RUSSIAN JOURNAL OF GENERAL CHEMISTRY
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2016
·Vol. 86
·期 7
·1747-1752
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IF 0.481
Lin Meijuan,Tang Qiang,Zeng Huijuan,Xing Guang,Ling Qidan
Several new Ir(III) complexes with 2-(4-bromophenyl)-1 H -benzo[d]imidazole or 2-(4-bromophenyl)- 1-methyl-benzo[ d ]imidazole ligands as cylcometalated ligand and acetylacetonate or picolinate as the ancillary ligand were synthesized and their structures and photophysical properties were characterized. HOMO and LUMO energy levels and the molecular structures of Ir(III) complexes were scrutinized by DFT calculations. The complexes exhibited green luminescence at the maximum emission peaks at ca 495–522 nm. The methyl group substituent and replacing of acetylacetonate with picolinate complex can enhance the complex thermal stability. HOMO energy levels of the complexes vary from –4.99 to –5.44 eV, the LUMO energy levels are between –1.52 and –1.97 eV.
研究领域:
材料科学
·
化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 47
·22335-22343
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IF 3.591
Siqi Wei,Haoyi Li,Xinghang Yin,Qiang Yang,Anli Chen,Renjie Li,Jing Wang,Rui Yang
Synthesizing high-efficiency red carbon dots (R-CDs) and exploring their photoluminescence mechanism remain challenges as well as critical issues hindering the development of red room-temperature phosphorescence (RTP) materials of CDs. Herein, a series of highly efficient R-CDs are prepared from citric acid and formamide by solvothermal method on account of the protective and destructive effects of solvents. The larger sp2 conjugated domains of the carbon core and the high content of graphitic N are identified as the key factors for R-CDs to exhibit red fluorescence. Surface groups also contribute to red emission by means of the formation of the N, O-related defect state. By establishing N-doping models and using DFT calculation, it is further demonstrated that the strong p–π conjugation effect caused by the non-bonding electrons of graphitic N would facilitate HOMO–LUMO splitting of the carbon core, thus leading to a significant decrease in the HOMO–LUMO gap. Energy level splitting could lead to a certain degree of energy level crossing, which could contribute to effective intersystem crossing and produce red RTP. From this, the potential applications of R-CDs in the information encryption field are proposed and demonstrated.
研究领域:
材料科学
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光电技术
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纳米技术
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化学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 47
·16623-16630
·
IF 6.4
Zhicheng Li,Yu Zhang,Zhongbin Pan,Xu Fan,Hao Wang,Peng Li,Haiming Huang,Weiliang Wang,Jinjun Liu,Jiwei Zhai
Flexible dielectric and electronic materials are widely employed in emerging fields. Dielectric energy storage technologies and materials are needed to simultaneously cope with stringent requirements, such as high-stability and compact-size energy storage. Nonetheless, many mainstream polymer dielectrics prematurely fail under the coupling of rising electric field strength and space charge accumulation. Herein, we constructed a one-dimensional core–shell heterogeneous filler (BiFeO3@Al2O3) and added it to wide HOMO–LUMO gap cyanoethyl cellulose, achieving ultrahigh breakdown strength (∼801 MV m−1) and dielectric constant (∼17.3), thus obtaining a substantial discharged energy density of ∼31.3 J cm−3, accompanied by stabilized cyclic charge/discharge of 105. The superior energy storage performance is ascribed to the shell (Al2O3) having a higher work function, forming built-in electric fields with core (BiFeO3), simultaneously decreasing the density of state and increasing the bandgap of nanofibers. This research provides an optimization technique for crafting advanced polymer dielectrics, catering to the evolving demands of modern energy storage applications.
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高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Huanhuan Sun,Hongyan Yu,Boyang Han,Junjie Ma,Rensheng Wang,Yanping Song
Pressure-induced surface-enhanced Raman spectroscopy (PI-SERS) is among the foremost achievements of high-pressure fields, benefiting from the advantage that pressure-modulated interactions between substrates and molecules overcome the weakness of individual substrates or molecules. However, the pressure corresponding to PI-SERS enhancement is currently still at a low-pressure stage within 8 GPa. Therefore, how to realize PI-SERS enhancement under higher or ultrahigh pressure remains a huge challenge. Here, we applied few-layer WS2 (FL-WS2) nanosheets as PI-SERS substrates and selected 4-mercaptobenzoic acid (4-MBA) molecules with a big energy gap as probes to explore PI-SERS enhancement in more depth. The experimental results indicate that the PI-SERS signals increase gradually as pressure increases and reaches a maximum at 18 GPa, which has set a pressure record for the PI-SERS field so far. Different from the C exciton resonance-induced SERS intensities at ambient conditions, the charge-transfer transition between FL-WS2 and 4-MBA is strengthened via the pressure-induced increase in the band gap of FL-WS2 and decrease in the highest-occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) energy gap of 4-MBA, thus enhancing PI-SERS signals accordingly. Therefore, this strategy will be beneficial for practical applications in the field of optoelectronics and for the design of other PI-SERS sensors for trace detection in complex and extreme environments.
研究领域:
材料科学
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纳米技术
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光电子学
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光谱学
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DOI
高影响因子
Energy Storage Materials
·
2023
·
IF 20.4
Xin Ren,Donggang Tao,Shuai Cui,Ting Li,Yuliang Cao,Fei Xu
Rechargeable Mg batteries are advantageous substitutes for lithium-ion batteries in large-scale energy storage with low cost and high safety, but the lack of cathode materials is blocking the development. Organic polymers are promising Mg-storage materials, and the construction of suitable Mg-storage active sites is of great significance for the performance. In the present study, a double-chain conjugated carbonyl polymer is designed and investigated as cathode material of rechargeable Mg batteries. The double-chain structure builds favorable active sites for reversible storage of bivalent Mg 2+ cation by means of immobilization of the two adjacent carbonyls. This double-chain polymer shows a higher Mg-storage capacity (194 mAg –1 ) than the corresponding single-chain polymer (116 mAg –1 ). The Mg-storage capacity of this double-chain polymer also exceeds the Li-storage capacity (106 mAg –1 ) significantly. A mechanism study demonstrates the reversible carbonyl enolization in Mg-storage reactions. A theoretical computation demonstrates the magnesiation structure has a higher HOMO and a lower LUMO energy level, as well as a smaller HOMO–LUMO gap. This is favorable for the Mg-storage reaction reversibility and stability of the magnesiation structure, thus improving the capacities and cycling stabilities. The principle revealed in the present study provides an important insight to design organic conjugated polymers with favorable Mg-storage active sites, which would assist the development of high-performance Mg-storage materials.
研究领域:
材料科学
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储能
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电化学
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聚合物化学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Youhua Xiao,Ruifeng Hu,Jiahao Li,Jingwen Ni,Xiao Yu,Xiaodong Lu,Xingyu Shang,Jie Mao,Shengxiang Yang
Dielectric elastomer (DE) materials hold promise as artificial muscles due to their ability to deform under external electric field stimulation. To enhance their actuation performance, we have improved the dielectric breakdown strength of polyurethane (PU) based DE materials by incorporating voltage stabilizers into their hard segment through copolymerization. Voltage stabilizers with a lower HOMO-LUMO energy gap can effectively capture high-energy electrons, thereby mitigating the degradation of polymer molecular chains and increasing the dielectric breakdown strength. Specifically, when 50 % of the hard segments in PU contain a kind of voltage stabilizer (4,4′-dihydroxybenzophenone, DHBP), the PU exhibits the optimized dielectric breakdown strength, increasing from an initial value of 32 V /μm to 58 V/μm. Notably, the modified PU retains a low initial modulus (0.24 MPa) without experiencing the stiffening problem, as the rigid structure of the DHBP is incorporated into the hard segments of PU. Without pre-stretching, the 50 % DHBP-PU achieves an improved maximum actuation strain of 57 % and a theoretical energy density of 14.4 J/m 3 at 83 V /μm, outperforming most PU-DE materials. The DHBP-PU, characterized by its enhanced dielectric breakdown strength and improved electroactuation performance, holds great potential for applications in flexible actuators and soft robotics.
研究领域:
材料科学
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高分子科学
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机电系统
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软体机器人
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产品关联
DOI
高影响因子
Advanced Energy and Sustainability Research
·
2024
·
IF 6.2
Hong Tu,Ying Xu,Shun-shun Chen,Ya Wang,Sheng-xin Guo,Jian Wu
The high catalytic activity of photocatalysts is greatly influenced by the efficient separation of photogenerated charge carriers. In this study, six g-C 3 N 4 -based COFs are designed and synthesized, and CN-203 is identified as the most efficient photocatalyst through experimental screening. Quantitative measurements reveal that singlet oxygen production is ≈100 times that of ·O 2 − and 5000 times that of ·OH. When combined with PMS, CN-203 exhibits degradation rates for RhB and TC that are ≈30 ( k = 0.0293 s −1 ) and 10 ( k = 0.2940 min −1 ) times faster than those of CN550(RhB, k = 0.0531 min −1 ; TC, k = 0.0301 min −1 ), respectively. Structural simulations and calculations show that the modified CN-203 have better electron–hole separation in the excited state, and the energy gap between HOMO and LUMO is significantly reduced after modification. The study also revealed the structure–function relationship between the modification of the same site with different functional groups and its effect on photocatalysis. Overall, this study provides valuable insights into the relationship between surface structure and photocatalytic applications.
研究领域:
材料科学
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化学
·
环境科学
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
·
IF 9.5
Meng-Han Miao,Jin-Kai Qiu,Zhen-Liang Xu,Cheng Lian,Hong-Lai Liu,Jia-Hui Li,Yong-Jian Tang
Monomers are elementary units that constitute the polyamide layer, which determines the properties of nanofiltration membranes. The design of nanofiltration membranes with both high separation performance and outstanding chemical stability remains a challenge. In this study, two typical monomers, heterocyclic monomer molecule-piperazine (PIP) and carbon ring molecule-1,4-cyclohexane diamine (CHDA), were applied as aqueous monomers for interfacial polymerization to generate polyamide nanofiltration membranes. The physicochemical properties of the two nanofiltration membranes were comprehensively investigated. The results demonstrated that the nanofiltration membrane fabricated via CHDA exhibited more chemical stability than that fabricated via PIP. The mechanisms influencing the chemical stability difference were elucidated via multiscale simulation. The CHDA polyamide has higher levels of HOMO-LUMO energy and Gibbs-free energy, which make it more stable under harsh chemical environments. Overall, this work presents the effect of the diamine structure on the chemical stability of polyamide NF membranes, which can inspire highly chemically stable nanofiltration membrane fabrication.
研究领域:
材料科学
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化学工程
·
纳米技术
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产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2022
·
IF 2.719
Syed Adil Shah,Kuo-Juei Hu,Muhammad Naveed,Cao Lu,Shengyong Hu
Herein, gold-nanoclusters Au 6 (SR) 6 are synthesized in the argon atmosphere, using 2-phenylethanethiol and tetraoctylammonium bromide, as ligands and surfactants, respectively. Au 6 (SR) 6 possesses ca. 1.95 eV HOMO-LUMO gap, which is comparatively high and is also a dominant factor for quantum confinement effect. Moreover, the X-ray Photoelectron Spectroscopy (XPS) study shows the peak of Au 4f 7/2 appears at 86.89 eV, which describes the consistency regarding the size of clusters with XPS peak shift for Au 4f 7/2 value. In addition, the full width half maximum (FWHM) increases accordingly by decreasing the size of clusters.
研究领域:
纳米技术
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材料科学
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物理化学
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产品关联
DOI
高影响因子
Energy Storage Materials
·
2024
·
IF 18.9
Shuai Cui,Ting Li,Donggang Tao,Daohong Zhang,Yuliang Cao,Fei Xu
Rechargeable magnesium batteries are a potential selection for large-scale energy storage technologies, but development of cathode materials is the major difficulty at present. Organic polyimides are promising magnesium battery cathodes with the open and amorphous frameworks as well as enhanced charge delocalization. However, only two carbonyls are redox-active out of four for each imide unit, which largely limits the capacity. Herein, a new polyimide containing disulfide bond is fabricated and studied as cathode for rechargeable magnesium batteries. This polyimide shows a high capacity beyond the traditional two-electron principle. A mechanism study demonstrates that carbonyl enolization and disulfide bond break/formation occur in the redox process, leading to formation/break of sulfur-oxygen bond. This sulfur-oxygen bond enhances enolization and electron delocalization, resulting in an improved capacity. Further theoretical computation indicates a charge transfer within this sulfur-oxygen bond. The two-electron reduction state exhibits quite low HOMO and LUMO energy levels, which makes the disulfide bonded polyimide have a higher tendency to accept more electrons and a higher oxidation stability after reduction.
研究领域:
储能材料
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电化学
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高分子化学
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电池技术
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材料科学
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DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 91
·50277-50284
·
IF 3.708
Zonghai Shi,Yunshan Zhou,Lijuan Zhang,Cuncun Mu,Haizhou Ren,Daf ul Hassan,Di Yang,Hafiz Muhammad Asif
Three new supramolecular compounds [H2TPP]1.5[SW11VO40]·5CH3CN·4H2O 1, [H2TPP]2[SW10V2O40]·4CH3CN·3H2O 2, and [H2TPP][SW12O40]·4H2O 3 composed of [H2TPP]2+ cation and vanadium substituted Keggin-type polyoxometalate (POM) anion [SW12−nVnO40](2+n)− (n = 0–2) were prepared and characterized. The third-order nonlinear optical (NLO) and optical limiting (OL) properties of resulting hybrids were studied by using an Nd:YAG laser at 532 nm with a pulse duration of τ = 7 ns. The results demonstrate that all of these supramolecular compounds have significant nonlinear reverse saturated absorption, self-defocusing behavior, and good OL performance, especially for compound 1, which has a second hyperpolarizability γ value of 7.05 × 10−29 (esu) and exhibits a comparable OL performance with the most well-known OL materials such as In(Pc*)Cl indicating that they are potentially excellent NLO materials. Remarkably, it was also observed that the degree of vanadium substitution in POM anions corresponding to different onset of reduction potential influences the NLO and OL properties of the resulting compounds: third-order NLO and OL properties of compound 2 are inferior to those of compound 1, and are better than those of compound 3. Both their second hyperpolarizability γ values and the OL performance were observed to be inversely proportional to the HOMO–LUMO gaps of the resulting compounds. The excited charge transfer from porphyrin to POM anions in the supramolecular compounds when exposed to laser irradiation is thought to play key role in the enhancement of NLO and OL response.
研究领域:
材料科学
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光学
·
化学
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DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2025
·
IF 4.7
Hao Ai,Qiushuo Li,Qiong Xu,Xiangying Li,Degen Li,Qiong Wu
To elucidate the modulation mechanism of halogen substitution on the electronic structure and solid-state packing of half-Salen Schiff base complexes, a combination of single-crystal X-ray diffraction, spectroscopic characterization, and density functional theory (DFT) calculations was employed. The research reveals a subtle balance: constrained by the non-planar conformation of the ligand, chloro-substitution results in minimal perturbation of the frontier molecular orbitals (FMOs), with the HOMO-LUMO gap only slightly decreasing from 2.87 eV to 2.80 eV. In stark contrast, the intermolecular interactions are significantly enhanced. Hirshfeld surface analysis and binding energy (ΔE) calculations confirmed that the newly formed C–H···Cl and halogen-π non-covalent interactions increased the pathways for intermolecular interactions, strengthening the dimer binding energy from –23.67 kcal/mol to –25.90 kcal/mol. These findings deepen the understanding of the effects of halogen substitution and provide new experimental and theoretical evidence for the regulation of band gaps and intermolecular interactions in Schiff base complexes .
研究领域:
无机化学
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配位化学
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材料科学
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物理化学
·
晶体工程
·
理论化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）