Anhui Normal University

About: Anhui Normal University is a education organization based out in Wuhu, China. It is known for research contribution in the topics: Catalysis & Population. The organization has 7955 authors who have published 7309 publications receiving 117443 citations.

Van der Waals trilayers and superlattices: Modification of electronic structures of MoS2 by intercalation

Abstract: We perform a comprehensive first-principles study of the electronic properties of van der Waals (vdW) trilayers via intercalating a two-dimensional (2D) monolayer (ML = BN, MoSe2, WS2, or WSe2) between MoS2 bilayer to form various MoS2/ML/MoS2 sandwich trilayers. We find that the BN monolayer is the most effective sheet to decouple the interlayer vdW coupling of the MoS2 bilayer, and the resulting sandwich trilayer can recover the electronic structures of the MoS2 monolayer, particularly the direct-gap character. Further study of the MoS2/BN superlattices confirms the effectiveness of the BN monolayer for the decoupling of the MoS2-MoS2 interaction. In addition, the intercalation of transition-metal dichalcogenide (TMDC) MoSe2 or WSe2 sheet renders the sandwich trilayer undergoing an indirect-gap to direct-gap transition due to the newly formed heterogeneous S/Se interfaces. In contrast, the MoS2/WS2/MoS2 sandwich trilayer still retains the indirect-gap character of the MoS2 bilayer due to the lack of the heterogeneous S/Se interfaces. Moreover, the 3D superlattice of the MoS2/TMDC heterostructures also exhibits similar electronic band characters as the MoS2/TMDC/MoS2 trilayer heterostructures, albeit slight decrease of the bandgap than the trilayers. Compared to the bulk MoS2, the 3D MoS2/TMDC superlattice can give rise to new and distinctive properties. Our study offers not only new insights into electronic properties of the vdW multilayer heterostructures but also guidance in designing new heterostructures to modify electronic structures of 2D TMDC crystals.

Syntheses and photophysical properties of BF2 complexes of curcumin analogues.

Abstract: Stable tetracoordinated organoboron complexes as classic fluorescent molecules have found various applications in material and medical sciences. A new class of curcumin-BF2 complexes has been prepared from the condensation of 2,2-difluoro-1,3-dioxaborylpentadione with a variety of aldehydes and its photophysical properties were characterized. Systematic variations were observed in the absorption spectra of these curcumin-BF2 dyes in solutions, which are well correlated with their structural features, including characteristics of the aromatic groups and presence of a para electron-donating substituent. Strong fluorescence that is tunable from 500 to 800 nm via variation of the polarity of the solvent and a moderate to good fluorescence quantum yield ranging from 0.24 to 0.58 in dichloromethane were observed in curcumin-BF2 complexes 1. By contrast, their asymmetrical analogue, curcumin-BF2 complexes 3 exhibit much lower fluorescence quantum yields. Besides their excellent photostabilities, these curcumin-BF2 dyes also show singlet oxygen generating capabilities.

Hierarchical NiMn2O4@CNT nanocomposites for high-performance asymmetric supercapacitors

Abstract: Miniaturized energy storage devices have attracted considerable research attention due to their promising applications in various smart electronic devices. In this work, a high performance asymmetric supercapacitor (ASC) device was designed and fabricated wherein a novel nanocomposite consisting of manganese oxide (NiMn2O4) nanosheets with carbon nanotubes (CNTs) was used as the active material. High capacitance of 151 F g−1 and energy density of 60.69 W h kg−1 were achieved for the CNT@NiMn2O4 nanocomposites ASC at a current density of 1 A g−1, which attributing to the widen operation voltage window ranging from 0 to 1.7 V. Moreover, the CNT@NiMn2O4 nanocomposites ASC also showed remarkable cycling stability with 96.3% energy density retention after 5000 cycles. As a result, the CNT@NiMn2O4 nanocomposite is a possible contender materials for next generation supercapacitors in high energy density storage systems.

Projected streamflow in the Huaihe River Basin (2010-2100) using artificial neural network

Abstract: Climate projections for the Huaihe River Basin, China, for the years 2001–2100 are derived from the ECHAM5/MPI-OM model based on observed precipitation and temperature data covering 1964–2007. Streamflow for the Huaihe River under three emission scenarios (SRES-A2, A1B, B1) from 2010 to 2100 is then projected by applying artificial neural networks (ANN). The results show that annual streamflow will change significantly under the three scenarios from 2010 to 2100. The interannual fluctuations cover a significant increasing streamflow trend under the SRES-A2 scenario (2051–2085). The streamflow trend declines gradually under the SRES-A1B scenario (2024–2037), and shows no obvious trend under the SRES-B1 scenario. From 2010 to 2100, the correlation coefficient between the observed and modeled streamflow in SRES-A2 scenario is the best of the three scenarios. Combining SRES-A2 scenario of the ECHAM5 model and ANN might therefore be the best approach for assessing and projecting future water resources in the Huaihe basin and other catchments. Compared to the observed period of streamflows, the projected periodicity of streamflows shows significant changes under different emission scenarios. Under A2 scenario and A1B scenario, the period would delay to about 32–33a and 27–28a, respectively, but under B1 scenario, the period would not change, as it is about 5–6a and the observed period is about 7–8a. All this might affect drought/flood management, water supply and irrigation projects in the Huaihe River basin.