JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Zhengjiong Li,Haonan Peng,Rurong Liu,Yan Mo,Bokai Cao,Wende Lai,Xiran Li,Lisha Pan,Yong Chen
Activated carbon is widely used as electrode materials in supercapacitors , and its capacitive performance is significantly influenced by the specific surface area. However, different types of wall surfaces, such as basal-, edge- and defect-surfaces, exist in carbonaceous materials due to the complex structure and atomic distribution of carbon atoms, rendering different influences on capacitive charge storage behavior. Therefore, it is of utmost significance to quantitatively determine their contribution to the capacitive performance. Herein, the commercial graphite powder is ball milled to introduce different types of edges and defects, resulting in different proportions of basal-, edge- and defect-surfaces. Moreover, a modified non-local density functional theory calculations method is adopted to quantitatively evaluate the basal-, edge- and defect-surface area. Then, a relationship is established between the electrode capacitance and wall surface area by the linear regression method. The results reveal that the basal-, edge- and defect-surfaces contributed an areal capacitance of 0.04 μF cm −2 , 1.65 μF cm −2 and 7.95 μF cm −2 , respectively. Hence, the capacitance is mainly provided by the defects of wall surfaces.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Yuxin Chen,Shuairen Qian,Kai Feng,Zhengwen Li,Binhang Yan,Yi Cheng
The original phase-pure M1 MoVNbTeO x catalyst was mechanically treated with stirring water for several days under ambient conditions to obtain particles with different sizes. The catalytic performance was significantly improved and stabilized after about 7 days of treatment. Among all the catalysts, the sample treated in water for 7 days can obtain 57.6 % ethane conversion and 0.79 kg C2H4 /kg cat /h ethylene productivity while the original phase-pure M1 catalyst was only 19.2 % and 0.27 kg C2H4 /kg cat /h at reaction temperature of 400 °C and contact time of 18.5 g cat ·h/mol C2H6 . Meanwhile, the catalyst was systematically characterized and the results showed that there was essentially no difference in microstructure between the original and treated catalysts. TEM and SEM morphological characterizations presented that the particle size and aspect ratio of the catalysts changed significantly, in which the particle size of the catalyst become smaller and the proportion of basal surface was enhanced. The activity and selectivity of the catalysts exhibited a correlation with the amount and proportion of basal surface. It can be deducted that the basal surface is the most active and selective surface during oxidative dehydrogenation of ethane (ODHE) process, and the intrinsic activity based on the basal (0 0 1) plane of the catalyst remains stable after the mechanical treatment. Samples treated in water for 7 days showed excellent long-term stability in a 200 h stability test at reaction temperature of 440 °C and contact time of 9.3 g cat ·h/mol C2H6 . The present work demonstrated that the differences in the catalytic properties of different M1 samples depend mainly on the amount and proportion of exposed basal surface, and the possibility of enhancing the activity of orthorhombic M1 phase by fragmentation method.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Yanei Xue,Penghui Shao,Yixing Yuan,Wenxin Shi,Fuyi Cui
The 2H phases of MoS2 (2H-MoS2) monolayers present a wealth of new opportunities in photocatalysis owing to their photoinduced catalyzing ability and excellent charge carrier mobility. However, the complete release of their catalytic activities is restricted by their inert basal planes. Although the inert base planes of 2H-MoS2 are known to be activated by atomic doping, the operational principle of the exotic atoms remains vague. In this study, the unutilized inert base sites of MoS2 were activated via an oxygen-aided P-substituted method (denoted as POMS). Molecular structural tests and analyses of POMS indicated that the inert MoS2 substrate is activated when the inerratic crystal phases transform to amorphous phases in the P-doping process. The fully activated inert base planes provide sufficient reaction sites for photo-oxidized water contaminants. The designed POMS presented superior activity in organic degradation and completely removed sulfamethoxazole within 20 min. Uncovering these operational principles provides a theoretical basis for designing effective catalysts.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2018
·Vol. 24
·期 71
·19075-19080
·
IF 5.16
Shuo Geng,Hu Liu,Weiwei Yang,Yong Sheng Yu
Graphical Go nano ! Porous MoS 2 nanosheets were synthesized by etching away Al in Al-doped MoS 2 . The optimized porous MoS 2 nanosheets show a better hydrogen evolution reaction (HER) activity owing to the activated basal plane (see figure). Molybdenum disulfide has drawn persistent interest as a promising nonprecious electrocatalyst alternative to Pt for the hydrogen evolution reaction (HER). However, the MoS 2 catalytic efficiency is still lower than the Pt-based catalysts owing to insufficient active sites with more inert basal planes. Herein, we designed and synthesized porous MoS 2 nanosheets to activate the basal planes by etching away Al in Al-doped MoS 2 . The optimized porous MoS 2 shows a small onset overpotential as low as 136 mV, a large cathode current density of 10 mA cm −2 at η =201 mV, a low Tafel slope of 62 mV decade −1 , and a high TOF of 0.29 H 2 s −1 per active site at η =200 mV. This study opens up new avenues for designing electrocatalysts based on porous MoS 2 or other layered materials with enhanced HER performance.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
MINERALS ENGINEERING
·
2025
·
IF 5
Jiaozhong Cai,Shuiping Zhong,Jiushuai Deng,Bozeng Wu,Chengyan Xu,Xiaopeng Chi,Guangsheng Zeng,Wei Weng,Wen Tan,Junnan Chen
Talc is a layered silicate mineral with pronounced crystal anisotropy, consisting of a basal (001) surface and an edge (100) surface, which complicates its separation from valuable minerals. In this study, tannic acid (TA) was used as a depressant, and its adsorption behaviors on the two representative surfaces of talc—silica (basal plane surface) and magnesium silicate (edge surface)—were systematically investigated using experimental methods and molecular simulations. TA addition reduced the contact angles of the talc basal and edge surfaces by 30.5° and 22.7°, respectively, indicating enhanced hydrophilicity. ToF-SIMS analysis revealed that TA physically adsorbs onto the silica surface, while both physical and chemical interactions occur on the magnesium silicate surface. AFM showed lumpy adsorbate on the silica surface and point-like adsorbate on the magnesium silicate surface, with a greater roughness change observed for the former. QCM-D measurements confirmed that TA formed a multilayer flexible adsorbate on the silica surface and a dense, rigid monolayer on the magnesium silicate surface. Molecular dynamics simulations further revealed that van der Waals interactions dominated TA adsorption on the (001) surface, while electrostatic interactions prevailed on the (100) surface. These findings provide insight into the selective depression mechanism of talc and offer guidance for the depression of other layered silicate minerals.
研究领域:
矿物加工
·
表面化学
·
分子模拟
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Lei Liu,Ning Liu,Chengna Dai,Ruinian Xu,Gangqiang Yu,Ning Wang,Biaohua Chen
Realizing MoS2 basal plane activation is highly desirable and challenging in the field of hydrodesulfurization (HDS). Herein, we have developed a new strategy of dual Co single atom doping (SAD) combined with CO in situ regulation, which can successfully activate the basal plane of Co3.6%–MoS2-0.3 generating high ratios of thermostable 1T-plane (∼70%) and large S vacancies. For the first time, a synergistic effect has been unraveled where the lattice substituted neighboring dual SA Co can efficiently activate in-plane S through extensively reducing its band gap (2.21 → 0.14 eV), which tremendously favors S subtraction and 2H → 1T phase transition assisted by CO. Boosted thiophene HDS activity can be eventually achieved with the reaction rate constant (k) being 8.3 times higher than that of commercial cCo3.6%–MoS2 (0.04 → 0.33 h–1). Generally, the present work paves a new way for next-generation HDS catalyst design with activated basal plane.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 31
·期 38
·2103569
·
IF 18.808
Yu Li,Gao Chen,Yanping Zhu,Zhiwei Hu,Ting-Shan Chan,Sixuan She,Jie Dai,Wei Zhou,Zongping Shao
Layered A x CoO 2 materials built by stacking layers of CoO 2 slabs and inserting alkali ions in between them have shown a promising activity of oxygen evolution reaction (OER) due to their active edge sites. However, the large basal plane areas of the CoO 2 slabs show too strong adsorption energy to the reaction intermediates, which is unfavorable for the release of O 2 . Here, a simple cation-exchange strategy based on Fe 3+ and alkali ions is proposed to simultaneously activate both the basal plane and edge sites of A x CoO 2 for the OER. X-ray absorption spectroscopy has revealed that the Fe 3+ ions deposit both on the surface and edge sites of the CoO 2 slabs and enter the interlayer. The cation-exchanged A x CoO 2 electrodes show a boosted activity compared to their pristine and conventional Fe-doped A x CoO 2 counterparts. This phenomenon is mainly ascribed to the abundant edge-sharing Co–Fe motifs at the edge sites and the charge redistribution in the basal plane sites induced by the insertion of Fe 3+ ions. This work provides a novel method to fully exploit layer-structured materials for efficient energy conversion.
研究领域:
材料化学
·
电催化
·
能源转换
·
无机化学
·
表面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）