INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2017
·
IF 3.582
Pan Wang,Ji Qi,Xiaozhen Chen,Chuang Li,Tonghua Wang,Changhai Liang
Hydrogen evolution reaction (HER) is considered to be one of the most promising strategies to create hydrogen. Recently, searching high-efficient, stable, and earth-abundant electrocatalysts to replace precious metals for practical utilizations of HER is attracting more and more attentions. Herein, novel molybdenum carbide nanobelts containing Mo of high-valence state derived from MoO 3 -ethylenediamine inorganic/organic hybrid precursors are successfully synthesized via a facile one-pot pyrolysis method. The molybdenum carbide nanobelts are characterized using XRD , SEM, TEM and XPS . Moreover, the high-valence state Mo and their relative content in the molybdenum carbide nanobelts can be identified by XPS. The high-resolution XPS spectra of Mo 3d indicates in the molybdenum carbide nanobelts the proportion of high-valence state Mo in active Mo components is 51.3%. More importantly, the as-synthesized products exhibit excellent electrocatalytic activity for HER with a low onset overpotential of 50 mV and a small Tafel slope of 49.6 mV dec −1 in acidic medium (0.5 M H 2 SO 4 ). Besides, the catalysts require only overpotentials of 143 and 234 mV to achieve current densities of 10 and 220 mA cm −2 , respectively. Furthermore, they also exhibit good durability after 2000 cycles and constant current density test. Such excellent electrocatalytic HER performance can be ascribed to the high intrinsic activity of high-valence state Mo in Molybdenum Carbide. Synthesizing molybdenum carbide with high-valence state Mo electrocatalysts for HER will open up an exciting alternative avenue to acquire outstanding HER electrocatalytic activity.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2021
·Vol. 11
·期 9
·1079
·
IF 4.146
Song Zhou,Xi Liu,Jian Xu,Hui Zhang,Xiaosong Liu,Pengcheng Li,Xiaodong Wen,Yong Yang,Yongwang Li
As an alternative to noble metal hydrogenation catalysts, pure molybdenum carbide displays unsatisfactory catalytic activity for arene hydrogenation. Precious metals such as palladium, platinum, and gold are widely used as additives to enhance the catalytic activities of molybdenum carbide, which severely limits its potential applications in industry. In this paper, iron-promoted molybdenum carbide was prepared and characterized by various techniques, including in situ XRD, synchrotron-based XPS and TEM. while the influence of Fe addition on catalytic performance for toluene hydrogenation was also studied. The experimental data disclose that a small amount of Fe doping strongly enhances catalytic stability in toluene hydrogenation, but the catalytic performance drops rapidly with higher loading amounts of Fe.Keywords:molybdenum carbide;Fe-promoter;toluene hydrogenation;synchrotron-based XPS;in situ XRD
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Yifan Zhou,Aosong Gao,Mingqiu Duan,Xiaoqi Zhang,Muzi Yang,Li Gong,Jian Chen,Shuqin Song,Fangyan Xie,Hao Jia,Yi Wang
Garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZTO) is a highly promising solid-state lithium metal battery electrolyte due to its exceptional ionic conductivity and electrochemical stability. However, when exposed to air, a passivation layer can be spontaneously formed on the garnet-type electrolyte, deteriorating its wettability with metallic lithium (Li) and impeding the lithium ion transfer at the Li–garnet electrolyte interface. The passivation layer is considered a critical issue for garnet-type solid electrolytes. Despite intensive research, the formation mechanism of the passivation film remains poorly understood. The key to elucidating the formation mechanism is to obtain a pristine garnet electrolyte surface and study how the pristine garnet electrolyte interacts with air. In this study, different passivation layer removal pretreatments were performed to expose pristine garnet electrolytes, and their impacts on the samples were systematically studied. The results reveal the overlooked negative impacts of vacuum annealing and acid treatment on LLZTO, which are indicated by the severe loss of Li and O and the formation of additional Li-depleted metal oxides. It was confirmed that argon annealing is the only viable approach to remove the passivation layer without introducing concomitant contaminations to LLZTO. Based on this method, we directly evidenced the formation of LiOH on LLZTO under rarefied air using quasi-in situ X-ray photoelectron spectroscopy. It was confirmed that the loss of Li and O ions, rather than Li+/H+ exchange, drives the formation of LiOH in the passivation layer. These results not only provide a better understanding of the surface and interface chemistry of LLZTO but also reveal a reliable surface treatment for the LLZTO sample.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2024
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IF 5.3
Guanai Qu,Hongling Fang,Yi Li,Songwei Zhang,Litian Hu
Since the lubrication performances of ionic liquids are closely linked to their unique structures, four protic ionic liquids (PILs), [N 44 HH][DEHP], [N 444 H][DEHP], [N 448 H][DEHP] and [N 4412 H][DEHP], are designed to investigate the effect of cationic structures on the lubrication behaviors and lubrication mechanisms. Vacuum tribological tests were carried out to minimize the impact of the atmospheric environment. The structure–activity relationships and lubrication mechanisms of PILs were emphatically examined by in-situ quadrupole mass spectrometer (Q-MS) and XPS analyses. Results demonstrated that all four PILs exhibited outstanding lubrication performance under a vacuum condition. Unusually, extended alkyl chain cationic structures resulted in a changed lubrication mechanism, leading to a slight decrease in performance. In-situ Q-MS analyses and XPS further revealed that the length of the alkyl chain in cations influenced the strength of intermolecular forces in PILs, leading to changes in their lubrication performance and mechanisms.
研究领域:
材料科学
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表面工程
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化学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
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2021
·
IF 4.765
Yuankai Xu,Zhitao Yuan,Qingyou Meng,Xuan Zhao,Yusheng Du
The mixed BHA/NaOL collector was studied to improve the floatability of ilmenite in the presence of lead ions. The mechanism was discussed through surface tension measurements, zeta potential measurements, adsorption amount measurements, and XPS analysis. Microflotation results show that the mixed BHA/NaOL collector exhibited a better performance on the floatability of ilmenite than single BHA and NaOL collector. The recovery of ilmenite was 92.9% when the molar ratio of BHA/NaOL was set to 7:3. The adsorption amount of mixed collectors on the ilmenite surface was greater than that of equivalent single BHA and NaOL. The results of surface tension suggest that there was synergism between BHA and NaOL in aqueous solution. Zeta potential results indicate that mixed BHA/NaOL adsorbed onto ilmenite surface and had a more negative shift than single BHA. XPS results further confirm that BHA and NaOL adsorbed onto the ilmenite surface through chemisorption and hydrogen bonds.
研究领域:
矿物加工
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表面化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Minerals
·
2023
·Vol. 13
·期 10
·1337
·
IF 2.5
Jiaqian Zhang,Zhe Wang,Ying Luo,Zhenlong Zhang,Xiyang Feng,Qiuping Zeng,Duan Tian,Chao Li,Yongde Zhang,Shu Chen
To enhance the sorption efficacy of attapulgite for heavy metals, mercapto-functionalized attapulgite (ATP-SH) was synthesized with mercaptan functional groups. When the mass-to-volume ratio of calcined attapulgite (ATP-C) to 3-Mercapropyltrimethoxysilane (MPTMS) was 1 g:0.5 mL (ATP-SH-0.5) and the pH was set to 8, a strong adsorption capacity for Cd (II) and Pb (II) was demonstrated. This indicates excellent adsorption performance for these heavy metals. ATP-SH-0.5 exhibited a maximum adsorption capacity of 43.81 mg/g and 274.83 mg/g for Cd (II) and Pb (II), respectively, in a single ion system. In a binary ion system, the maximum adsorption capacity was 31.86 mg/L and 254.45 mg/L for Cd (II) and Pb (II), respectively. Various characterizations and experiments showed that the adsorption of Cd (II) and Pb (II) onto ATP-SH-0.5 involves ion exchange reactions involving hydroxyl and thiol functional group complexation reactions. This adsorption process follows a single-molecule layer adsorption mechanism. XPS results indicate that hydroxyl and grafted thiol functional groups on the surface of mercapto-functionalized attapulgite participated in surface complexation reactions with Cd (II) and Pb (II), resulting in the formation of Cd-S and Pb-S species. Overall, this study provides a promising mercapto-functionalized modification material for the remediation of polluted water and soil.Keywords:attapulgite;thiol functional group;heavy metal;adsorption mechanism;XPS qualitative analyses
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
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2017
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IF 4.233
Chenhu Zhang,Sun Wei,Yuehua Hu,Honghu Tang,Jiande Gao,Zhigang Yin,Qingjun Guan
Selective adsorption of tannic acid (TA) on calcite surfaces and the implications of this process for the separation of fluorite ore were studied by microflotation tests, surface adsorption experiments, zeta potential measurements, UV–vis analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The microflotation tests indicated that TA, when added before sodium oleate (NaOl), could selectively depress calcite from fluorite at pH 7. Surface adsorption experiments revealed that TA hinders the interaction of NaOl with calcite. The zeta potential of calcite became more negative with TA than with NaOl. However, the characteristic features of TA adsorption were not observed on fluorite, suggesting that the dominant adsorption sites are dissimilar on the fluorite and calcite surfaces in the pulp. UV–vis spectroscopy, XPS, and solution chemistry analysis were utilized to obtain a better understanding of the mechanism for selective adsorption of TA as well as the key factors determined by the Ca 2+ and Ca(OH) + components on the mineral surfaces. A possible adsorption mechanism along with an adsorption mode is proposed for the surface interaction between TA and calcite.
研究领域:
矿物加工工程
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表面化学
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胶体与界面科学
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资源利用
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浮选化学
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
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2017
·Vol. 29
·期 4
·044002
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IF 3.44
Liang Huang,Chengpeng Jiao,Liqiong Wang,Zili Huang,Feng Liang,Simin Liu,Yuhua Wang,Haijun Zhang,Shaowei Zhang
ISOBAM-104 protected Rh/Ag bimetallic nanoparticles (NPs) with average diameter less than 3.0 nm were synthesized by a co-reduction method. Ultraviolet–visible spectroscopy, transmission electron microscopy (TEM), high-resolution TEM and x-ray photoelectron spectroscopy (XPS) were employed to characterize the structure, particle size, and electronic structure of the prepared bimetallic NPs. The catalytic activities of prepared bimetallic NPs for hydrogen generation from hydrolysis of a basic KBH4 solution were evaluated in detail. The results indicated that as-prepared Rh/Ag bimetallic NPs showed a higher catalytic activity than corresponding monometallic NPs. Among all the monometallic NPs and bimetallic NPs, Rh80Ag20 bimetallic NPs exhibited the highest catalytic activity with a value of 6010 mol-H2·h−1·mol-catalyst−1 at pH = 12 and 303 K. The high catalytic activities of Rh/Ag bimetallic NPs could be attributed to presence of negatively charged Rh atoms and positively charged Ag atoms, which is supported by the results of XPS and density functional theory calculation. Based on the kinetic study, the apparent activation energy for the hydrolysis reaction of the basic KBH4 solution catalyzed by Rh80Ag20 bimetallic NPs was about 47.0 ± 3.9 kJ mol−1.
研究领域:
材料科学
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催化化学
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Chenhu Zhang,Yuehua Hu,Wei Sun,Jihua Zhai,Zhigang Yin,Qingjun Guan
In this study, the effect of phytic acid (PA) on the surface properties of scheelite and fluorite was systematically investigated. PA was spontaneously adsorbed onto fluorite through electrostatic and chemical adsorption . By contrast, PA did not appear on the scheelite due to the reaction conditions, surface site, and steric hindrance . XPS measurements were utilized together with a solution chemistry analysis to understand better both the PA selective adsorption mechanism and the key factors derived from multi-layer adsorption onto fluorite, which was found to hinder completely that of NaOl.
研究领域:
矿物加工
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表面化学
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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
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2017
·
IF 2.714
Zhongchuan Peng,Huayi Li,Qian Li,Youliang Hu
Carbon nanoforms (CNFs, including graphene, carbon nanotube and fullerene) were functionalized via microwave-assisted thiol-ene click chemistry. Different functional CNFs with −COOH, −NH 2 , −NH 3 Cl,-Si(OCH 3 ) 3 , alkyl and furyl groups were obtained and characterized by XPS, EDS, TGA, Raman spectroscopy and MALDI-TOF MS. Microwave was much more efficient to promote reactions than traditional thermal method. XPS confirmed the binding energy of C-S-C (163.3ev) the modified CNFs. Raman spectroscopy showed increasing I D /I G and A D /A G of graphene and CNT after thiol-ene addition reaction. The result of MALDI-TOF MS indicated that the thiol-containing molecules were attached on fullerene. All these results indicated the successful thiol-ene click reactions between CNFs and thiol-containing molecules under microwave. TGA analysis results showed the mass loss of the modified CNFs, which provided that AIBN and 3-merlaptopropionic acid were the most efficient initiator and monomer, respectively. In summary, the microwave-assisted thiol-ene click reaction provided a powerful chemical tool for the preparation of functional CNFs materials.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2021
·
IF 5.134
Qingqing Hu,Donglai Ma,Yongjie Liu,Qingyun Huang,Zhixiong You,Xuewei Lv
Ferrochromium nitride is an important alloying additive for smelting nitrogen–containing steel. Preparing nitrides by using ammonia gas as reducing and nitriding agent is characterized by high–efficiency and carbon free. In this study, the reaction behavior between chromite spinel and ammonia gas was investigated. Thermodynamic analysis revealed that the reaction was feasible. The transformation of chromite spinel as well as the final products were dependent on reaction temperature, time and input fraction of ammonia gas. The experimental results proved the effect of reaction parameters on the reduction and nitridation process. Chromite spinel was reduced and nitrided to form metallic iron and CrN at temperatures below 950 °C, while metallic iron and Cr 2 N were the main products at 1000 °C. XPS analysis also proved the existence of CrN and Cr 2 N. Ferrochromium nitride with N content treater than 15 wt% was obtained when reducing above 950 °C for 3 h.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Xun Li,Xuanying Lu,Bingtao Gui,Cheng Wang,Jun Liu,Liang Lu
Seawater uranium extraction is a key technology for environmental sustainability with significant potential applications. For the first time, this work synthesized a CTAB/Bent-MOF808 with strong stability, abundant coordination functional groups, and low cost, and assessed its adsorption effectiveness for U (VI) in carbonate solutions. The study explores how pH, contact time, uranium concentration, temperature, carbonate, halide salts, phosphorus, and Ca/Mg ions influence uranium adsorption, with a focus on mechanistic insights through characterization and modeling. Under optimal conditions (temperature of 25 °C, pH 8.0, with a sodium bicarbonate concentration of 2 mmol L −1 and a U(VI) concentration of 50 mg L −1 ), which are similar to the real seawater environment, CTAB/Bent-MOF808 demonstrated superior uranium adsorption performance compared to MOF808 and CTAB/Bent in U(VI)–CO 3 solutions. Under high initial pH, NaHCO 3 , Ca/Mg ions, and halide ion concentrations, the complex's uranium adsorption capacity and removal rate are reduced due to competitive adsorption between ions, as well as increased electrostatic repulsion on the surface. The sorption process was identified as monolayer homogeneous chemical adsorption process by analyzing it with quasi second order kinetic models and Langmuir isotherm models. The inhibitory effect of halide ions is as follows: I − > F − > Br − > Cl − . XPS suggested that the complexation of bromide anion with –COOH and electrostatic attraction could be crucial processes for uranium adsorption. This study offers theoretical insights into uranium extraction from natural uranium-bearing waters and highlights the expanded potential of MOF-based adsorbents in this process, enhancing both efficiency and application scope.
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
危险品化学品经营许可证（带存储）