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Author Cheng, X.; Xu, W.; Wen, H.; Zhang, J.; Zhang, H.; Li, H.; Peeters, F.M.; Chen, Q.
Title Electronic properties of 2H-stacking bilayer MoS₂ measured by terahertz time-domain spectroscopy Type A1 Journal article
Year (down) 2023 Publication Frontiers of physics Abbreviated Journal
Volume 18 Issue 5 Pages 53303-53311
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Bilayer (BL) molybdenum disulfide (MoS2) is one of the most important electronic structures not only in valleytronics but also in realizing twistronic systems on the basis of the topological mosaics in moire superlattices. In this work, BL MoS2 on sapphire substrate with 2H-stacking structure is fabricated. We apply the terahertz (THz) time-domain spectroscopy (TDS) for examining the basic optoelectronic properties of this kind of BL MoS2. The optical conductivity of BL MoS2 is obtained in temperature regime from 80 K to 280 K. Through fitting the experimental data with the theoretical formula, the key sample parameters of BL MoS2 can be determined, such as the electron density, the electronic relaxation time and the electronic localization factor. The temperature dependence of these parameters is examined and analyzed. We find that, similar to monolayer (ML) MoS2, BL MoS2 with 2H-stacking can respond strongly to THz radiation field and show semiconductor-like optoelectronic features. The theoretical calculations using density functional theory (DFT) can help us to further understand why the THz optoelectronic properties of BL MoS2 differ from those observed for ML MoS2. The results obtained from this study indicate that the THz TDS can be applied suitably to study the optoelectronic properties of BL MoS2 based twistronic systems for novel applications as optical and optoelectronic materials and devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000991955300002 Publication Date 2023-05-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2095-0462; 2095-0470 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.5 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 7.5; 2023 IF: 2.579
Call Number UA @ admin @ c:irua:197398 Serial 8818
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Author Lu, Y.; Liu, X.-L.; He, L.; Zhang, Y.-X.; Hu, Z.-Y.; Tian, G.; Cheng, X.; Wu, S.-M.; Li, Y.-Z.; Yang, X.-H.; Wang, L.-Y.; Liu, J.-W.; Janiak, C.; Chang, G.-G.; Li, W.-H.; Van Tendeloo, G.; Yang, X.-Y.; Su, B.-L.
Title Spatial heterojunction in nanostructured TiO₂ and its cascade effect for efficient photocatalysis Type A1 Journal article
Year (down) 2020 Publication Nano Letters Abbreviated Journal Nano Lett
Volume 20 Issue 5 Pages 3122-3129
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A highly efficient photoenergy conversion is strongly dependent on the cumulative cascade efficiency of the photogenerated carriers. Spatial heterojunctions are critical to directed charge transfer and, thus, attractive but still a challenge. Here, a spatially ternary titanium-defected TiO2@carbon quantum dots@reduced graphene oxide (denoted as V-Ti@CQDs@rGO) in one system is shown to demonstrate a cascade effect of charges and significant performances regarding the photocurrent, the apparent quantum yield, and photocatalysis such as H-2 production from water splitting and CO2 reduction. A key aspect in the construction is the technologically irrational junction of Ti-vacancies and nanocarbons for the spatially inside-out heterojunction. The new “spatial heterojunctions” concept, characteristics, mechanism, and extension are proposed at an atomic- nanoscale to clarify the generation of rational heterojunctions as well as the cascade electron transfer.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000535255300024 Publication Date 2020-04-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 10.8 Times cited 5 Open Access Not_Open_Access
Notes ; This work was supported by the joint National Natural Science Foundation of China-Deutsche Forschungsgemeinschaft (NSFC-DFG) project (NSFC grant 51861135313, DFG JA466/39-1), Fundamental Research Funds for the Central Universities (19lgpy113, 19lgzd16), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52) and Jilin Province Science and Technology Development Plan (20180101208JC). ; Approved Most recent IF: 10.8; 2020 IF: 12.712
Call Number UA @ admin @ c:irua:170263 Serial 6608
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Author Lu, Y.; Cheng, X.; Tian, G.; Zhao, H.; He, L.; Hu, J.; Wu, S.-M.; Dong, Y.; Chang, G.-G.; Lenaerts, S.; Siffert, S.; Van Tendeloo, G.; Li, Z.-F.; Xu, L.-L.; Yang, X.-Y.; Su, B.-L.
Title Hierarchical CdS/m-TiO 2 /G ternary photocatalyst for highly active visible light-induced hydrogen production from water splitting with high stability Type A1 Journal article
Year (down) 2018 Publication Nano energy Abbreviated Journal Nano Energy
Volume 47 Issue Pages 8-17
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Abstract Hierarchical semiconductors are the most important photocatalysts, especially for visible light-induced hydrogen production from water splitting. We demonstrate herein a hierarchical electrostatic assembly approach to hierarchical CdS/m-TiO2/G ternary photocatalyst, which exhibits high photoactivity and excellent photostability (more than twice the activity of pure CdS while 82% of initial photoactivity remained after 15 recycles during 80 h irradiation). The ternary nanojunction effect of the photocatalyst has been investigated from orbitals hybrid, bonding energy to atom-stress distortion and nano-interface fusion. And a coherent separation mechanism of charge carriers in the ternary system has been proposed at an atomic/nanoscale. This work offers a promising way to inhibit the photocorrosion of CdS and, more importantly, provide new insights for the design of ternary nanostructured photocatalysts with an ideal heterojunction.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000430057000002 Publication Date 2018-02-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2211-2855 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.343 Times cited 58 Open Access Not_Open_Access
Notes This work supported by National Key R&D Program of China (2017YFC1103800), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52), National Natural Science Foundation of China (U1663225, U1662134, 51472190, 51611530672, 21711530705, 51503166, 51602236, 21706199), International Science & Technology Cooperation Program of China (2015DFE52870), Natural Science Foundation of Hubei Province (2016CFA033, 2017CFB487), Open 22 Project Program of State Key Laboratory of Petroleum Pollution Control (PPC2016007) CNPC Research Institute of Safety and Environmental Technology., China Postdoctoral Science Foundation (2016M592400), Fundamental Research Funds for the Central Universities (WUT: 2017IVB012). Approved Most recent IF: 12.343
Call Number EMAT @ lucian @c:irua:150720 Serial 4925
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Author Liu, S.; Wei, M.; Sui, X.; Cheng, X.; Cool, P.; Van Tendeloo, G.
Title A scanning electron microscopy study on hollow silica microspheres: defects and influences of the synthesis composition Type A1 Journal article
Year (down) 2009 Publication Journal of sol-gel science and technology Abbreviated Journal J Sol-Gel Sci Techn
Volume 49 Issue 3 Pages 373-379
Keywords A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Electron microscopy for materials research (EMAT)
Abstract Defects on hollow silica spheres synthesized in a tetraethylorthosilicate-octylamine-HCl-H2O system were recorded by scanning microscope. Based on the results, influences of synthesis composition on the formation of these defects are discussed. It is evidenced that products prepared with different octylamine-to-tetraethylorthosilicate ratios may have surface depressions, cracks and non-hollow microspheres. However, by changing water and acid additions, these defects could be reduced or eliminated. Generally, samples synthesized with a large octylamine addition commonly exhibit surface depressions. A small octylamine or a large water addition benefits the formation of solid silica microspheres among the product. Acid, although is not indispensable for the formation of hollow spheres, helps to eliminate or reduce depressions on the hollow shells. It is explained that the added acid gives rise to a relative localized fast hydrolysis versus condensation, facilitating an easy mobility of hydrolyzed silica species, and consequently the shell surface is smoothened.
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Corporate Author Thesis
Publisher Kluwer Place of Publication Dordrecht Editor
Language Wos 000263260100015 Publication Date 2008-12-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0928-0707;1573-4846; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.575 Times cited 1 Open Access
Notes Approved Most recent IF: 1.575; 2009 IF: 1.393
Call Number UA @ lucian @ c:irua:74962 Serial 2941
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Author Liu, S.; Rao, J.; Sui, X.; Cool, P.; Vansant, E.F.; Van Tendeloo, G.; Cheng, X.
Title Preparation of hollow silica spheres with different mesostructures Type A1 Journal article
Year (down) 2008 Publication Journal of non-crystalline solids Abbreviated Journal J Non-Cryst Solids
Volume 354 Issue 10/11 Pages 826-830
Keywords A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Electron microscopy for materials research (EMAT)
Abstract Hollow silica spheres were quickly synthesized by an octylamine (OA) templating method using tetraethyl orthosilicate (TEOS) as the silica source. N2-sorption results indicate that the hollow spheres have high surface areas and pore volumes. XRD and TEM measurements reveal that the structure of the hollow spheres depends on the amount of TEOS used in the synthesis. When low amount of TEOS is added, the template-containing precursor spheres depict an XRD pattern with two peaks, which can be indexed to a lamellar phase. After the removal of the template, the obtained hollow spheres show no diffraction peaks in the XRD pattern, suggesting that the nanopores in the silica shells are disordered. If increasing the amount of TEOS, either the uncalcined or the calcined sample gives an XRD pattern with a single diffraction peak. The mesostructure of these hollow silica spheres is typically as HMS materials. TGA analyses suggest that the interaction between the silica species and surfactant is stronger in the latter case.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000253216700003 Publication Date 2007-09-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3093; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.124 Times cited 26 Open Access
Notes Gao Approved Most recent IF: 2.124; 2008 IF: 1.449
Call Number UA @ lucian @ c:irua:72018 Serial 2703
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