COMPOSITES SCIENCE AND TECHNOLOGY
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2017
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IF 4.873
Wenjing Ji,Hua Deng,Qiang Fu
High dielectric constant filler is often used to improve the dielectric properties of polymer. Most studies are focused on the uniform filler dispersion and interface between filler and polymer. Herein, multi-layered films containing BaTiO 3 and multi-wall carbon nanotubes (MWCNTs) as fillers, with different filler distributions were designed and prepared, including alternating distribution of layers with/without filler; core-shell distribution with filler concentrated at core or shell; and uniform distribution. The overall filler content in these films was kept constant. These films have almost the same dielectric loss . Interestingly, it was noted that the largest dielectric constant is achieved for sample with filler concentrated at the shell (around 50% higher than the rest at low frequency). Interfacial polarization and filler localization are thought to play important role. However, classic Series model does not take these issues into account. To understand this, a modified Series model was proposed to calculate the dielectric constant of multi-layered films by considering these issues. Such equation is much more accurate at describing experimental results from current study as well as some published literature than classic Series model. Our work demonstrates the importance of hierarchical structure in polymer composites for dielectric property and heterogeneous distribution of filler could be much better than uniform distribution.
研究领域:
材料科学
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介电材料
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聚合物复合材料
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纳米复合材料
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电气工程
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POLYMER COMPOSITES
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2024
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IF 4.8
Jing Yan,Xiaojing Zhang,Ning Zhu,Yuebin Qin,Guang Yang
To address the need for efficient, flexible, and wearable power sources for portable electronics, a high performance triboelectric nanogenerator (TENG) was proposed by incorporating vertically-aligned barium titanate (BaTiO 3 )/antimony tin oxide (ATO) nanofibers in polydimethylsiloxane (PDMS) negative triboelectric layer, where BaTiO 3 served as piezoelectric material, and ATO served as conductive filler. Silver-coated conductive fabric was used as electrode to ensure integrability and wearability. By strategically coupling the triboelectric effect of PDMS, the piezoelectric effect of BaTiO 3 nanofibers, and the charge transfer effect of ATO nanofibers, the TENG exhibited the optimum output voltage and current of approximately 119 V and 28 μA, and power density of 11.74 μW/cm 2 , respectively. This device demonstrates its potential applications in energy supply by effectively illuminating 174 commercial green LEDs and charging capacitors for powering electronics. Additionally, the successful integration of the TENG into a smart fencing jacket highlights its utility in practical applications. Highlights TENGs with vertically-aligned BaTiO 3 /ATO composite nanofibers was constructed. The output performance of TENGs were enhanced by coupling triboelectric and piezoelectric effects. Conductive ATO nanofibers were incorporated to enhance charge transfer for performance enhancement. A smart fencing jacket with scoring system was developed using the wearable TENG.
研究领域:
材料科学
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纳米技术
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能量收集
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可穿戴电子
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JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2024
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IF 5.8
Danning He,Zhongyang Wang,Shuangqian Ma,Lan Yang,Liping Tong,Xiao Zhou,Tongxiang Fan
Broadband absorber materials with high solar absorptivity and infrared emissivity are conducive to high-efficient and cost-effective heating technology in the civil and industrial field. The BaTi 1- x Co x O 3 ceramics are prepared by sol-gel method, showing mixed tetragonal/hexagonal phases. Co doping slightly reduces the phase transition temperature of BaTiO 3 . Meanwhile, BaTi 1- x Co x O 3 ceramics present a composite Mott/charge transform band nature and the Co-3d impurity level and oxygen vacancies level lead to a narrowed bandgap. The enhancement of the absorption induced by free carriers, impurity level and lattice vibration promote the UV-Vis-NIR absorption and mid-infrared radiation of BaTi 1- x Co x O 3 ceramics. In conclusion, the optimized BaTi 0.95 Co 0.05 O 3 ceramic achieves a high solar absorptivity (0.88) in 0.25–2.5 µm and a high infrared emissivity (0.83) in 8–14 µm. The radiative performance presents good temperature stability, unaffected by phase structure and lattice thermal expansion, which provides prospective applications in solar energy conversion and infrared radiation heating.
研究领域:
材料科学
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太阳能转换
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红外辐射加热
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INORGANIC CHEMISTRY
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2026
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IF 4.6
Jingdong Yan,Xiangran Kong,Zichang Wang,Hongwei Leng,Tao Liu,Yunfei Shang,Nikolay Nikolaevich Yudin,Zuotao Lei,Chunhui Yang
Precise structural design is vital for advancing high-performance birefringent crystals used in mid-infrared polarizing devices. Mixed anion systems, particularly chalcohalides, present a promising avenue by synergistically combining the broad infrared transparency of chalcogenides with the band gap-widening capability conferred by halide ions. Guided by this approach, a novel chalcohalide birefringent crystal, Ba4CdGa2S6F4, was successfully designed and synthesized by the cation and anion cosubstitution strategy. This compound was derived from the parent phase Ba5Ga2S8 by partially replacing one Ba2+ cation with one Cd2+ cation and two S2– anions with four F– anions. Optical characterization via the UV–vis-NIR diffuse reflectance measurement reveals that Ba4CdGa2S6F4 exhibits a large optical band gap of 3.78 eV. And the broad infrared transparency of Ba4CdGa2S6F4 is confirmed for the material via both Raman and Fourier transform IR spectroscopy. First-principles calculations indicate that Ba4CdGa2S6F4 has moderate birefringence with a value of 0.057 at 1064 nm, representing a 26.6% increase over the parent compound Ba5Ga2S8. This work not only reports a promising infrared birefringent crystal with large band gap but also demonstrates that the cation and anion cosubstitution is an effective strategy for designing novel functional crystalline materials.
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Inorganic Chemistry Frontiers
·
2023
·Vol. 10
·期 7
·2030-2038
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IF 7
He-Di Yang,Sheng-Hua Zhou,Mao-Yin Ran,Xin-Tao Wu,Hua Lin,Qi-Long Zhu
Transition-metal-based chalcogenides have recently emerged as greatly promising infrared nonlinear optical (IR-NLO) candidates due to their unique structural chemistries and rich optical properties. However, Fe-based IR-NLO chalcogenides with phase-matching (PM) features have not yet been reported. In this work, a new non-centrosymmetric (NCS) melilite oxychalcogenide, Sr2FeGe2OS6, has been prepared by an isomorphous substitution method, and the relationships between the microscopic crystal structure and macroscopic NLO activity were systematically investigated. Sr2FeGe2OS6 adopts the tetragonal space group of P21m (no. 113) and features a unique two-dimensional structure with Cairo pentagonal tiling layers formed by the alternating connection of [Ge2OS6] dimers and [FeS4] tetrahedra via corner-sharing and with the charge-balanced Sr2+ cations between these layers. Excitingly, Sr2FeGe2OS6 is the first Fe-based example capable of achieving PM in the IR-NLO chalcogenide system and displays an outstanding IR-NLO comprehensive performance, including a wide energy gap (Eg = 2.24 eV), sufficient second-harmonic-generation (SHG) efficiency (deff = 5.89 pm V−1 at 2050 nm) and strong laser-induced damage threshold (LIDT = 14.42 MW cm−2). Deeper structural and theoretical analysis suggests that the ordered arrangement of NLO-active motifs, [Ge2OS6] dimers and [FeS4] tetrahedra, makes significant contributions to the strong deff and large birefringence (Δn). This work not only demonstrates a PM Fe-based NCS material for the first time but also puts forward a new design avenue for high-performance IR-NLO materials.
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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
·
2023
·Vol. 120
·期 16
·e2219923120
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IF 11.1
Qian-Yuan Wu,Zheng-Wei Yang,Zhi-Wei Wang,Wen-Long Wang
The high-valent cobalt–oxo species (Co(IV)=O) is being increasingly investigated for water purification because of its high redox potential, long half-life, and antiinterference properties. However, generation of Co(IV)=O is inefficient and unsustainable. Here, a cobalt-single-atom catalyst with N/O dual coordination was synthesized by O-doping engineering. The O-doped catalyst (Co-OCN) greatly activated peroxymonosulfate (PMS) and achieved a pollutant degradation kinetic constant of 73.12 min−1 g−2, which was 4.9 times higher than that of Co-CN (catalyst without O-doping) and higher than those of most reported single-atom catalytic PMS systems. Co-OCN/PMS realized Co(IV)=O dominant oxidation of pollutants by increasing the steady-state concentration of Co(IV)=O (1.03 × 10−10 M) by 5.9 times compared with Co-CN/PMS. A competitive kinetics calculation showed that the oxidation contribution of Co(IV)=O to micropollutant degradation was 97.5% during the Co-OCN/PMS process. Density functional theory calculations showed that O-doping influenced the charge density (increased the Bader charge transfer from 0.68 to 0.85 e), optimized the electron distribution of the Co center (increased the d-band center from −1.14 to −1.06 eV), enhanced the PMS adsorption energy from −2.46 to −3.03 eV, and lowered the energy barrier for generation of the key reaction intermediate (*O*H2O) during Co(IV)=O formation from 1.12 to 0.98 eV. The Co-OCN catalyst was fabricated on carbon felt for a flow-through device, which achieved continuous and efficient removal of micropollutants (degradation efficiency of >85% after 36 h operation). This study provides a new protocol for PMS activation and pollutant elimination through single-atom catalyst heteroatom-doping and high-valent metal–oxo formation during water purification.
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JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Wei Qiao,Jingwen Yang,Jiaxiao Qiao,Hejun Gao,Zexia Li,Peng Wang,Chaochao Cao,Jun Zhang,Yanming Xue,Chengchun Tang
Because they have a high application potential in the thermal management of insulation environments, high-quality hexagonal boron nitride (h-BN)-based multiphase ceramics have been highly desired. However, so far, their synthesis is still full of challenges. Here, a kind of boron nitride nanosheets (BNNSs)/glass (GS) composite ceramics was prepared by a pressureless sintering method at a lower temperature of 900 °C. Due to a tightly bonded interaction between BNNSs and GS, the formed BNNSs/GS ceramics exhibit excellent multifunction performance. They have an outstanding compressive strength in the range of 19 ∼ 64 MPa and Vickers hardness ranging from 50 to 179 HV. For the BNNSs/GS ceramics with BNNS’s filling fraction of 90 wt%, their maximum side-surface TC values are 12.01 ± 0.18 W m −1 K −1 at 25 °C and 13.64 ± 0.37 W m −1 K −1 at 300 °C, respectively. In the ultra-high frequency range of 26.5 ∼ 40 GHz, the dielectric constant values of the BNNSs/GS ceramics are primarily between 2 and 3, and the corresponding loss tangent values are < 0.3. In addition, based on the remarkable integrity of their structure, these BNNSs/GS ceramics exhibit outstanding thermal-shock stability and prominent thermal management capacity during lots of heating/cooling-testing cycles. Therefore, we believe this kind of BNNSs/GS ceramic system will have great application potential in the new-generation thermal management and/or insulation packaging fields.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Jun Wu,Ye Wang,Song Zhang,Yuxiang Liu,Feng Wang
Photocatalytic conversion of benzyl alcohol (BA) into value-added fine chemicals and hydrogen (H 2 ) in water medium provides a novel strategy for green synthesis. The construction of Z-scheme heterostructures not only realize enhanced charge-separation efficiency, but also remain strong drive force for photocatalytic reaction, which exhibit great potentials toward simultaneously generating benzaldehyde (BAD) and H 2 . Herein, we report a noble-metal-free Z-scheme photocatalytic system consisting poly(dibenzothiophene-S,S-dioxide) (PSO) and α-Fe 2 O 3 for selective oxidation of BA with synchronous H 2 production. Such nanocomposites can effectively transfer and reduce the recombination of photoexcited charge carriers, therefore maintaining the oxidizability of holes of α-Fe 2 O 3 and the reducibility of electrons of PSO. As expected, PSO-Fe 2 O 3 with a mass of ∼5 mg under optimal composition ratio exhibited an impressive photocatalytic activity with BAD and H 2 yields up to 23.1 and 29.5 μmol h −1 , respectively, which is among the top photocatalytic performance reported so far for selective photocatalytic oxidation of BA in the aqueous solution.
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Advanced Science
·
2022
·Vol. 10
·期 4
·2204755
·
IF 17.521
Shaoxin Cui,Hongping Wu,Zhanggui Hu,Jiyang Wang,Yicheng Wu,Hongwei Yu
Oxychalcogenides capable of exhibiting excellent balance among large second-harmonic generation (SHG) response, wide band gap ( E g ), and suitable birefringence (Δ n ) are ideal materials class for infrared nonlinear optical (IR NLO) crystals. However, rationally designing a new high-performance oxychalcogenide IR NLO crystal still faces a huge challenge because it requires the optimal orientations of the heteroanionic groups in oxychalcogenide. Herein, a series of antiperovskite-type oxychalcogenides, Ae 3 Q[GeOQ 3 ] (Ae = Ba, Sr; Q = S, Se), which were synthesized by employing the antiperovskite-type Ba 3 S[GeS 4 ] as the structure template. Their structures feature novel three-dimensinoal frameworks constructed by distorted [QAe 6 ] octahedra, which are further filled by [GeOQ 3 ] tetrahedra to form antiperovskite-type structures. Based on the unique antiperovskite-type structures, the favorable alignment of the polarizable [GeOQ 3 ] tetrahedra and distorted [QAe 6 ] octahedra have been achieved. These contribute the ideal combination of large SHG response (0.7–1.5 times that of AgGaS 2 ), wide E g (3.52–4.10 eV), and appropriate Δ n (0.017–0.035) in Ae 3 Q[GeOQ 3 ]. Theoretical calculations and crystal structure analyses revealed that the strong SHG and wide E g could be attributed to the polarizable [GeOQ 3 ] tetrahedra and distorted [QAe 6 ] octahedra. This research provides a new exemplification for the design of high-performance IR NLO materials.
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Advanced Healthcare Materials
·
2023
·Vol. 12
·期 15
·2202280
·
IF 10
Wenya Li,Rongtian Li,Qiang Ye,Yiming Zou,Xing Lu,Wenhua Zhang,Jinxiang Chen,Yinghua Zhao
Nanomedicine exhibits emerging potentials to deliver advanced therapeutic strategies in the fight against triple-negative breast cancer (TNBC). Nevertheless, it is still difficult to develop a precise codelivery system that integrates highly effective photosensitizers, low toxicity, and hydrophobicity. In this study, PCN-224 is selected as the carrier to enable effective cancer therapy through light-activated reactive oxygen species (ROS) formation, and the PCN-224@Mn 3 O 4 @HA is created in a simple one-step process by coating Mn 3 O 4 nanoshells on the PCN-224 template, which can then be used as an “ROS activator” to exert catalase- and glutathione peroxidase-like activities to alleviate tumor hypoxia while reducing tumor reducibility, leading to improved photodynamic therapeutic (PDT) effect of PCN-224. Meanwhile, Mn 2+ produced cytotoxic hydroxyl radicals (∙OH) via the Fenton-like reaction, thus producing a promising spontaneous chemodynamic therapeutic (CDT) effect. Importantly, by remodeling the tumor microenvironment (TME), Mn 3 O 4 nanoshells downregulated hypoxia-inducible factor 1 α expression, inhibiting tumor growth and preventing tumor revival. Thus, the developed nanoshells, via light-controlled ROS formation and multimodality imaging abilities, can effectively inhibit tumor proliferation through synergistic PDT/CDT, and prevent tumor resurgence by remodeling TME.
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Journal of Physical Chemistry C
·
2022
·
IF 4.177
Donghui Wang,Yu-e Shi,Zhen Zhang,Song Shen,Zhenguang Wang
Construction of red afterglow materials through a straightforward synthesis method is promising but still a challenging task. In this work, a boric acid (BA)-assisted energy transfer strategy was proposed to modulate the emission of levofloxacin (Lev) and rhodamine B (RhB) into red afterglow, with an emission lifetime of 0.54 s and a photoluminescence quantum yield of 54.1%. Detailed investigations suggested that the heat treatment process resulted in the formation of a BA matrix, accompanied by the loading of Lev and RhB. The BA matrix activated the thermally activated delayed fluorescence of Lev, and its emission intensity was promoted through reducing the molecular motion and quenching effects from environments. The red afterglow was attributed to the energy transfer from activated Lev to RhB through both singlet state to singlet state and triplet state to singlet state processes. The applications of red afterglow materials for information encryption were also demonstrated. The present results opened a door for designing red afterglow materials, which also presented a solid theory to explain the energy transfer profiles.
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ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Xiangnan He,Jianxiang Cheng,Zhenqing Li,Haitao Ye,Xinfeng Wei,Honggeng Li,Rong Wang,Yuan-Fang Zhang,Hui Ying Yang,Chuanfei Guo,Qi Ge
Ionic conductive elastomers (ICEs) are emerging stretchable and ionic conductive materials that are solvent-free and thus demonstrate excellent thermal stability. Three-dimensional (3D) printing that creates complex 3D structures in free forms is considered as an ideal approach to manufacture sophisticated ICE-based devices. However, the current technologies constrain 3D printed ICE structures in a single material, which greatly limits functionality and performance of ICE-based devices and machines. Here, we report a digital light processing (DLP)-based multimaterial 3D printing capability to seemly integrate ultraviolet-curable ICE (UV-ICE) with nonconductive materials to create ionic flexible electronic devices in 3D forms with enhanced performance. This unique capability allows us to readily manufacture various 3D flexible electronic devices. To demonstrate this, we printed UV-ICE circuits into polymer substrates with different mechanical properties to create resistive strain and force sensors; we printed flexible capacitive sensors with high sensitivity (2 kPa–1) and a wide range of measured pressures (from 5 Pa to 550 kPa) by creating a complex microstructure in the dielectric layer; we even realized ionic conductor-activated four-dimensional (4D) printing by printing a UV-ICE circuit into a shape memory polymer substrate. The proposed approach paves a new efficient way to realize multifunctional flexible devices and machines by bonding ICEs with other polymers in 3D forms.
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危险品化学品经营许可证（带存储）