Co-reporter:Li Jun Fang, Yu Hang Li, Peng Fei Liu, Dan Ping Wang, Hui Dan Zeng, Xue Lu WangHua Gui Yang
ACS Sustainable Chemistry & Engineering 2017 Volume 5(Issue 3) pp:
Publication Date(Web):February 1, 2017
DOI:10.1021/acssuschemeng.6b02721
Exfoliation of bulk graphitic carbon nitride (BCN) into two-dimensional (2D) nanosheets is one of the effective strategies to improve its photocatalytic performance. Compared with BCN, the 2D g-C3N4 nanosheets (CNNS) have larger specific surface areas and more reaction sites. With the etching assistance of anhydrous ethylenediamine, BCN can be successfully peeled off into 2D CNNS with a large lateral size of more than 15 μm which is much larger than that of other works. After appropriate etch by anhydrous ethylenediamine, the specific surface area of g-C3N4 expands from 4.7 to 31.1 m2 g–1 and the photocatalytic hydrogen evolution rate increases 7.4 times, from 4.8 to 35.3 μmol h–1. In contrast to other reported methods, the strategy to fabricate 2D CNNS in this work is convenient and it is the first time to report the fabrication of 2D CNNS with the assistance of alkaline reagent.Keywords: Anhydrous ethylenediamine; Graphitic carbon nitride nanosheets; Hydrogen evolution; Liquid etching; Photocatalysis;
Co-reporter:Huidan Zeng, Feng Ye, Xiang Li, Ling Wang, Bin Yang, Jianding Chen, Xianghua Zhang, Luyi Sun
Chemical Physics Letters 2016 Volume 662() pp:268-272
Publication Date(Web):1 October 2016
DOI:10.1016/j.cplett.2016.09.001
Highlights
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The derived equation allows for the computation of TCT of glasses from degree of freedom. As presented in this paper, our approach has two advantages: it is empirical parameters-free compared with the early theoretical calculations, and this is a much more time and cost efficient method compared with molecular dynamic simulations.
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The constraint strength index introduced in the paper for calculation of degree of freedom of alkali silicate glasses is already verified to overcome the limitations of TCT, which ignored the influence of glass modifiers in early investigations.
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Results showed that the calculated values are favored in the experimental results and the strong linear relationship were displayed. It is believed that this work established a configuration-based methodology to calculate the thermal expansion coefficient of the materials, like glasses, which lack periodic order.
Co-reporter:Ying Chen, Shuang Yang, Xiao Chen, Yi Chu Zheng, Yu Hou, Yu Hang Li, Hui Dan Zeng and Hua Gui Yang
Journal of Materials Chemistry A 2015 vol. 3(Issue 31) pp:15854-15857
Publication Date(Web):02 Jul 2015
DOI:10.1039/C5TA03616J
Here we report a one-pot solvothermal approach to synthesize cuboid shaped CH3NH3PbI3 single crystals and study the stability of crystallographic planes in a solvothermal system. Furthermore, the dissolution phenomenon from specific facets was discovered for the first time. Through careful control of the crystallization and dissolution processes, we found that reaction factors including temperature and time play critical roles in the crystallization process of perovskite crystals.
Co-reporter:Zhaofeng Wang, Yezhou Li, Qi Jiang, Huidan Zeng, Zhipeng Ci and Luyi Sun
Journal of Materials Chemistry A 2014 vol. 2(Issue 22) pp:4495-4501
Publication Date(Web):05 Mar 2014
DOI:10.1039/C4TC00424H
In this work, Tm3+ and Yb3+ co-doped NaGd(WO4)2 nanoparticles were synthesized via surfactant-assisted hydrothermal reactions. The structural analysis indicates that Tm3+ and Yb3+ ions have been doped into the NaGd(WO4)2 host by occupying the Gd3+ sites. The as-prepared NaGd(WO4)2:Tm3+,Yb3+ nanomaterials are spherical particles of approximate sizes in the range 50–80 nm. The upconversion spectra results suggest that the NaGd(WO4)2:Tm3+,Yb3+ nanoparticles exhibit pure or virtually pure near-infrared to near-infrared upconversion luminescence when excited by a 975 nm laser. This phenomenon is significant for nanoparticles with applications in bio-imaging, because both excitations and emissions in the near-infrared region reduce the autofluorescence and light scattering from biological tissues. On the basis of the upconversion and Raman spectra, a possible mechanism for the high purity near-infrared upconversion emission is proposed. Moreover, the NaGd(WO4)2:Tm3+,Yb3+ nanoparticles also exhibit paramagnetism, which is promising for bio-separation applications.
Co-reporter:Huidan Zeng, Zhao Liu, Qi Jiang, Bo Li, Chao Yang, Zhengjun Shang, Jing Ren, Guorong Chen
Journal of the European Ceramic Society 2014 Volume 34(Issue 16) pp:4383-4388
Publication Date(Web):December 2014
DOI:10.1016/j.jeurceramsoc.2014.06.031
Homogeneous transparent optical glass–ceramics precipitated with unique nonlinear crystals are promising materials for photonic applications. We have utilized heat treatment method to prepare transparent ZnO–Bi2O3–B2O3 glass–ceramic containing Bi2ZnB2O7 nonlinear nanocrystals. A large third-order nonlinear susceptibility χ(3) of glass–ceramic is measured by Z-scan technique, which mainly attributed to unique [BiO6] and [B2O5] units in Bi2ZnB2O7 crystal structure and the quantum size effect of nanoparticles. The discovery is of great potential in the application of nonlinear optical integrated devices.
Co-reporter:Qing Yu, Huidan Zeng, Qi Jiang, Zhao Liu, Luyi Sun, Jing Ren, Guorong Chen
Journal of Non-Crystalline Solids 2014 Volume 383() pp:165-168
Publication Date(Web):1 January 2014
DOI:10.1016/j.jnoncrysol.2013.04.035
•LiZnPO4 nanocrystals are precipitated in glass matrix through heat treatments.•Mn2 + ions exist in glass matrix instead of LiZnPO4 crystal lattice.•Mn2 + doped GC with high transparency exhibit broad red emission (FWHM = 125 nm).•Mn2 + doped GC containing LiZnPO4 nanocrystals is potential for LED materials.Fabrication of Mn2 + doped Li2O–ZnO–P2O5 phosphate glass-ceramics with a broad red emission is reported in the present work. The influence of heat treatment process on the crystallization behavior and optical properties of glasses were investigated. The results indicated that LiZnPO4 crystals precipitated in glass matrix after proper heat treatment. Compared with the glass, the red emission intensity of Mn2 + activated glass-ceramics exhibited significant enhancement. However, there is no evidence showing that Mn2 + ions exist in the LiZnPO4 crystals.
Co-reporter:Huidan Zeng, Qi Jiang, Zhao Liu, Xiang Li, Jing Ren, Guorong Chen, Fude Liu, and Shou Peng
The Journal of Physical Chemistry B 2014 Volume 118(Issue 19) pp:5177-5183
Publication Date(Web):April 29, 2014
DOI:10.1021/jp5018357
Sodium phosphosilicate glasses exhibit unique properties with mixed network formers, and have various potential applications. However, proper understanding on the network structures and property-oriented methodology based on compositional changes are lacking. In this study, we have developed an extended topological constraint theory and applied it successfully to analyze the composition dependence of glass transition temperature (Tg) and hardness of sodium phosphosilicate glasses. It was found that the hardness and Tg of glasses do not always increase with the content of SiO2, and there exist maximum hardness and Tg at a certain content of SiO2. In particular, a unique glass (20Na2O–17SiO2–63P2O5) exhibits a low glass transition temperature (589 K) but still has relatively high hardness (4.42 GPa) mainly due to the high fraction of highly coordinated network former Si(6). Because of its convenient forming and manufacturing, such kind of phosphosilicate glasses has a lot of valuable applications in optical fibers, optical amplifiers, biomaterials, and fuel cells. Also, such methodology can be applied to other types of phosphosilicate glasses with similar structures.
Co-reporter:Ying Cao, Huidan Zeng, Fan Zhang, Yanglong Chen, Liu Hang, Zhihong Tang, Qi Jiang, Xianying Wang
Applied Surface Science 2012 Volume 263() pp:95-99
Publication Date(Web):15 December 2012
DOI:10.1016/j.apsusc.2012.09.005
Abstract
Oriented ZnO nanowire (NW) arrays were fabricated via hydrothermal method using TiOx films as the seeding layer. Structural and morphological analysis indicates that the TiOx seeding layer can greatly improve the crystallinity and alignments of ZnO NWs. The photoluminescence (PL) spectra of ZnO NWs grown on the 1 nm TiOx seed layer exhibit enhanced UV emission. Improved growth of ZnO NWs on TiOx seed layer may facilitate the fabrication of high performance dye sensitized solar cell devices.
Co-reporter:Huidan Zeng, Yifan Yang, Zhenyu Lin, Xiaoluan Liang, Shuanglong Yuan, Guorong Chen, Luyi Sun
Journal of Non-Crystalline Solids 2011 Volume 357(11–13) pp:2328-2331
Publication Date(Web):June 2011
DOI:10.1016/j.jnoncrysol.2010.11.093
A series of Eu ion-doped aluminoborosilicate glasses was prepared by melt-quenching method and characterized by spectroscopic techniques, including Fourier transform infrared (FTIR), absorption, photoluminescence (PL), and electron paramagnetic resonance (EPR). The FTIR spectra showed that various glass structures formed when Al2O3 was partially replaced by B2O3. The PL characterization revealed that the emission intensity of Eu2+ ions firstly increased and then decreased with an increasing amount of Al2O3 replaced by B2O3. Meanwhile, the emission intensity ratio of [Eu2+]/[Eu3+] also followed the same trend. The EPR spectra confirmed the concentration variation of Eu2+ ions in the glass samples, which agreed well with the PL results. The possible mechanism of the effect of the glass network structure on the reduction behavior of Eu ions is discussed.
Co-reporter:Huidan Zeng, Zhenyu Lin, Qiang Zhang, Danping Chen, Xiaoluan Liang, Yinsheng Xu, Guorong Chen
Materials Research Bulletin 2011 46(2) pp: 319-322
Publication Date(Web):
DOI:10.1016/j.materresbull.2010.09.002
Co-reporter:Huidan Zeng, Jianrong Qiu, Shuanglong Yuan, Yunxia Yang, Guorong Chen
Ceramics International 2008 Volume 34(Issue 3) pp:605-608
Publication Date(Web):April 2008
DOI:10.1016/j.ceramint.2006.12.011
Abstract
Precipitation behaviors of metallic nanoparticles inside silicate glasses by femtosecond laser irradiation are studied in this work. Laser irradiation results easily in precipitation of metallic nanoparticles where colors depend in part on their sizes and quantities. Laser irradiation induced precipitation of metallic nanoparticles displays the different behaviors from that in the unirradiated area inside glasses and their mechanisms are investigated.
Co-reporter:Huidan Zeng, Guorong Chen, Jianrong Qiu, Xiongwei Jiang, Congshan Zhu, Fuxi Gan
Journal of Non-Crystalline Solids 2008 Volume 354(12–13) pp:1155-1158
Publication Date(Web):15 February 2008
DOI:10.1016/j.jnoncrysol.2006.11.046
We report on three-dimensional precipitation of Au nanoparticles in gold ions-doped silicate glasses by a femtosecond laser irradiation and further annealing. Experimental results show that PbO addition plays the double roles of inhibiting hole-trapped centers generation and promoting formation and growth of gold nanoparticles. Additionally, glass containing PbO shows an increased non-linear absorption after femtosecond laser irradiation and annealing. The observed phenomena are significant for applications such as fabrications of three-dimensional multi-colored images inside transparent materials and three-dimensional optical memory, and integrated micro-optical switches.
Co-reporter:Xiang Li, Huidan Zeng, Qi Jiang, Donghui Zhao, Guorong Chen, Zhaofeng Wang, Luyi Sun, Jianding Chen
Physica B: Condensed Matter (1 December 2016) Volume 502() pp:88-92
Publication Date(Web):1 December 2016
DOI:10.1016/j.physb.2016.08.030
In recent years, composition-dependent properties of glasses have been successfully predicted using the topological constraint theory. The constraints of the glass network are derived from two main parts: network formers and network modifiers. The constraints of the network formers can be calculated on the basis of the topological structure of the glass. However, the latter cannot be accurately calculated in this way, because of the existing of ionic bonds. In this paper, the constraints of the modifier ions in phosphate glasses were thoroughly investigated using the topological constraint theory. The results show that the constraints of the modifier ions are gradually increased with the addition of alkali oxides. Furthermore, an improved topological constraint theory for borophosphate glasses is proposed by taking the composition-dependent constraints of the network modifiers into consideration. The proposed theory is subsequently evaluated by analyzing the composition dependence of the glass transition temperature in alkali borophosphate glasses. This method is supposed to be extended to other similar glass systems containing alkali ions.
Co-reporter:Ying Chen, Shuang Yang, Xiao Chen, Yi Chu Zheng, Yu Hou, Yu Hang Li, Hui Dan Zeng and Hua Gui Yang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 31) pp:NaN15857-15857
Publication Date(Web):2015/07/02
DOI:10.1039/C5TA03616J
Here we report a one-pot solvothermal approach to synthesize cuboid shaped CH3NH3PbI3 single crystals and study the stability of crystallographic planes in a solvothermal system. Furthermore, the dissolution phenomenon from specific facets was discovered for the first time. Through careful control of the crystallization and dissolution processes, we found that reaction factors including temperature and time play critical roles in the crystallization process of perovskite crystals.
Co-reporter:Zhaofeng Wang, Yezhou Li, Qi Jiang, Huidan Zeng, Zhipeng Ci and Luyi Sun
Journal of Materials Chemistry A 2014 - vol. 2(Issue 22) pp:NaN4501-4501
Publication Date(Web):2014/03/05
DOI:10.1039/C4TC00424H
In this work, Tm3+ and Yb3+ co-doped NaGd(WO4)2 nanoparticles were synthesized via surfactant-assisted hydrothermal reactions. The structural analysis indicates that Tm3+ and Yb3+ ions have been doped into the NaGd(WO4)2 host by occupying the Gd3+ sites. The as-prepared NaGd(WO4)2:Tm3+,Yb3+ nanomaterials are spherical particles of approximate sizes in the range 50–80 nm. The upconversion spectra results suggest that the NaGd(WO4)2:Tm3+,Yb3+ nanoparticles exhibit pure or virtually pure near-infrared to near-infrared upconversion luminescence when excited by a 975 nm laser. This phenomenon is significant for nanoparticles with applications in bio-imaging, because both excitations and emissions in the near-infrared region reduce the autofluorescence and light scattering from biological tissues. On the basis of the upconversion and Raman spectra, a possible mechanism for the high purity near-infrared upconversion emission is proposed. Moreover, the NaGd(WO4)2:Tm3+,Yb3+ nanoparticles also exhibit paramagnetism, which is promising for bio-separation applications.
