Crystals
·
2020
·Vol. 10
·期 8
·698
·
IF 2.404
Mengdi Fan,Guangda Wu,Fapeng Yu,Lili Li,Yanlu Li,Xiufeng Cheng,Xian Zhao
The bismuth layer-structured ferroelectrics (BLSFs) materials have potential for high-temperature piezoelectric applications. Among these piezoelectric materials, the CaBi4Ti4O15(CBT) piezoelectric ceramic with a high decomposition temperature of about 1250 °C attracts a lot of attention. Achieving a CBT single crystal is a significant way to improve its piezoelectric properties. For this purpose, the flux system for growing CBT crystal was explored in this study. The optimum flux composition ratio was found to be PbO:B2O3:CBT = 3:3:1 in mol%, where the PbO–B2O3mixtures were used as a flux system. Millimeter size flake-shaped CBT crystals were obtained using the spontaneous growth process for the first time. The relationship between the crystal structure and flake growth habit was analyzed. In addition, the bandgap was evaluated by the combination of transmittance spectrum and first-principle calculations. Besides, the piezoelectric property was predicted from the perspective of polyhedral distortion, which indicated the potential of CBT crystal for piezoelectric applications.Keywords:CaBi4Ti4O15;single crystal growth;flux method;dipole moments
研究领域:
材料科学
·
晶体学
✓ 已验证
产品关联
DOI
高影响因子
National Science Review
·
2019
·Vol. 7
·期 3
·652-659
·
IF 13.222
Chen Xianjie,Xu Yuan,Ma Xinguo,Zhu Yongfa
Herein, a wide-spectrum (∼678 nm) responsive Bi8(CrO4)O11 photocatalyst with a theoretical solar spectrum efficiency of 42.0% was successfully constructed. Bi8(CrO4)O11 showed highly efficient and stable photocatalytic water oxidation activity with a notable apparent quantum efficiency of 2.87% (420 nm), superior to many reported wide-spectrum driven photocatalysts. Most remarkably, its strong oxidation ability also enables the simultaneous degradation and complete mineralization for phenol, and its excellent performance is about 23.0 and 2.9 times higher than CdS and P25-TiO2, respectively. Its high activity is ascribed to the giant internal electric field induced by its large crystal dipole, which accelerates the rapid separation of photogenerated electron–hole pairs. Briefly, the discovery of wide-spectrum bismuth chromate and the mechanism of exponentially enhanced photocatalytic performance by increasing the crystal dipole throw light on improving solar energy conversion.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-11
·
IF 14.7
Wang Xin,Liu Boyan,Ma Siqing,Zhang Yingjuan,Wang Lianzhou,Zhu Gangqiang,Huang Wei,Wang Songcan
Amorphous semiconductors without perfect crystalline lattice structures are usually considered to be unfavorable for photocatalysis due to the presence of enriched trap states and defects. Here we demonstrate that breaking long-range atomic order in an amorphous ZnCdS photocatalyst can induce dipole moments and generate strong electric fields within the particles which facilitates charge separation and transfer. Loading 1 wt.% of low-cost Co-MoS x cocatalysts to the ZnCdS material increases the H 2 evolution rate to 70.13 mmol g −1 h −1 , which is over 5 times higher than its crystalline counterpart and is stable over the long-term up to 160 h. A flexible 20 cm × 20 cm Co-MoS x /ZnCdS film is prepared by a facile blade-coating technique and can generate numerous observable H 2 bubbles under natural sunlight, exhibiting potential for scale-up solar H 2 production.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Shiyuan Liu,Xiaoli Wu,Zhirong Yang,Jie Zhang,Yifan Li,Jingtao Wang
Separation of the xylene isomers has always been of great challenge and interest to the industry. Here, separation factors of 51 and 9 for p -/ o -xylene and p -/ m -xylene with a p -xylene permeance of 1.2 × 10 −7 and 2.2 × 10 −7 mol m −2 s −1 Pa −1 , respectively, are achieved on the simple tandem fluorinated MXene lamellar membranes with 11%F and 1%F content through insight into the inversion behavior of the adsorption configuration enabled by the difference in dipole moments of xylenes under the combined interaction of xylene–CH 3 … F attraction and xylene–π–bond … F repulsion. The favorable configuration of p -xylene maintains the flat adsorption, while that of m - and o -xylene undergoes a transition from upright to tilted and flat adsorption. DFT calculations confirm the weak flat adsorption of p -xylene on MXene-11%F repelled by the π–bond … F repulsion and the strong upright adsorption of m - and o -xylene via the regulation of the repulsion, which contributes to a high throughput of p -xylene. As the F content decreases to 1 %, the low π–bond … F repulsion results in strong flat configuration of p -xylene and weak flat configuration of m - and o -xylene. This work provides ideas for separating isomers by controlling the adsorption configuration through understanding their interaction forces in the membrane channel.
研究领域:
材料科学
·
化学工程
·
理论化学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2024
·
IF 4.1
Rui Lin,Hui Zhou,Xuee Xu,Xinhua Ouyang
Applying solid additive into the active layer has been demonstrated to be one of the most efficient approaches in improving the photovoltaic performance of organic solar cells (OSCs). Through the combination of 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile and benzodithiophene units, this work presents a novel donor-acceptor type solid additive IC-BDTBr . The IC-BDTBr additive possesses a large dipole moment with an efficient intramolecular charge transfer, attributed to the push-pull effect and the S⋯O noncovalently conformational lock. It is able to form strong electrostatic interaction with the active layer materials, which helps to tune the miscibility. Thus, the charge transport of OSCs is significantly promoted by the incorporation of IC-BDTBr . The IC-BDTBr additive exhibits suitable energy levels and optical absorption, which enhances the photovoltaic performance of the devices. As a result, incorporating the IC-BDTBr additive into the active layer improves both the photocurrent and fill factor of the OSCs. Thus, the average power conversion efficiency (PCE) is increased from 15.70 % of the PM6:Y6 control device to 16.51 % (PCE max = 16.60 %) of the device with 2 wt% IC-BDTBr . This research demonstrates a feasible design strategy for the solid additive, by applying a donor-acceptor molecular structure with large dipole moment.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 18
·25063-25068
·
IF 5.6
Limei Hou,Weihao Zhai,Yingfei Xin,Yating Zhuang,Chongyang Fu,Shanmei Du,Jin Wang,Xiaoxiong Wang
Flexoelectric effect refers to the phenomenon of electric polarization under the action of material deformation gradient . When the material is strained, the local strain gradient will cause the electric dipole moment to rearrange , thereby generating an electric field in the material. Different from the piezoelectric effect , the flexoelectric effect is not limited by the symmetry of materials. Furthermore, the flexoelectric effect exhibits a significant size effect , allowing for huge flexoelectric signals to be obtained in nanoscale systems. Therefore, the flexoelectric effect has a wider application prospect and development space. There are differences in the number dimension between the flexoelectric coefficient and the piezoelectric coefficient , but both flexoelectric and piezoelectric effects result in the induction of electric dipole moments. In analogy to the piezoelectric effect, the polarization intensity may influence the flexoelectric coefficient. In this study, we selected the typical piezoelectric material barium titanate (BaTiO 3 ) and employed the forward/reverse and continuous polarization method to regulate the dipole moment arrangement. We measured the piezoelectric-like effect and flexoelectric-like effect under different polarization voltages with using a quasi-static d 33 measuring instrument and a two-step dot-loop method. The results confirmed that the polarization process intrinsically enhances the flexoelectric coefficient. At a polarization voltage of 600 V, the flexoelectric-like coefficient reached 180 pC/N, which is more than twenty times stronger than that of the non-polarized sample (7 pC/N). This study provides a simple and feasible idea for the enhancement of macroscopic flexoelectric coefficients.
研究领域:
材料科学
·
凝聚态物理
·
功能材料
·
纳米力学
·
介电物理
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-12
·
IF 14.7
Cheng Chang,Yu Jiaguo,Xu Difa,Wang Lei,Liang Guijie,Zhang Liuyang,Jaroniec Mietek
Donor-acceptor semiconducting polymers present countless opportunities for application in photocatalysis. Previous studies have showcased their advantages through direct bottom-up methods. Unfortunately, these approaches often involve harsh reaction conditions, overlooking the impact of uncontrolled polymerization degrees on photocatalysis. Besides, the mechanism behind the separation of electron-hole pairs (excitons) in donor-acceptor polymers remains elusive. This study presents a post-synthetic method involving the light-induced transformation of the building blocks of hyper-cross-linked polymers from donor-carbon-donor to donor-carbon-acceptor states, resulting in a polymer with a substantial intramolecular dipole moment. Thus, excitons are efficiently separated in the transformed polymer. The utility of this strategy is exemplified by the enhanced photocatalytic hydrogen peroxide synthesis. Encouragingly, our observations reveal the formation of intramolecular charge transfer states using time-resolved techniques, confirming transient exciton behavior involving separation and relaxation. This light-induced method not only guides the development of highly efficient donor-acceptor polymer photocatalysts but also applies to various fields, including organic solar cells, light-emitting diodes, and sensors.
研究领域:
材料科学
·
光化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 4
·1380-1390
·
IF 6.641
Hui Zhang,Yanxin Tian,Shuhui Bo,Linghan Xiao,Yuhui Ao,Ji Zhang,Ming Li
In order to improve the first-order hyperpolarizability (β) of the chromophore and transform it into a high macroscopic electro-optic activity, a series of novel second-order nonlinear optical chromophores with different push–pull electron groups introduced on the thiophene π-conjugate bridge for tuning the shape and dipole moment (μ) of chromophores were designed and synthesized. These chromophores are based on the same thiophene π-conjugated bridge, where the donor (N,N-diethylaniline) and acceptor (2-(3-cyano-4,5,5-trimethylfuran-2(5H)-ylidene)malononitrile or malononitrile) are linked to positions 2 and 3 of thiophene, respectively, affording a boomerang-like shape instead of a rod-like shape. Besides, an electron-poor group, Br (bromine atom), or an electron-rich group, DEA (N,N-diethylaniline), as an auxiliary acceptor or donor are linked to position 5 of thiophene. In addition, all chromophores showed good thermal stability as per the results from the DSC and TGA analysis. Through UV-vis analysis and DFT calculation, it has been concluded that chromophores with additional electron-rich groups as auxiliary donors display better intermolecular charge-transfer (ICT) absorption and lower HOMO–LUMO energy gaps (ΔE). Furthermore, the boomerang-like chromophore with the same push–pull structure shows a smaller dipole moment (μ) and β value than the traditional FTC. The poling results of guest–host EO polymers FTC/APC, FTC-H/APC, FTC-Br/APC and FTC-DEA/APC with the same number density afford r33 values of 17 pm V−1, 11 pm V−1, 10 pm V−1 and 25 pm V−1, respectively. Although the β value of FTC-DEA is smaller than that of FTC, the r33 value of FTC-DEA (25 pm V−1) is 47% greater than that of FTC (17 pm V−1) under the same number density. Hence, the above-mentioned results indicated that regulating the conjugate position of chromophores can efficiently decrease the dipole moment of the chromophores, weakening the dipole–dipole interactions and thereby enhancing the macroscopic electro-optical activity of poled polymers. These results indicate the potential application of these novel chromophores in electro-optical devices.
研究领域:
材料科学
·
有机化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Ze-Hui Dai,Jia-Rui Han,Yang Gao,Jun Xu,Jinliang He,Bao-Hua Guo
Polymer nanocomposites with high dielectric permittivity ( ε ) are urgently demanded for power energy storage. In this research, in order to prepare nanocomposites with strong interfacial interactions and higher ε , a novel surface modification molecule, 3,4,5-trihydroxybenzoic acid (or Gallic acid, GA), was developed. There are two main advantages for selecting GA as the coating molecule. Firstly, the polar groups, such as hydroxyl and carboxyl groups in GA, could form hydrogen-bonding interaction with poly(vinylidene fluoride- co -chlorotrifluoroethylene) (PVDF-CTFE). Therefore, though thickness of coating layer is only 1.6 nm, nanocomposites with better dispersion were prepared by strengthening hydrogen-bonding interaction at polymer-nanoparticle interface. Secondly, functional groups with high bond dipole moment, such as carboxyl groups and phenolic groups, are beneficial to obtain high ε in PVDF-CTFE + BT@GA. ε is 25.6 at 1 kHz with 12.9% BT@GA. This is about 2.5 times higher than that of PVDF-CTFE matrix (10.4 at 1 kHz). The hypothesis in this research might offer a feasible approach to prepare capacitors with higher ε and higher energy density by regulating bond dipole moment of functional groups in the coating molecules.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2015
·
IF 2.486
Kun Hu,Pei Chen,Qiang Weng,Dingqian Shi,Ran Chen,Xinbing Chen,Zhongwei An
By modifying the molecular dipole moments with lateral monofluorine substituent, improved mesophase stabilities were obtained for novel benzoxazole derivatives, 2-(4ʹ-alkoxy-3-fluorobiphenyl-4-yl)-benzoxazole liquid crystals (coded as nPPF(3)Bx). The series of nPPF(3)Bx with lateral monofluorine substituent ortho to benzoxazole group have larger calculated dipole moments by about 2 D than the corresponding fluorine-substituted analogs (compounds I) with lateral monofluorine ortho to alkoxy group; it is interesting to note that they show lower melting and clearing points but better mesophase stability with wider mesophase ranges for the molecules with both polar (NO2, Cl) and nonpolar (CH3, H) terminal groups. Meanwhile, compounds nPPF(3)Bx show greater red-shifted photoluminescence emissions than compounds I, which suggest that π–π interaction between molecules is reinforced by the enhanced dipole–dipole interaction caused by increased dipole moments. These results suggest that modification of the molecular dipole moment is an effective method to improve the mesophase stability of the classical mesogenic compounds.
研究领域:
材料化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Rong Yan,Meiyang Song,Peng Chen,Henghui Song,Chengbing Fu,Haiyang Peng,Shuang-Feng Yin
Designing a robust built-in electric field (BF) is a charming strategy for enhancing the separation and transportation of charges via introducing large π-conjugated molecules. However, it has flexible or semiflexible geometries, which significantly disorder the crystalline and deteriorated the built-in electric field. Here, a straightforward tactic for creating a cyano-functionalized smaller D (benzene) - A (triazine) units in PDI- triazine based polymer (PDIMB) to enhance intrinsic molecule dipole has been proposed. The density functional theory (DFT) calculation revealed that the modification of smaller D-A groups destroyed the π-localization of charges, which enhanced the molecular dipole and the BF for promoting the exciton dissociation and charge transfer. Moreover, it not only exposed number of active sites, but also enhanced the interfacial molecular interacting. Therefore, PDIMB-2 exhibits high activity (24.5 mmol g -1 h -1 ) and selectivity (>99%) for the photooxidation of benzylamine to N -benzylidenebenzylamine under mild conditions. Our work offers a potential and simple synthetic option for enhancing the built-in electric field of polymer.
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Jikai Qiu,Zhipeng Liu,Tao Yuan,Shuai Bai,Xiangxin Zhang,Junting Chen,Yining Zhang
The reversibility and stability of aqueous zinc-ion batteries (AZIBs) are largely limited by free-water-induced side reactions (e.g., hydrogen evolution and zinc corrosion) and negative zinc dendrite growth. To address these issues, we introduced triethyl 2-phosphonopropionate (Tp), a novel high-dipole-moment electrolyte additive. Tp effectively replaces free water in the electrolyte through strong ion–dipole interactions, altering the solvation structure and suppressing hydrogen evolution and zinc corrosion at the zinc anode. Additionally, the high binding energy between Tp and zinc foil ensures that Tp adheres firmly to the zinc anode surface, while the hydrophobic alkyl chains repel free water, modifying the interfacial structure of the zinc anode, promoting reversible zinc deposition, and effectively suppressing zinc dendrite growth. With these excellent properties, the optimal concentration of Tp enables a cycle time of over 770 h for 1 mA cm −2 and 1 mAh cm −2 symmetric cells, which is 7.7 times longer than that of pure electrolyte. Furthermore, the cycle number of Zn//Na 2 V 6 O 16 full cells increased from 600 to 4000 cycles compared to pure electrolyte, with capacity retention improved from 70 % to 92 %. These results highlight the significance of high-dipole moment electrolyte additives, provide new insights into electrolyte modification strategies, and are expected to accelerate the commercialization of AZIBs for practical applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）