Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 42
·20760-20768
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IF 9.931
Xiaoqin Sun,Fangfang Wu,Gang Liu,Xiaoxiang Xu
The perovskite oxynitride SrTaO2N is a promising compound for solar energy conversion because it has strong visible light absorption at wavelengths as long as 650 nm. However, its photocatalytic activity is generally very poor, primarily because of the high defect concentration induced during its synthetic procedures as well as photocatalytic self-decomposition events. In this work, we introduce Sr into the B site of SrTaO2N to form a complex perovskite oxynitride, Sr3(Sr1/3Ta2/3)3O9−xNy (i.e. Sr4Ta2O9−xNy). The new compound has a much lower defect concentration compared to SrTaO2N and much higher stability against photocatalytic self-decomposition. More importantly, Sr4Ta2O9−xNy demonstrates significantly improved photocatalytic activity for water oxidation and reduction reactions under visible light irradiation (λ ≥ 400 nm) than SrTaO2N, approaching an apparent quantum efficiency as high as 3.4% at 420 ± 20 nm.
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
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 15
·2210578
·
IF 19
Guanghao Li,Suping Ma,Zhuo Li,Yawen Zhang,Yishu Cao,Yi Huang
Fe 3 GeTe 2 provides an ideal system for the study of itinerant ferromagnetism. However, the Curie temperature (Tc) below room temperature limits its further in-depth research and wide applications. Here, the Tc of 224 K for Fe 3 GeTe 2 is greatly increased to 496 K for Fe 3 GeTe 2 /FeTe 2 /Fe 3 Ge by temperature-induced self-decomposition doping, contributing to improve the electromagnetic response for enhancing the absorption strength and bandwidth and boosting application potentials at higher temperatures. Then, to achieve the multispectral compatible strong absorption, room temperature ferromagnetic dielectric graphene@Fe 3 GeTe 2 /FeTe 2 /Fe 3 Ge absorber with 3D porous network structure is prepared by synergistic self-assembly. It has high Tc of 443 K with strong electromagnetic synergistic loss, achieving reflection loss of −61 dB at 12.6 GHz. Moreover, its absorption loss in the terahertz band (0.1–1.6 THz) is 76 dB, and the average loss is greater than 50.4 dB. Furthermore, the absorber is very potential as stealth skin to efficiently reduce satellite RCS with a multi-angle and multi-band manner in the gigahertz and terahertz bands, thus achieving the purpose of stealth. Compared with the reported conventional absorbers, the absorber has a multispectral compatible strong absorption performance covering gigahertz and terahertz bands, thus very promising for electromagnetic protection of electromagnetic communication and space vehicles.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2023
·
IF 4.7
Weiqiang Hu,Lianfeng Wei,Jun He,Songhua Chen,Shaocun Liu,Zongqing Ma,Yongchang Liu
In this work, we creatively introduced MAX additives (Ti 2 AlC) into W alloy system to break the development bottleneck of ball milling technology: a large amount of oxygen impurities and large-sized second phase particles at grain boundaries (GBs). Unlike traditional oxides/carbides, Ti 2 AlC can undergo self-decomposition during high-temperature sintering stage (>1400 °C) on the basis of hydrogen sintering, and continue to adsorb a number of stubborn oxygen impurities to form various smaller, more dispersed, and stronger in-situ Ti x C y , TiO x , Al 2 O 3 , and Al x Ti y O z nanoparticles . Furthermore, these in-situ nanoparticles could maintain stable coherent interfaces with W, thereby more effectively refining, purifying, and strengthening matrix. Compared to traditional W-carbide/oxide alloys, MAX additives render our alloy with high hardness (521 ± 24 HV 0.2 ), a remarkable combination of high compressive strength (1262.9 ± 35.1 MPa) and large ductility (9.88%). This work provides a new perspective for the preparation of high-performance refractory metals and relevant engineering application.
研究领域:
材料科学
·
金属材料
·
纳米材料
·
粉末冶金
·
结构合金
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2019
·
IF 3.89
Jianzhong Wu,Yimin Cai,Mingqi Zhang,Jizhi Zhou,Xujie Zhou,Weikang Shu,Jia Zhang,Xin Huang,Guangren Qian,Yang Deng
In this study, ferrate intercalated Ca/Al-layered double hydroxide (Ferrate-LDH) was synthesized and characterized for water treatment . In the new Ferrate(VI) material, ferrate was stably present in the LDH interlayers , in agreement with results of the Density Functional Theory simulation. The oxidative capability of Ferrate-LDH was examined in terms of the mineralization of phenol in water. The Ferrate-LDH could achieve up to 86.8% utilization efficiency during oxidative destruction of phenol in water (pH = 6.5, TOC = 38.3 mg/L), advantageous over direct ferrate addition that only achieved 12.6% utilization efficiency. A slower evolution of dioxygen (a final product of Ferrate(VI) self-decay) was observed in the Ferrate-LDH water system, suggesting that the LDH structure inhibited Ferrate(VI) self-decay. Therefore, the better phenol removal achieved by Ferrate-LDH was likely ascribed to an increased oxidant exposure caused by the increased lifetime of Fe(VI) in water. Characterization of the LDH products before and after oxidation of phenol revealed that ferric (hydr)oxides capable of surface catalyzing Ferrate(VI) self-decay were formed on the LDH surface, not inside the LDH interlayers, suggesting that ferric(III), the product of Fe(VI) reduction, was repelled from the LDH interlayers. Isolation of Fe(VI) present in the LDH structure from these active iron products may be responsible for the inhibited Ferrate(VI) self-decay when Ferrate-LDH was dosed to water. This study demonstrates that the intercalation of ferrate in LDH represents a promising approach to more efficiently and economically utilizing Ferrate(VI) for the elimination of water pollutants .
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2024
·
IF 9.9
Rui Wang,Xue Zhou,Mingsheng Hao,Qiang Xu,Rongji Xu,Yinshi Li
The direct liquid fuel cell utilizing hydrogen peroxide as an oxidant is considered to be the promising energy conversion technology, owing to its superior energy density and theoretical voltage. In the hydrogen peroxide-based fuel cells, the ever-changing two-phase mass transport and multi-component reaction processes resulting from the hydrogen peroxide self-decomposition exerts a pivotal influence on their performance. In this work, taken hydrogen peroxide self-decomposition into account, a cross-dimensional multi-physics model for the hydrogen peroxide-based fuel cell was proposed and developed to clarify the complex mechanisms of transports and reactions. In this ingeniously developed model, the multi-component reaction in the porous electrode is elucidated by a two-dimensional (2D) sub-model, the two-phase mass transport in the flow field is captured by a three-dimensional (3D) sub-model, and the one-dimensional (1D) correlation equation is served as a bridge between them. The uneven distribution of gas–liquid volume, velocity and current density and their relationships in fuel cell with serpentine flow field and dot matrix flow field were thus achieved. Furthermore, a novel gradient dot matrix flow field was developed to match the two-phase mass transport and multi-component reaction processes of hydrogen peroxide-based fuel cell. It is found that the continuously increasing pressure and velocity along flow path is balanced by the gradient-downsized ribs and the formation of large-volume oxygen bubbles is prevented by the gradient-densified ribs, achieving obviously uniformized current density distribution. Moreover, the gradient dot matrix flow field enables 54 % higher average hydrogen peroxide coverage contents (49 %) and 86 % lower average pressure drop (172 Pa) compared to the serpentine flow field, yielding 6.3 % higher peak power density (210 mW cm −2 ) and ultra-low extra pump power in fuel cell. This work will make contribution towards gaining profound insights into the intricate mechanisms underlying mass and charge transport, and offering invaluable guidance for the flow field design for the hydrogen peroxide-based fuel cells.
研究领域:
能源科学
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化学工程
·
燃料电池技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Huijuan Wang,Chong Chen,Yupeng Chen,Hui Wan,Lin Dong,Guofeng Guan
N-doped porous carbons have been regarded as competitive candidates for CO 2 adsorption by virtue of tunable micropores and basic nitrogen sites. Herein, we synthesized the ultramicropore-enriched N-doped carbon by pyrolysis of polyethyleneimine-based polymer network which was formed by nucleophilic substitution reaction of polyethyleneimine and p-dichloroxylene. The precursor with evenly anchored amine groups on the surface and interior could not only serve as pore-forming agent by self-decomposition, but also generate abundant nitrogen sites to enhance the surface polarity. By adjusting carbonization temperatures (500, 600, 700 and 800 °C) and amounts of KOH activator, the texture properties and nitrogen contents of the N-doped porous carbons (denoted as CPDs) were tuned finely. Impressively, the CPD-600 pyrolyzed at 600 °C possessed large surface area (1638 m 2 /g), narrow-distributed ultramicropores (d < 0.7 nm) and high nitrogen content (6.16 wt%). The sufficient nitrogen species (especially pyrrolic-N) as the basic “CO 2 -philic” sites could strengthen the affinity of polar surfaces toward CO 2 molecules. Moreover, the well-developed ultramiropores offered restricted spaces that could capture CO 2 by superposition effect of Van der Waals’ force. These advantages endowed CPD-600 with high-performance of CO 2 uptake (4.92 mmol/g), CO 2 /N 2 (15/85, v/v) selectivity (31) and regenerability at 298 K and 1 bar. The rational design of polymer-derived porous carbons with tailoring structural and functional properties could be applied not only to CO 2 capture from gas mixtures but also to other advanced fields.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Ruiyang Xiao,Yifu Fu,Lu Bai,Chu Chu,Junye Ma,Zongsu Wei,Richard Spinney,Dionysios D. Dionysiou,Jiaxi Pu
Ascorbate (Asc) has long been known to be an antioxidant against reactive oxygen species (ROS) for cytotoxicity and human diseases. However, its reported reactivity with superoxide radical ( O 2 • − ), an important ROS involved in aerobic metabolism system, exhibits great discrepancy; its mechanistic mode of actions on the molecular level is also largely debatable. Here, we investigated the reaction of Asc and O 2 • − by a combination of experimental and theoretical approaches. The rate constant measured by a competitive technique method was determined to be 3.3 × 10 4 M −1 s −1 under physiological condition. Mechanistically, our theoretical result indicated that O 2 • − abstracts a hydrogen atom on the enolic hydroxyl group forming ascorbyl radical (Asc • ), which is unreactive with O 2 • − or Asc • itself. However, with different protonation state of Asc • ( i.e., AscH • ) in acidic environment, its reactivity was demonstrated to be significantly altered. AscH • can react with O 2 • − via hydrogen atom abstraction and single electron transfer and/or undergo self−disproportionation. These complementary results provided fundamental principles for the ecotoxicological function and environmental potentials of Asc against ROS.
研究领域:
化学
·
生物化学
·
环境科学
·
分子生物学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
He Ren,Jiexin Li,Gengqi Liu,Yaping Sun,Xingyue Yang,Zhen Jiang,Jingyu Zhang,Jonathan F. Lovell,Yumiao Zhang
The development of nanocarriers capable of codelivering antigens and immune-activating adjuvants is an emerging area of research and is relevant for cancer vaccines that target induction of antigen-specific CD8+ T-cell responses. Here, we report a system for delivery of short peptide antigens to dendritic cells for strong cellular immune responses, based on block copolymers chemically modified with a hydrophobic and self-immolative linker. After modification, micelles effectively and reversibly capture antigens and adjuvants via a covalent bond within several minutes in an aqueous solution. After uptake in antigen presenting cells, the polymer disulfide bond is cleaved by intracellular glutathione, leading to release of pristine antigens, along with the upregulated expression of costimulatory molecules. The induced antigen-specific CD8+ T cells have strong tumor cell killing efficacy in the murine B16OVA and human papilloma virus-E6/E7 subcutaneous and lung metastasis tumor models. In addition, delivery to lymph nodes can be imaged to visualize vaccine trafficking. Taken together, multifunctional self-immolative micelles represent a versatile class of a vaccine delivery system for the generation of a cellular immune response that warrants further exploration as a component of cancer immunotherapy.
研究领域:
癌症免疫疗法
·
纳米技术
·
免疫学
·
药学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2021
·
IF 9.811
Jiexin Li,He Ren,Yaping Sun,Gengqi Liu,Xingyue Yang,Qian Qiu,Yuanmeng Ding,Jonathan F. Lovell,Yumiao Zhang
Cancer peptide vaccines face challenges for antigen delivery and presentation. In the present work, we develop a self-assembled magnetic micelle delivery system for CD8+ T-cell epitopes that produces strong cellular immune responses. Hydrophobically modified imiquimod R837 and Zn1.15Fe1.85O4 are coencapsulated in the core of Pluronic F127 block copolymer micelles. Magnetic Zn1.15Fe1.85O4 enables externally targeted delivery and enrichment of micelles in lymph nodes. Furthermore, metal ions are found to enhance vaccine immunogenicity. F127 micelles were chemically modified by a self-immolative linker so that antigens are rapidly and reversibly grafted on micelles in an aqueous solution. With the assistance of an external magnetic field, once the magnetic micelles are delivered to lymph nodes and taken up by immune cells, intracellular glutathione cleaves the disulfide bond and releases pristine short peptide antigen. Delivery to lymph nodes is tracked by magnetic resonance and fluorescence imaging. The use of this vaccine system eradicated tumors in a murine tumor model. Thus, integrating multiple functionalities in a single micellar delivery system, including responsive linkage, multiple immunostimulatory molecules, targeted delivery, and bimodal imaging, demonstrates the potential for theranostic approaches to develop a new generation of cancer vaccines.
研究领域:
癌症研究
·
免疫学
·
纳米技术
·
生物医学工程
·
治疗诊断学
✓ 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）