Journal of Magnesium and Alloys
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2021
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IF 10.088
Baojing Feng,Guonan Liu,Peixu Yang,Sensen Huang,Dongqing Qi,Peng Chen,Chengduo Wang,Jiang Du,Shaojun Zhang,Jinhui Liu
Effect of the second phase in the micro-galvanic corrosion of a commercial Mg alloy containing rare earth elements, cast WE43 alloy, was investigated in 0.6 M NaCl solution and 0.6 M Na 2 SO 4 solution by scanning electron microscopy (SEM) observations, scanning Kelvin probe force microscopy (SKPFM) analysis, hydrogen evolution, weight loss measurement, and electrochemical techniques. It is confirmed that the second phase of cast WE43 alloy is more active than Mg matrix and exhibits an anodic role in the micro-galvanic corrosion with α-Mg matrix as cathode and dissolves preferentially in Na 2 SO 4 solution, in contrast to the situation in NaCl solution. The corrosion rate of cast WE43 alloy in Na 2 SO 4 solution is much higher than that in NaCl solution, which is different from the conventional wisdom and could be attributed to the different role of the second phase in the micro-galvanic corrosion in two solutions.
研究领域:
材料科学
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腐蚀科学
✓ 已验证
产品关联
DOI
高影响因子
STUDIES IN CONSERVATION
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2019
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IF 0.797
Jing Zhao,Hongjie Luo,Xiao Huang
Currently, there is a lack of research on the migration and distribution of soluble salt solutions in the pores of fragile silicate cultural relics, especially the thermodynamic changes during crystallization, and the forces causing the destruction of cultural relics. Thus, this paper used infrared thermal imaging analysis and extended depth-of-field microscopy to observe the changes in temperature, morphology, migration, and crystallization rate of Na2SO4 solution – the most typical solution that causes damages to cultural relics – in the crystallization process and in different capillary pores. The results show that the formation of soluble salt crystal nuclei and subsequent crystal growth mainly occurred in the liquid phase region below the ambient temperature, and then the salt crystals in the deliquescent state became more compact due to the attractive force generated from liquid-phase water evaporation. Additionally, three stages of migration and crystallization of the salt solution in different capillary pores were found. Large-area crystals appeared in the capillary pore with a large diameter, and bubbles were generated. This is likely because the surface tension of the Na2SO4 solution decreased with increasing concentration, and the solubility of the air dissolved at the solid–liquid interface of the mouth of the capillary pore and the pressure in the capillary pore decreased. A self-designed double-layer contact surface internal pressure method and extended depth-of-field microscopy were used to carry out real-time online observation of the force applied on the contact surface during the crystallization of the salt solution. It was found that the airflow determined the direction of capillary movement of the solution, and water migration determined the laminar flow in the capillary pore. Salt crystallization played a role in distortion and shape-fixation of pores. Small spikes in the mass indicated that the expansion–contraction force generated by the salt solution during the crystallization process was in a state of constant change, and the degree of expansion was always slightly more significant than the change caused by contraction. Expansion forces dominated the surface of the sample. In this paper, the change in crystallization and the forces of the soluble salt solution were analyzed.
研究领域:
文物保护
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材料科学
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热力学
✓ 已验证
DOI
高影响因子
CHEMICAL PAPERS
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2025
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IF 2.5
Chen Min,Liu Aimin,Kong Lingyu,Liu Fengguo,Li Song,Liu Yubao,Shi Zhongning
Graphene has been widely studied due to its unique structure and exceptional performance. Various methods are available for preparing graphene, and the electrochemical exfoliation method is chosen for its environmentally friendly, ease of operation, and strong controllability. However, the process of electrochemical exfoliation preparation is influenced by various factors, which still shows challenges of slow exfoliation speed and low yield. In this study, high-purity flexible graphite paper and a saturated calomel electrode (SCE) were used as a three-electrode system, using yield, interlayer spacing, and defect degree as evaluation criteria to explore the influence of electrolytic voltage and electrolyte concentration on graphite electrochemical exfoliation. Using dispersion state, settling time, and defect degree as evaluation criteria to examined the impact of dispersant type on the quality of graphene. The research demonstrated that electrochemical exfoliating at 10 V cell voltage with a bipolar distance of 2 cm in a 0.20 M Na 2 SO 4 solution at pH 7 and room temperature, followed by a 10 min ultrasound dispersion in a C 2 H 5 OH medium at a liquid–solid ratio of 1444:1. The efficiency of graphene production is 59.8%, with low defect levels ( I D / I G = 0.355), large interlayer spacing ( d = 0.350 nm), and a few layers (approximately 4 layers). In addition, the graphene dispersed in a N , N -Dimethylformamide (DMF) medium with a liquid–solid ratio of 1512:1 exhibits the highest level of stability.
研究领域:
材料科学
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电化学
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纳米技术
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
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IF 9.965
Ling Ouyang,Qiang Zhou,Jie Liang,Longcheng Zhang,Luchao Yue,Zerong Li,Jun Li,Yongsong Luo,Qian Liu,Na Li,Bo Tang,Abdulmohsen Ali Alshehri,Feng Gong,Xuping Sun
Electrocatalytic NO reduction is a promising technology for ambient NO removal with simultaneous production of highly value-added NH 3 . Herein, we report that honeycomb carbon nanofiber coated on carbon paper acts as an efficient metal-free catalyst for ambient electroreduction of NO to NH 3 . In 0.2 M Na 2 SO 4 solution, such catalyst achieves an NH 3 yield of 22.35 μmol h −1 cm −2 with a high Faradaic efficiency of up to 88.33%. Impressively, it also shows excellent stability for 10-h continuous electrolysis. Theoretical calculations reveal that the most active center of functional groups is –OH group for NO reduction with a low energy barrier (ΔG of 0.29 eV) for the potential-determining step (*NO + H → *HNO).
研究领域:
环境科学
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材料科学
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电化学
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催化
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
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2024
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IF 24.4
Gaojing Yang,Yaxun Zhu,Zhimeng Hao,Qiu Zhang,Yong Lu,Zhenhua Yan,Jun Chen
Redox flow batteries (RFBs) are considered as promising candidates for large-scale energy storage. However, traditional RFBs based on toxic metal ions have deficiencies in resource utilization and environmental protection. Considering the corrosiveness of acidic and alkaline electrolytes and sustainability of energy storage devices, neutral aqueous organic redox flow batteries (AORFBs) have more development prospects. Herein, an AORFB is reported, using 9,10-anthraquinone-2,7-disulfonic salt (2,7-AQDS) and 1,4-dihydroxyphenylsulfonate potassium (HQS) as negative and positive electroactive materials, respectively. It is found that the anions in the neutral solution further affected the solubility and kinetics of the electroactive materials by affecting the hydrogen bond in the solution, and the Na 2 SO 4 solution showed the optimal comprehensive performance. Therefore, an all-quinone AORFB employing neutral Na 2 SO 4 electrolytes with a cell voltage of 0.9 V is constructed, which presented a capacity utilization of 70.1% and delivered stable cycling performance at 60 mA cm −2 . This work designs an innovative neutral all-quinone AORFB and points out how anions affect the properties of the electrolyte by affecting hydrogen bonds within the solution. These findings open a new avenue for the design and application of neutral all-organic aqueous RFBs.
研究领域:
能源存储
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电化学
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材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）