APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Hui Niu,Huan Lin,Huiting Zhang,Longfeng Hu,Gangqiang Yu,Shuhong Wu,Jinlin Long,Quan-Fu An
Photocatalytic hydrogen evolution presents a sustainable method for clean energy generation, yet its efficiency remains limited by insufficient charge separation and transfer. Herein, we report a novel strategy to enhance photocatalytic efficiency by integrating both bulk and surface electric fields within self-assembled supramolecular photocatalyst. We synthesized perylene 3,4-dicarboxylic acid (PDA) with a large dipole moment and polar carboxyl groups, which self-assembles into ultrathin 2D nanosheets in water. The accumulation of dipole moments induces a bulk electric field, enabling ultrafast exciton dissociation into free charges. Concurrently, the exposed carboxyl groups generate a surface electric field, facilitating efficient charge extraction and transfer on the surface for proton reduction. The synergistic interplay between bulk and surface electric fields results in an impressive photocatalytic hydrogen production rate of 3.2 mmol g⁻¹ h⁻¹ , significantly surpassing that of the other perylene-based nanosheets relying solely on either bulk or surface electric fields. This study offers valuable insights into the distinct roles of bulk and surface electric fields in photocatalytic processes, and introduces a new design paradigm for photocatalysts to enhance solar-to-hydrogen conversion efficiency.
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
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2024
·
IF 3.7
Donghai Yang,Mofan Li,Qing Yun,Huayao Sun,Qing Li,Xuedong Gao,Chaohui Chen,Limin He
Electrocoalescence technology can efficiently dehydrate waxy crude oil but the mechanisms are still unclear. Herein, the continuous microscopic behaviors of droplet falling, deformation, and coalescence were experimentally investigated to clarify the dynamic response mechanism of droplet in waxy oil under an electric field. The results showed the droplet falling under both gravity and electrostatic attraction to deform by the electric field force. Moreover, the expansion and clamping of the liquid bridge resulted from the competition between electric field force and capillary force. However, the precipitated wax crystals reduced the kinetic energy of the droplet and affected its external circulation, thus delaying the falling time. In addition, the wax crystals with interfacial activity adsorbed on the oil-water interface and cross-linked to form a spatial network structure, thereby weakening droplet deformation, hindering liquid film drainage, and inhibiting liquid bridge expansion. Importantly, the droplet adsorbed wax crystals exhibited interfacial elasticity, which makes them more inclined to partial coalescence. The low-frequency pulsed direct current (PUDC) electric field with high strength intermittent effect displayed the most obvious inhibition effect on the wax crystals. Overall, these findings look promising for future design and optimization of high-efficiency electric dehydrators and related fields.
研究领域:
石油工程
·
界面科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2020
·
IF 3.557
Xin Huang,Limin He,Xiaoming Luo,Ke Xu,Yuling Lü,Donghai Yang
Electrocoalescence technology is an important method for the demulsification of crude oil emulsion, but its development is restricted by the short circuit caused by droplet chain formation. To reveal the formation mechanism of droplet chains, the electrocoalescence behaviors of two droplets and droplet clusters under pulsed direct current (DC) electric fields are experimentally studied. The two droplets usually successively undergo complete coalescence, partial coalescence, and noncoalescence as the electric field strength increases. The critical electric field strengths for complete coalescence under pulsed DC electric fields with different frequencies are obtained. The effects of the electric field waveform and frequency on the noncoalescence characteristics of two droplets and the stability of droplet chains are explored. The droplet chains under a high-frequency electric field are more stable and longer than those under a low-frequency electric field due to the reduction of the movement distance and the generation of daughter droplets from tip streaming. The reversal of the composition of electric forces due to charge transfer is the fundamental mechanism of noncoalescence of two droplets and chain formation in the emulsion under a pulsed DC electric field.
研究领域:
物理学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Meng Li,Jingxue Sun,Gang Chen,Shunyu Yao,Bowen Cong
When internally polarized by mechanical energy, piezoelectric materials can establish polarization electric field and provide driving force for separating photogenerated carriers. Herein, S vacancies are introduced as an intermediate to make metal ions form coordination bond with F - on PVDF (polyvinylidene fluoride) surface, and the built-in electric field is intimately related to polarized electric field. We successfully synthesized ZnS/Bi 2 S 3 -PVDF film photocatalyst containing S vacancies (ZnS-V S /Bi 2 S 3 -PVDF). Polarized electric field on PVDF caused by ultrasonic cavitation and built-in electric field formed between ZnS-V S /Bi 2 S 3 heterojunction structure are beneficial to interfacial charge transferring. Theoretical calculation simulation demonstrate that the synergistic effect of the double electric fields is propitious to inhibit the recombination of carriers. The hydrogen evolution rate of ZnS-V S /Bi 2 S 3 -PVDF reaches 10.07 mmol h −1 g −1 . Moreover, it has excellent reversibility and facile recovery capacity. This work provides new platform for photocatalytic reduction of hydrogen evolution and is expected to contribute to clean energy production.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2025
·
IF 2.6
Jiangwen Bai,Jiamin Li,Jinmeng Xiang,Chongfeng Guo
The built-in electric field (IEF) between two components of heterojunction has been proven to be capable of efficiently separating photogenerated carriers in photocatalysis. However, the rapid charge accumulation near the interface of heterojunction tends to neutralize this electric field, resulting in the deterioration of the heterojunction performance. Herein, the ferroelectric-based BiFeO3/BiOI-n heterojunctions (BFO/BiOI-n) were prepared utilizing epitaxy growth. The BFO not only endows the heterojunctions with stronger ferroelectric polarization, which was confirmed by the hysteresis loop, but also induces a significant redistribution of carriers, which maintains a stronger IEF in BFO/BiOI-n. Furthermore, the ferroelectric polarization of BFO was further regulated via corona poling and the enlarged ferroelectric polarization was also favorable to improve the photocatalytic performance. The optimal PBFO/BiOI-4 sample delivers a complete degradation of RhB within 30 minutes and a hydrogen evolution rate of 150 µmol·g−1·h−1. The significantly improved photocatalytic performance is attributed to the efficient photogenerated carriers separation synergistically promoted by the IEF in the heterojunction and the polarized electric field (PEF) in BFO. This work provides a feasible scheme for designing ferroelectric-based heterojunction photocatalyst.
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2024
·
IF 15.7
Chao Li,Shuo Wang,Yuan Liu,Xihe Huang,Yan Zhuang,Shuhong Wu,Ying Wang,Na Wen,Kaifeng Wu,Zhengxin Ding,Jinlin Long
ABSTRACT Covalent organic frameworks (COFs) are promising materials for converting solar energy into green hydrogen. However, limited charge separation and transport in COFs impede their application in the photocatalytic hydrogen evolution reaction (HER). In this study, the intrinsically tunable internal bond electric field (IBEF) at the imine bonds of COFs was manipulated to cooperate with the internal molecular electric field (IMEF) induced by the donor-acceptor (D-A) structure for an efficient HER. The aligned orientation of IBEF and IMEF resulted in a remarkable H 2 evolution rate of 57.3 mmol·g –1 ·h –1 on TNCA, which was approximately 520 times higher than that of TCNA (0.11 mmol·g –1 ·h –1 ) with the opposing electric field orientation. The superposition of the dual electric fields enables the IBEF to function as an accelerating field for electron transfer, kinetically facilitating the migration of photogenerated electrons from D to A. Furthermore, theoretical calculations indicate that the inhomogeneous charge distribution at the C and N atoms in TNCA not only provides a strong driving force for carrier transfer but also effectively hinders the return of free electrons to the valence band, improving the utilization of photoelectrons. This strategy of fabricating dual electric fields in COFs offers a novel approach to designing photocatalysts for clean energy synthesis.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
·
2021
·
IF 3.186
Xin Huang,Limin He,Xiaoming Luo,Ke Xu,Yuling Lü,Donghai Yang
s The coalescence behaviors of two neutral droplets suspended in silicone oil under the alternating current (AC) and pulsed direct current (DC) electric fields are investigated by experiments and numerical simulations. The distribution evolutions of electric force and velocity field during the droplet coalescence under the AC and pulsed DC electric fields are analyzed. The relationship between electric field excitation and droplet interface response is illustrated. The equivalent response mechanism of droplets under the high-frequency AC and pulsed DC electric fields and under the DC electric fields is revealed. The relationship of droplet dynamic behaviors under the DC electric field and under the AC and pulsed DC electric fields are established. The critical electric field frequencies above which the shortest distance curves no longer change under the AC and pulsed DC electric fields are obtained. These new findings are significant for the optimization of electrostatic coalescence.
研究领域:
物理学
·
流体力学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2019
·Vol. 66
·期 4
·e16869
·
IF 3.463
Xin Huang,Limin He,Xiaoming Luo,Haoran Yin
Droplet dynamic response in low-viscosity fluid under a pulsed direct-current (DC) electric field and a sinusoidal electric field is investigated by experiments and numerical simulations. The coupled level set and volume of fluid method is employed to capture moving interface and the numerical method is validated by experimental results. This article focuses on the effects of waveform, frequency and initial phase on the dynamic response. The deformation period is identical with the electric period for the pulsed DC electric field but the deformation period is half of the electric period for the sinusoidal electric field. As the frequency increases, the maximum deformation degree D max first climbs steadily to a peak value, then decreases steeply and finally approaches an equilibrium value. The maximum D max appears at f = 50 Hz for the pulsed DC electric field and appears at f = 100 Hz for the sinusoidal electric field according to numerical results. These results are helpful for the optimization of electro-coalescence.
研究领域:
物理学
·
工程学
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Siqi Qi,Min Lin,Pengfei Qi,Junjie Shi,Ge Song,Wenxin Fan,Kunyan Sui,Congjie Gao
With the aggravation of pollutants damage to the environment, it is crucial yet rather challenging to design powerful matrixes for nanomaterials with high ions permeability and migration, as well as multiple exposed active sites. However, most of the current nanomaterial matrixes just act as carrier supporters with introduced invalid mass. Here, a gradient natural polycation electrolyte (chitosan) hydrogel was engineered as nanomaterials matrix to boost anionic heavy metals removal such as antimonate (Sb(V)) and arsenate (As(V)) for the first time, based on the generated interfacial and build-in electric potentials due to the diffusion of counterions. The resulting dual electric potentials allow for rapid diffusion and removal efficiency of heavy metal ions. Exemplified by Sb(V) removal, the chitosan gradient hydrogel matrixes with embedded UiO-66 MOFs exhibited a 3-fold higher removal velocity than the homogeneous hydrogel matrix, and their removal efficiencies were also promoted by gathering on the high charge density side of hydrogels. In contrast to the other reported matrix materials without driving force, the gradient polyelectrolyte hydrogel can greatly boost the removal efficiency and shorten the treatment times. This study offers inspirations on eliminating heavy metal contaminations based on self-driving forces stemming from the heterogeneous structure of materials.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
AIP Advances
·
2018
·Vol. 8
·期 8
·
IF 1.653
Zhu Ziming,Xu Guojie,Chen Rouxi,Wang Zhifeng,Huang Jiaxu,Chen Xindu,Zeng Jun,Liang Feng,Fang Feiyu,Wang Han,Wu Peixuan,He Yunbo,Zhao Yixiang,Li Yang
The electrospinning electric field is the main factor responsible for the jet stretching force. Previous studies showed that nonhomogeneous electric field would affect the jets formed during the multi-needles electrospinning. Therefore, a multitude of methods were explored to optimize the electric field in multi-needles electrospinning, such as adjusting the supplied voltage on each needle, varying the space of the needles and spatial distribution of the needles. In this paper, three categories of needles distribution were explored for a homogeneous electric field and the design of a higher needles density of electrospinning head. The theoretical and experimental results showed that the homogeneous electric field formed with the trapezoidal head at 15mm distance while the others’ head required over 30mm. Hence, the trapezoidal arrangement is a better multi-needles distribution for electrospinning head, and has much more significance for high yield of electrospinning nanofibers.
研究领域:
材料科学
·
静电纺丝技术
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Lu Jing,Weili Li,Chang Gao,Menglu Li,Weidong Fei
Polymer-based dielectric capacitors are well recognized for high energy density and efficiency. However, the energy density is restricted by the deterioration of breakdown strength with excessive addition of inorganic fillers. Herein, an innovative design of the lamellar-structured BiFeO 3 @TiO 2 (BFO@TO) fillers is proposed and a small amount of BFO@TO is added into P(VDF-HFP)/PMMA blended polymer to fabricate BFO@TO-P(VDF-HFP)/PMMA composites, which delivers an outstanding energy density of 19.3 J cm −3 at 549.2 kV mm −1 . The filler possesses a BFO/TO/BFO triple-layered structure. Due to the different Fermi level, electrons are injected from TO into BFO to form electron accumulation layer and construct the heterojunction electric fields between TO and BFO layers. Heterojunction electric fields at two interfaces produced by the triple-layered structure are opposite. The opposite double heterojunction can withstand larger external electric field and improve the breakdown strength. Besides, BFO, as a narrow bandgap semiconductor, is easier for electrons and holes to separate, which further widens the width of the built-in electric field and reduces the dielectric breakdown. Electric field distribution simulations intuitively confirm the enhancement of the breakdown strength. The results provide an effective strategy to address the critical issue of improving the breakdown strength for high energy storage capability.
研究领域:
材料科学
·
电气工程
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Smart Materials and Structures
·
2020
·Vol. 29
·期 2
·025009
·
IF 3.613
Chenguang Niu,Xufeng Dong,Yuan Lan,Linkai Niu,Xiaoyan Xiong,Bin Zhao,Min Qi
The creep and recovery behaviors are of great importance for the electrorheological elastomers (EREs), while it is lack of relevant research in previous reports. In this work, the creep and recovery properties of silane coupling agent modified-TiO2 particles based EREs were systematically investigated, and the influence of particle content, electric field strength and temperature on creep and recovery behaviors were analyzed. The results indicate the creep and recovery behaviors of the EREs are affected by particle volume fraction and temperature obviously. The creep resistance of EREs are enhanced with the ascending electric field strength, and the blocking effect of particles on polymer chain segments is further clarified by fitting the creep data with Findley and Burgers model. The creep compliance curves of the EREs under various temperatures and electric field intensities were compared, and the curves were shifted along time axis to get a master compliance curve at a reference electric field strength according to the proposed time-electric field superposition principle (TESP). It is shown that TESP could provide an accelerated measuring technique for evaluating the long-term viscoelastic properties of EREs.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）