhombic dodecahedra (c-Cu2O, o-Cu2O, and r-Cu2O) have been successfully synthesized and their antibacterial activities are compared. The antibacterial activities follow the order of r-Cu2O > o-Cu2O > c-Cu2O, revealing the significant dependence of the antibacterial activities on the crystalline structures of Cu2O. Quenching experiments, as well as the NBT and DPD experiments indicate that ≡CuII─OO• superoxo and ≡CuII─OOH peroxo, instead of •OH, O2•–, and H2O2, are the primary oxidizing species in the oxidative damage to E. coli. Raman analysis further confirms the presence of both ≡CuII─OO• superoxo and ≡CuII─OOH peroxo on the surface of r-Cu2O. On the other hand, the NCP experiment reveals that Cu+, instead of Cu2+, also contributes to the antibacterial process. This study provides new insight into the antibacterial mechanisms of Cu2O.
研究领域:
材料科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Jiaqiao Yuan,Hongyu Lu,Xiang Gong,Mingjun Chen,Hao Lai,Shuming Wen,Shaojun Bai,Dandan Wu
The development of high-efficiency beneficiation processes for ilmenite has garnered widespread attention. This study proposed the utilize of a heterogeneous Fenton catalytic technology involving H 2 O 2 and Fe 2+ to enhance ilmenite flotation. The flotation results indicated that pre-oxidation of ilmenite with H 2 O 2 -Fe 2+ before adding collector could recover over 80 % of ilmenite from titanaugite. Electron Paramagnetic Resonance and slurry iron component concentration analyses revealed that the •OH generated within the ilmenite-H 2 O 2 -Fe 2+ catalytic system could oxidize Fe 2+ to Fe 3+ . The stronger binding capability of Fe 3+ with NaOL led to a remarkable discrepancy in floatability between ilmenite and titanaugite. Zeta potential analysis further confirmed that the oxidation degree of the ilmenite surface and the adsorption of iron species were higher than those of titanaugite. Additionally, Time-of-Flight Secondary Ion Mass Spectrometry and X-ray photoelectron spectroscopy analyses provided evidence for the selective activation of ilmenite by the H 2 O 2 -Fe 2+ . Furthermore, Density Functional Theory calculations revealed that the stable adsorption of Fe 2+ and Fe(OH) 2 + offered additional active sites on the ilmenite surface for NaOL adsorption. Moreover, the adsorption of •OH significantly affected the electronic spin density of the Fe 3d orbitals of Fe atom in ilmenite, and played a crucial positive in the surface activity of ilmenite.
研究领域:
矿物加工工程
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS ES&T Engineering
·
2024
·
IF 7.4
Shiyu Cao,Lin Zhang,Cancan Ling,Furong Guo,Meiqi Li,Chuan Liang,Jundi Cheng,Yanbiao Shi,Hongwei Sun,Lizhi Zhang
Mackinawite (FeS) is an excellent Cd(II) removal material but suffers from rapid reactivity loss. Herein, we demonstrate that rational surface preoxidation could enhance the single maximum adsorption capacity of mackinawite from 625.0 to 666.7 mg g–1 and also promote its air stability and reusability for long-term application. The Cd(II) removal processes were carefully characterized with a multifunctional in situ electrochemical device, theoretical calculation, and extended X-ray absorption fine structure (EXAFS) spectroscopy. Characterization results revealed that surface preoxidation treatment changed the Cd(II) removal mechanism from ion exchange to ion-exchange coupled surface adsorption because surface preoxidized FeS possessed abundant surface −OH sites. This extra surface adsorption process offered surface preoxidized FeS a superior long-term Cd(II) removal performance of 1290.5 mg g–1 in 5 successive cycles, much higher than that of pristine FeS (842.4 mg g–1). This study highlights the importance of surface oxidation on the Cd(II) removal performance of mackinawite and also opens a new strategy to design and produce high-performance mackinawite nanocrystals for pollutant control and environmental remediation.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2024
·
IF 5.5
Linquan Dai,Bo Feng,Yutao Guo
Background Sphalerite and galena often exist in mixed form and are difficult to separate effectively. The effect of surface oxidation behavior regulation on the depression of calcium lentisulfonate (CLS) was studied in galena and sphalerite. Methods Flotation experiment, contact angle experiment, X-ray photoelectron spectroscopy (XPS) analysis and microcalorimetric experiment were used to study the effect and mechanism of modulation of surface oxidation behaviour on CLS on the depression of galena flotation. Significant findings The results show that CLS can depress both galena and sphalerite. The oxidizing agent H 2 O 2 oxidizes galena significantly faster than sphalerite. The treatment with H 2 O 2 induces the formation of more oxidation products, such as PbSO 4, on the surface of galena, enhances the adsorption of CLS and makes the surface of galena hydrophilic, thus reducing the recovery of galena in the flotation process. On the other hand, the treatment of the activator ethylenediaminetetraacetic acid (EDTA) reduces the amount of oxidation products ZnSO 4 on the sphalerite surface, and CLS loses the active site that can be adsorbed on the galena surface, making the galena surface hydrophilic. In view of the huge hydrophobicity difference between sphalerite and galena, flotation separation is achieved.
研究领域:
矿物加工工程
·
材料科学与工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Kang Feng,Dandan Wu,Jing Cao,Jianan Li,Shaojun Bai
Bornite and arsenopyrite are common sulfide minerals in copper ores. The similar physicochemical properties of these minerals pose challenges for their effective separation through traditional flotation methods. This study systematically investigated the impact of sodium persulfate (Na 2 S 2 O 8 ) treatment on the flotation performance of both bornite and arsenopyrite through single-mineral and artificially mixed mineral flotation tests. The artificially mixed flotation experiment revealed that at an initial pH of 4, a Na 2 S 2 O 8 concentration of 5 × 10 −3 mol/L and NaBX (5 × 10 −5 mol/L), bornite and arsenopyrite exhibited recoveries of 80.01 % and 24.04 %, respectively. The effects of Na 2 S 2 O 8 on mineral surfaces were analyzed through contact angle measurement, atomic force microscopy, scanning electron microscopy–energy dispersive spectroscopy, zeta potential measurement, and local electrochemical impedance spectroscopy. The results confirmed that Na 2 S 2 O 8 treatment significantly altered the arsenopyrite surface but had a small impact on the bornite surface. X-ray photoelectron spectroscopy analysis revealed that Na 2 S 2 O 8 treatment generated numerous hydrophilic oxides on the arsenopyrite surface, such as sulfates and arsenates, which increased its hydrophilicity and reduced floatability. This study provides theoretical insights into the separation of copper and arsenic in copper ores to reduce environmental pollution.
研究领域:
矿物加工工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2024
·Vol. 17
·期 21
·5145
·
IF 3.1
Siqi Lv,Yujian Liang,Xuezhen Zhang,Xiaomei Tan,Zuotan Huang,Xuan Guan,Chongmin Liu,Zhihong Tu
Pyrite is one of the most abundant metal sulfide tailings and is susceptible to oxidation, yielding acidic mine drainage (AMD) that poses significant environmental risks. Consequently, the exploration of pyrite surface oxidation and the kinetic influencing factors remains a pivotal research area. Despite the oxidation of pyrite producing a significant amount of sulfate (SO42−), a comprehensive investigation into its influence on the oxidation process is lacking. Leveraging pyrite’s semiconducting nature and the electrochemical intricacies of its surface oxidation, this study employs electrochemical techniques—cyclic voltammetry (CV), Tafel polarization, and electrochemical impedance spectroscopy (EIS)—to assess the effect of SO42⁻ on pyrite surface oxidation. The CV curve shows that SO42−does not change the fundamental surface oxidation mechanism of pyrite, but its redox peak current density decreases with the increase in SO42−, and the surface oxidation rate of pyrite decreases. The possible reason is attributed to SO42−adsorption onto pyrite surfaces, blocking active sites and impeding the oxidation process. Furthermore, Tafel polarization curves indicate an augmentation in polarization resistance with elevated SO42−concentrations, signifying heightened difficulty in pyrite surface reactions. EIS analysis underscores an increase in Weber diffusion resistance with increasing SO42⁻, indicating that the diffusion of Fe3+to the pyrite surface and the diffusion of oxidized products to the solution becomes more difficult. These findings will improve our understanding of the influence of SO42−on pyrite oxidation and have important implications for deepening the understanding of surface oxidation of pyrite in the natural environment.
研究领域:
环境科学
·
电化学
·
矿物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Xuejiao Liu,Beibei Pan,Zhiwei Li,Poonnawit Hanphaiboon,Yin Wang
Activated carbon supported nanoscale zero-valent iron (NZVI/AC) has been proved to be versatile for removing several kinds of contaminants from environmental matrix. The structural properties of NZVI/AC composites play a crucial role in determining both the decontamination efficiency and adsorption capacity of these materials. However, studies relevant to structural evolution and corresponding manipulation routes for AC-supported NZVI are still scarce. Herein, AC-supported NZVI were prepared under different synthesis conditions followed by characterizing them using several techniques and evaluating their reactivity toward heavy metal in aqueous solution. NZVI/AC synthesized under different molecular weight of PEG and m AC :m Fe possessed a similar removal efficiencies of Pb(II) from aqueous solution, meanwhile, NZVI/AC synthesized with a suitably prolonged time at n BH4 :n Fe = 8.0 exhibited obvious enhancement for Pb(II) removal from aqueous solution. As for structural evolution of AC-supported NZVI, results show that the crystallization was more complete, the shape was converted from needle to sphere, the particle size was becoming smaller, the particle distribution was more homogeneous, the specific surface area was smaller, and the surface oxidation was lower as suitably increasing m AC :m Fe , n BH4 :n Fe , and reaction time. The size and density of iron precursor by complexation of PEG and Fe 2+ , and ratio of nuclei formation to growth values are essentially responsible for manipulating structure of AC-supported NZVI. Spherical AC-supported NZVI with higher iron content based on smaller particle size, uniform distribution, and lower surface oxidation in one is responsible for significant enhancement of Pb(II) removal rate and capacity thanks to higher surface reactivity, more accessible surface-active sites, and faster electron transfer from core to shell of iron. This study would provide a new insight into comprehending manipulation mechanism for the key structure of AC-supported NZVI composites for aquatic remediation.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Sheng-Jin He,Ling-Feng Su,Chuang-Tian Zhan,Xiu-Bin Chen,Wei-Ming Guo,Shi-Kuan Sun,Li-Xiang Wu,Jia-Xiang Xue,Hua-Tay Lin
Low-temperature joining of SiC ceramics using raw CaO-Al 2 O 3 -MgO-SiO 2 mixed powders (CAMS-P) and CaO-Al 2 O 3 -MgO-SiO 2 glass (CAMS-G) as additives for the liquid-phase sintering of SiC nanopowders (NITE phase) in combination with surface oxidation was studied. Using CAMS-P as an additive for SiC joining required 1650 °C and produced a lower shear strength of 77.2 ± 3.5 MPa, compared to untreated SiC (108.2 ± 15.8 MPa). Using CAMS-G as an additive, the compactness of SiC joints obtained at 1550 °C was higher than that of NITE joints obtained at 1650 °C with CAMS-P as an additive. Nonetheless, the low joining temperature resulted in gaps and delaminations at the interface, and the joints strength was only 48.3 ± 5.6 MPa. Incorporating CAMS-G as an additive and surface oxidation achieved reliable NITE phase joining at 1550 °C, with no observed gaps or delaminations at the interface. The resulting joints strength was as high as 100.0 ± 0.8 MPa. The joining mechanism was discussed and compared, involving microstructural analysis .
研究领域:
材料科学
·
陶瓷工程
✓ 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）