JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Samuel Guemou,Liuting Zhang,Shuai Li,Yiqun Jiang,Tao Zhong,Zichuan Lu,Ren Zhou,Fuying Wu,Qian Li
The design of an excellent active catalyst to improve the sluggish kinetic and thermodynamic properties of magnesium hydride (MgH 2 ) remains a great challenge to achieve its practical application. In this study, a novel Ni-Nb/rGO nanocomposite catalyst was successfully prepared by one-spot hydrothermal and subsequent calcination methods. The novel Ni-Nb/rGO nanocomposite exhibits an exceptional catalytic effect on improving MgH 2 sorption properties. Specifically, the onset desorption temperature of MgH 2 + 10 wt% Ni-Nb/rGO composite is reduced to 198 °C, much lower than that of undoped MgH 2 (330 °C). Interestingly, the composite can release 5.0, 5.9, and 6.0 wt% H 2 within 10 min at 245, 260, and 275 °C, respectively. Furthermore, the dehydrogenated MgH 2 + 10 wt% Ni-Nb/rGO composite starts to absorb hydrogen even at room temperature with approximate 2.75 wt% H 2 uptake at 75 °C under 3 MPa H 2 pressure within 30 min and exhibits excellent stability by maintaining 6.0 wt% hydrogen content after 20 cycles at 300 °C. Chou's model suggests that the de/hydrogenation kinetics of Ni-Nb/rGO-modified MgH 2 switches from surface penetration model to diffusion model at lower temperatures. Additionally, the activation energies ( E a ) for the de/hydrogenation of MgH 2 + 10 wt% Ni-Nb/rGO are reduced to 57.8 kJ/mol and 33.9 kJ/mol, which are significantly lower than those of undoped MgH 2 . The work demonstrates that the addition of a novel ternary Ni-Nb/rGO catalyst is an effective strategy to not only boost the sorption kinetics of MgH 2 but also maintain its cycling property.
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
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yang Liu,Jia-Ji Liang,Wei-Ming Guo,Chao Chang,Xiao-Ming Duan,De-Chang Jia,Hua-Tay Lin
High-temperature thermal stability plays a crucial role in the structural application of pressureless liquid-phase sintered SiC (PLS-SiC) ceramics. In this paper, a PLS-SiC ceramic processed with CeO 2 –Al 2 O 3 as sintering additives with excellent high-temperature thermal stability was achieved by incorporating (Hf, Zr, Ta, Nb, Ti)B 2 (HEB) particles. Results showed that PLS-SiC ceramics with HEB-free underwent a structural change from dense to porous microstructure after annealing at 1800 °C/1 h. Conversely, PLS-SiC ceramics with the addition of 10 vol% HEB exhibited excellent thermal stability, as evidenced by the retention of their dense microstructure after exposure to annealing at 1800 °C/1 h. The possible primary reasons for this significantly different response to the thermal stability could be probably attributed to fact that HEB reacted with CeAlO 3 and SiC to form solid-phase products, subsequently inhibiting the formation of gas-phase products after decomposition of CeAlO 3 alone in a high-temperature vacuum environment. In addition, the formation of a compact protective outer layer containing Hf–Ta containing diboride in PLS-SiC ceramics during the annealing process could effectively hinder the volatilization of volatile substances at a high temperature.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2019
·
IF 2.752
Jingfeng Wang,Fei Jiao,Di Zhang,Meixia Chang,Lingbo Cai,Yunlong Li,Cao Wang,Shugang Tan,Qiang Jing,Bo Liu,Dong Qian
The relationship between the doping position of Nb in Bi 2 Se 3 and its superconductivity is investigated by XPS, magnetic measurement and transport measurement. It is found that for Nb x Bi 2 Se 3 , the main impurity phase comes from BiNbSe 3 . Superconducting volume fraction of Nb doped Bi 2 Se 3 increases with the ratio of Nb inserted in the van der Waals layers. The van der Waals-layer-position doped Nb may lead to superconductivity in Bi 2 Se 3 . This work may stimulate further investigation on topological superconductivity mechanism of Nb x Bi 2 Se 3 .
研究领域:
凝聚态物理
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Jingxuan Li,Yu Zeng,Yihang Fang,Nan Chen,Guoping Du,Aisheng Zhang
In this work, a sol-gel method was used to synthesize nanometer-sized rutile (La + Nb) co-doped TiO 2 powders, which were employed to prepare (La + Nb) co-doped TiO 2 ceramics. The average grain size of the (La + Nb) co-doped TiO 2 ceramics was less than 200 nm, which is much smaller than that of conventionally prepared co-doped TiO 2 ceramics generally having micron-sized grains. The effect of the (La + Nb) co-doping concentration on the microstructures and dielectric properties of the obtained ceramics was studied in detail. For a 2% co-doping concentration, it was found that the (La + Nb) co-doped TiO 2 ceramic had dielectric permittivity (εʹ) higher than 2 × 10 4 for frequency up to 1 MHz and the lowest dielectric loss (tanδ) was 0.019 at 1 kHz. The electron hopping and electron-pinned defect-dipole effect was considered as the main reasons for colossal permittivity and low tanδ. This work provides a technique for the synthesis of co-doped TiO 2 nanoparticles and preparation of submicron-grain-sized co-doped TiO 2 ceramics with good dielectric properties.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Yan Chen,Guojun Lv,Xuyang Zou,Shihao Su,Jiangzhang Wang,Chaoyi Zhou,Jialing Shen,Yangbin Shen,Zhongmin Liu
Dealuminated Beta zeolite has a large amount of silanol defects on its interface, which provides an ideal place for embedding metal species and creating metal active sites in a confined microenvironment. The confined metal sites as well as their surroundings are closely related to the reactant activation and transient state achievement. Hence, unraveling the confined metal sites is of great significance for the catalytic reaction process. Herein, niobium species were incorporated into the silanol defects over dealuminated Beta zeolite with a facile dry impregnation method, co-grinding the niobium precursor with dealuminated Beta zeolite support. The successful incorporation of niobium into the silanol defects for 30Nb-Beta zeolite was verified by DRIFT, 1 H MAS NMR, UV–Vis and UV-Raman characterizations. XAS characterization and DFT calculations further disclosed that the confined Nb species existed as (SiO) 2 Nb(OH)(=O), containing two Si−O−Nb bonds, one Nb=O bond as well as one Nb−OH bond. The synthesized 30Nb-Beta zeolite catalyst displayed a superior cyclohexene conversion of 51.1%, cyclohexene oxide selectivity of 83.1% as well as TOF value of 188.2 h −1 ascribed to the inherent electrophilicity of Nb(V) for confined (SiO) 2 Nb(OH)(=O) species as well as the low oxygen transfer energy barrier for Nb V −OOH species. Furthermore, the prepared 30Nb-Beta zeolite can be effectively employed to other cyclic alkene epoxidation reactions.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Mengran Li,Jialing Gu,Qinke Tang,Jiabao Bai,Bin Cui,Ruoyu Ma,Yunfeng Zhu,Rui Shi,Yao Zhang,Jiguang Zhang,Yana Liu,Jun Wang,Zhixin Ba,Xiaohui Hu
Magnesium hydride (MgH 2 ) is a highly promising solid-state hydrogen storage material, but its application is hindered by sluggish kinetics and high operating temperatures. Currently, alloying and catalysis are effective strategies for improving the hydrogen storage performance of MgH 2 , but the designing of a hydrogen ab/desorption system which synergistically combines them remains a challenge. Herein, Mg Al solid solution and intermetallic compounds (Al species), and a spherical Nb-doped TiO 2 (Nb-TiO 2 ) were introduced into Mg/MgH 2 to enhance the hydrogen storage performance. Al species significantly enhanced the dehydrogenation thermodynamics of Mg 90 Al 10 - 15 at.% Nb-TiO 2 , while improving the hydrogen ab/desorption kinetics of the composite synergistically with the Nb-TiO 2 . Density functional theory (DFT) calculations revealed that the synergism of Al species and Nb-TiO 2 led to preferential adsorption of H atoms at the interfaces of Nb-TiO 2 and Mg 17 Al 12 , with abundant electron transfer. The dehydrogenation enthalpy ( ΔH ) of Mg 90 Al 10 - 15 at.% Nb-TiO 2 decreased from 80.86 (MgH 2 ) to 69.05 kJ/mol, while its hydrogen desorption apparent activation energy ( E a ) decreased from 146.40 (MgH 2 ) to 88.80 kJ/mol simultaneously. The composite could absorb 4.70 wt% H 2 within 2000 s at 200 °C and showed a dehydrogenation onset temperature of 209 °C. This work reveals a synergistic effect between alloying and catalysis, advancing both the performance enhancement strategies and the mechanistic understanding of Mg-based hydrogen storage materials.
研究领域:
材料科学
·
氢储能
·
固态化学
·
计算材料学
·
纳米催化
·
能源材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ETHNOPHARMACOLOGY
·
2023
·
IF 5.4
Xueping Wei,Junsong Jing,Rongrong Huang,Ting Zhou,Lianhao Wu,Guoteng Ou,Youping Wu,Jingjin Hu,Wenwen Zhu,Yueguo Wu,Yuanyuan Li,Sheng Zhang,Zhenqiang You
Ethnopharmacological relevance Pulmonary fibrosis (PF) is an irreversible lung disease that severely affects human respiratory function. Traditionally, the natural plant Quzhou Fructus Arantii (QFA) has therapeutic effects on respiratory diseases. However, the effects and the mechanism of anti-fibrotic have not been elucidated. Aim of the study In this study, QFAE-nB was extracted from QFA, the aims of this study include understanding the correlation between Bleomycin (BLM)-induced PF and STING pathway in mice, as well as exploring the role and mechanisms of QFAE-nB in the treatment of PF. Materials and methods QFAE-nB was extracted from QFA, six main chemical components in QFAE-nB were identified by HPLC–QTOF–MS/MS, and quantitative analysis was conducted by HPLC. qPCR and Western blot were used to verify the molecular mechanism of QFAE-nB, and the anti-fibrotic effect of QFAE-nB was determined by hematoxylin-eosin (HE) staining and Masson staining as well as immunohistochemistry. TREX1-KO and STING-KO mice were used to verify the relationship between STING and PF and the important target action of QFAE-nB. Results Six main flavonoids in QFAE-nB were identified as eriocitrin (0.76%), neoeriocitrin (2.79%), narirutin (4.31%), naringin (35.41%), hesperidin (1.74%), and neohesperidin (27.18%). The results showed that BLM-induced PF was associated with its exacerbated release of proinflammatory factors and chemokines in lung tissues. In addition, QFAE-nB alleviated BLM-induced lung fibrosis in mice by inhibiting the activation of the STING signaling pathway and reducing the signal transduction of TBK1–IRF3 and TBK1–NF-κB pathways. Notably, knockout of the TREX1 gene caused massive inflammation and even induced PF in the lung tissues, whereas QFAE-nB effectively alleviated inflammation and reduced PF. The deletion of the STING gene suppressed BLM-induced PF and inflammation, but STING-KO mice treated with QFAE-nB showed even lower expression levels of proinflammatory factors and chemokine. Conclusions The STING pathway plays an important role in PF, and QFAE-nB alleviates PF by mainly targeting the inhibition of the STING pathway to reduce inflammation. Together, the study paves the way for targeting the STING pathway in PF treatment.
研究领域:
药理学
·
民族药理学
·
分子生物学
·
免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Fufeng Cai,Peijing Lu,Jessica Juweriah Ibrahim,Yu Fu,Jun Zhang,Yuhan Sun
Methanol steam reforming is regarded as a very promising process to generate H 2 suitable for fuel cells. Typically, the Pd-based catalysts can catalyze efficiently methanol steam reforming for hydrogen production . But their high selectivity to CO, a byproduct of methanol reforming reaction , severely limits their potential application. In this work, a series of Nb-modified Pd−Zr−Zn catalysts with different Nb loadings were prepared to study their catalytic activities with more focus on the role of Nb on Pd−Zr−Zn catalyst for methanol steam reforming. The prepared catalysts were fully analyzed by using various characterization techniques, for example, ICP , BET, SEM, XRD , H 2 -TPR, NH 3 -TPD, HRTEM , CO chemisorption , XPS, and Raman. The experimental results showed that an increase in Nb loading for the Nb-modified Pd−Zr−Zn catalysts led to a decrease of the methanol conversion and H 2 production rate. This was probably due to the decrease in the amount of oxygen vacancies on the catalyst surface . However, introduction of Nb into Pd−Zr−Zn catalyst increased the acid strength on the catalytic surface. The aldehyde species derived from methanol decomposition were readily transformed to HCOOH, thus yielding high selectivity to CO 2 for the Nb-modified Pd−Zr−Zn catalysts. Significantly, the addition of Nb to Pd−Zr−Zn catalyst facilitated the incorporation of Pd into the ZnO lattices, which led to the formation of Pd−Zn alloy. Consequently, the Nb-modified Pd−Zr−Zn catalysts exhibited significantly lower CO selectivity and production rate than the Pd−Zr−Zn catalyst. From the results, this work offers a new way to the rational design of selective methanol steam reforming catalysts to decrease the formation of byproduct CO.
研究领域:
催化化学
·
能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 37
·20982-20989
·
IF 2.936
Yinhua Lv,Bing Cai,Qingshan Ma,Zenghua Wang,Jingyue(Jimmy) Liu,Wen-Hua Zhang
Planar-structured perovskite solar cells (PSCs) have received tremendous attention due to their high power conversion efficiency (PCE), simple process and low-cost fabrication. A compact thin film of electron transport materials (ETMs) plays a key role in these PSCs. However, the traditional ETMs of PSCs, TiO2 nanoparticulate films, suffer from low conductivity and high trap state density. Herein, we exploited TiO2 nanospindles as a compact ETM in planar PSCs for the first time, and achieved an efficient device with a PCE of 19.1%. By optimization with Nb doping into the TiO2 nanospindles, the PCE of the PSC was further improved up to 20.8%. The carrier transfer and collection efficiency were significantly improved after Nb5+ doping, revealed by Mott–Schottky (MS) analysis, space charge limited current (SCLC), photoluminence (PL), time-resolved photoluminence (TRPL) spectra, electrochemical impedance spectra (EIS) and so forth. Moreover, the hysteresis behavior was effectively inhibited and the stability was significantly enhanced. This work may provide a new avenue towards the rational design of efficient ETMs for perovskite solar cells.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PLoS Neglected Tropical Diseases
·
2025
·Vol. 19
·期 1
·e0012769
·
IF 3.4
Wenmin Qi,Fei Shen,Chuyue Wang,Juan Wen,Xi Pan,Zhongying Zhao,Lihua Xiao,Yaoyu Feng,Dongjuan Yuan
Fatty acid and retinol binding proteins (FARs) are lipid-binding protein that may be associated with modulating nematode pathogenicity to their hosts. However, the functional mechanism of FARs remains elusive. We attempt to study the function of a certain FAR that may be important in the development of Nippostrongylus brasiliensis . Nb -FAR-1 was highly expressed throughout developmental stages by RNA-seq data and qPCR analyses, and Nb -FAR-1 was a secretory protein and abundant in the excretory-secretory products. Nb -FAR-1 could bind fatty acids and retinol. Fatty acid pattern of parasitic adults was more similar to rat intestine than to free-living L3s, indicating that N . brasiliensis may be dependent on the host to obtain fatty acids. Lentivirus-mediated RNAi was performed on L3s, resulting in a reduction in the expression of Nb - far-1 gene. Furthermore, these RNAi effects could be maintained in several generations. The offspring L3s in Nb - far-1 RNAi group had a reduction in lipid droplets within the subcuticle and the swelling of the perioral epidermis, accompanied with down-regulated expression of enzymes in amino acid and glycerolipid metabolism and glycometabolism for growth by RNA-seq data. Adults in Nb - far-1 RNAi group had the crumpled epidermis loosely attached to the basal membrane of body surface and the breakage of mouth epidermis, accompanied with a decrease in adult egg-shedding and an appearance of abnormal eggs. In vitro culture of eggs showed decreased efficiency of egg hatchability and larval development in the Nb - far-1 RNAi group. Transcriptomic analysis showed that interference with Nb - far-1 expression induced downregulated expression of major sperm protein and serpin for reproduction, and collagen for epidermis formation in adults, most of which were relatively high expression in adults but low expression in L3s in the WT group. Thus, Nb -FAR-1 may affect the reproduction, growth, and development of N . brasiliensis by regulating the level of lipids.
Fatty acid and retinol-binding protein 1 (FAR-1) is lipid-binding protein that may be associated with modulation of host immune responses and provide insights into nematode pathogenicity to their hosts. However, the role of FAR-1 protein on parasitic nematodes remains unclear. Nippostrongylus brasiliensis was employed to identify the characteristics of Nb - far-1 gene, its expression patterns, ligand binding properties and the functions associated with it. The secretory Nb -FAR-1 protein was found to be highly expressed in N . brasiliensis ESPs and demonstrated affinity for fatty acids and retinol. Interference with Nb - far-1 gene expression resulted in a reduction in the formation of lipid droplets in L3s, a decrease in a rate of adult egg-shedding, egg hatchability, and larval development. Therefore, we proposed that N . brasiliensis Nb -FAR-1 protein may serve as a causative agent in nematode growth, development, and reproduction by regulating the level of lipids.
研究领域:
寄生虫学
·
分子生物学
·
免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY
·
2024
·
IF 9
Deshi Yang,Jianpeng Huang,Zhipeng Hu,Shiqi Qin,Jiaxin Mu,Fengqiang Wang,Zhijun Zhang,Yanjun Xie,Shouxin Liu,Qingwen Wang
Catalytic fast pyrolysis (CFP) of lignin aiming monocyclic aromatic hydrocarbons (MAHs) is attractive. Five metal oxide catalysts (named c-Nb 3 Al x ) with different Nb/Al ratios, c-Nb, c-Al, c-Nb 3 Al 1 , c-Nb 3 Al 2 and c-Nb 3 Al 3 were synthesized and applied to CFP of lignin. Among these catalysts, c-Nb 3 Al 2 exhibits excellent deoxygenation ability and the highest selectivity for MAHs (77.0 %). The selectivity and deoxygenation capacity of c-Nb 3 Al 2 for MAHs were higher than H-ZSM-5 (25) as a control. It was attributed to the large external surface area (90 m 2 g -1 ), mesoporous structure (16.15 nm) and high acid amount (2.00 mmol NH 3 /g cat ) of c-Nb 3 Al 2 . The c-Nb 3 Al 2 has good stability and can be regenerated by simple calcination . The selectivity of the regenerated c-Nb 3 Al 2 for MAHs was still high at 70.1 %. Guaiacol was used to compare the difference in the deoxygenation capacity of c-Nb 3 Al 2 and H-ZSM-5.
研究领域:
化学工程
·
材料科学
·
催化
·
生物能源
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Lei Chen,Guangci Li,Mingjie Zhang,Da Wang,Shuangju Li,Chuanhui Zhang,Xuebing Li,Keng H. Chung
Catalytic deoxygenation of fatty acids to alkanes is an ideal route to produce biodiesel with high heating value . However, traditional transition-metal sulfide and noble metal catalysts are sulfide-contaminated, high cost, or easily poisoned. To overcome the above issues, this work developed a non-noble and sulfide-free reduced transition-metal composite Ni x Nb y O z , which was effective to selectively hydrogenate stearic acid , a typical fatty acid model compound, to diesel-range alkanes. By using a simple slurry method, reduced Ni x Nb y O z catalysts have been successfully prepared with an outstanding catalytic performance. The results showed that catalyst Ni 0.5 Nb 0.5 O z effectively converted stearic acid to n -alkanes with nearly 100% conversion and >99% n -alkanes selectivity at mild conditions (513 K and 3.5 MPa of H 2 pressure). Appropriate Nb species improved the dispersion of Ni species, which may supply more hydrogenation active sites. Two possible reaction routes of stearic acid were proposed, and the hydrogenolysis of stearyl stearate was confirmed as the rate-determining step based on the kinetics experiments. Because of moderate acidity of Nb species, the ratio of C 17 /C 18 alkane was not markedly affected by reaction conditions when the conversion of stearic acid was higher than 99%. Moreover, catalyst Ni 0.5 Nb 0.5 O z showed a high recycle ability and compatibility for other long-chain fatty acids, demonstrating that catalyst Ni 0.5 Nb 0.5 O z is a promising green catalyst for producing biodiesel from fatty acids.
研究领域:
催化化学
·
能源化学
·
绿色化学
✓ 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）