CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Junhui Wang,Jiajia Liao,Tongkun Zhu,Zhipeng Wang,Qiong Yang,Hongze Liu,Shijie Jia,Jin Huang,Sirui Zhang,Jiayi Hu,Jie Jiang,Limei Jiang,Yichun Zhou
Ferroelectric synaptic devices are pivotal in artificial intelligence applications, particularly for image recognition tasks. Their outstanding capabilities in neuromorphic information processing, biologically plausible signal emulation, and faithful neural mimicry render them indispensable. However, for HfO 2 -based ferroelectric synaptic devices, concurrently attaining high remnant polarization and rapid domain switching which are essential for high-speed processing and precise pattern recognition remains a formidable challenge. In this study, gradient Zn-doped HfCeO x (Zn: HCO) ferroelectric film was fabricated. It displays enhanced ferroelectric properties with a remnant polarization (2 P r ) reaching 77.2 µC/cm 2 . High-resolution transmission electron microscopy analyzes and phase-field simulations reveal that the gradient Zn doping induces a flexoelectric effect in HfCeO x thin films, which promotes the formation of the ferroelectric orthorhombic phase. Additionally, this gradient design accelerates domain switching speed by enhancing the domain wall mobility under applied electric fields. To demonstrate the neuromorphic computing potential, we implemented an artificial neural network using Pt/Zn: HCO/p + -Si synaptic devices, achieving an 86.5 % recognition accuracy in standard pattern classification tasks. This work establishes a viable strategy for simultaneously enhancing both ferroelectric polarization and switching speed in HfO 2 -based memory and neuromorphic devices.
研究领域:
材料科学
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微电子学
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纳米科技
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神经形态工程
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固态物理
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 17
·9985-9995
·
IF 3.119
Xiaomin Li,Zhengjiang Du,Yi Wu,Yadong Zhen,Rixin Shao,Bingqi Li,Chengmeng Chen,Quansheng Liu,Huacong Zhou
Construction and application of novel hydrogenation catalysts is important for the conversion of carbonyl or aldehyde compounds into alcohols in the field of biomass utilization. In this work, a novel, efficient, and easily prepared hafnium–graphite oxide (Hf–GO) catalyst was constructed via the coordination between Hf4+ and the carboxylic groups in GO. The catalyst was applied into the hydrogenation of biomass derived carbonyl compounds via the Meerwein–Ponndorf–Verley (MPV) reaction. The catalyst gave high efficiency under mild conditions. An interesting phenomenon was found whereby the activity of the catalyst increased gradually in the initial stage during reaction. The solvent, isopropanol, was proved to have an activation effect on the catalyst, and the activation effect varied with different alcohols and temperatures. Further characterizations showed that isopropanol played the activation effect via replacing the residual solvent (DMF) in micro- and mesopores during the preparation process, which was hard to be completely removed by common drying process.
研究领域:
催化化学
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生物质利用
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2023
·Vol. 11
·期 2
·564
·
IF 3.5
Shuai Li,Shenghai Yang,Pengfei Zhao,Yongming Chen,Chaobo Tang,Yanqing Lai,Chaoyong Deng,Changhong Wang
The electrodissolution-coupled hafnium alkoxide (Hf(OR)4, R is alkyl) synthesis (EHS) system, which has significant environmental and economic advantages over conventional thermal methods, serves as a promising system for green and efficient Hf(OR)4electro-synthesis. The EHS system is operated based on the simultaneous heterogeneous reactions of hafnium dissolution and ethanol dehydrogenation, as well as the spontaneous solution-based reaction of Hf4+and OR−. Employing green ethanol and Hf as feedstocks, the anodic hafnium corrosion/dissolution electrochemical behavior of the Et4NCl or Et4NHSO4based anhydrous system was investigated through electrochemical measurements combined with SEM observations. The results demonstrated that the Et4NCl-based anhydrous ethanol system exhibited an efficient mechanism of passive film pitting corrosion breakdown and metal hafnium dissolution, while the Et4NHSO4-based anhydrous ethanol system reflected the weak corrosion mechanism of the anodic hafnium under the passive film. The polarization resistance of the Et4NCl system was dramatically lower than that of the Et4NHSO4system, which indicated that the Et4NCl system had superior anodic hafnium corrosion performance compared to the Et4NHSO4system. Overall, the investigation of the electrochemical behaviors of anodic hafnium corrosion/dissolution provides theoretical guidance for the efficient operation of EHS electrolysis.Keywords:hafnium;anhydrous ethanol;tetraethylammonium chloride;tetraethylammonium bisulfate;electrocatalytic corrosion;mechanism;polarization resistance
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2022
·Vol. 105
·期 12
·7726-7740
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IF 4.186
Xuemeng Zhang,Jia Sun,Yuyu Zhang,Hejun Li
The SiHfOC ceramic microspheres were synthesized from the polysilazane and hafnium(IV) acetylacetonate hybrid precursors through a combination of hydrothermal method and polymer-derived ceramics (PDCs) method. The SiHfOC ceramic microspheres consist of β-SiC, SiO 2 , and m -HfO 2 in an amorphous SiOC matrix and are in a spherical morphology with an average size of about 2 μm. Hafnium-containing nanoparticles with ∼50-nm size are not only uniformly distributed on the surface of the ceramic microspheres but also embedded in the SiHfOC ceramic microspheres, forming a unique mosaic structure. Pyrolyzing at 1000°C offers a possibility of an in situ formation of nanocrystal nuclei in the amorphous SiOC ceramic matrix, and the subsequent annealing at 1500°C helps the small nanocrystal nuclei grow and separate the amorphous SiHfOC into a multiphase SiOC network containing β-SiC, SiO 2 , m -HfO 2 nanocrystalline and free C. This research provides a methodology for preparing multicomponent ceramic microspheres that can efficiently develop high-performance PDCs modified by transition metal alkoxide.
研究领域:
材料科学
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陶瓷
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2019
·
IF 3.45
Chun Li,Yue Ma,Jian He,Hongbo Guo
Sandwich structure of cubic (C) phase/monoclinic (M) phase/C phase was formed in 8% mol Y 2 O 3 partially stabilized HfO 2 (Hf 0.92 Y 0.08 O 1.96 , YSH8) samples which were produced by sintering of YSH8 green body cold pressed from nano-powders of C phase at 1500 °C. The geometry of the sandwich structure was approximately tailored by controlling the sintering time. The YSH8 samples with sandwich structure from nano-powders yielded fracture toughness of 2.1–2.4 MPa m 0.5 , which was about 33% higher than that of conventional YSH8 sample sintered from micron powders. Both the experimental results and numerical simulation indicated that the fracture toughness is closely related to the geometry of the sandwich structure.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2023
·Vol. 25
·期 46
·6489-6495
·
IF 3.1
Yali Ma,Haitang Wang,Hailong Wang,Jiani Wang,Shuaiyu Jiang,Qiang Zheng,Songyan Jia,Xue Li,Tianyi Ma
By utilizing a winding carboxylic acid ligand as the linker and 12-connected Hf6 clusters as the metal node, we successfully construct a novel hafnium-based metal–organic framework [Hf6O4(OH)4(DCPB)6]·(Hf-MOF, 1,3-di(4-carboxyphenyl)benzene (H2DCPB)) with ultra-microporous structure. Benefitting from the strong coordination bond between Hf6 clusters and the carboxylic acid ligand, the synthesized Hf-MOF displays extraordinarily high thermal and chemical stability, in which the Hf-MOF can maintain high crystallinity under both acidic and basic aqueous solutions, and its decomposition temperature is as high as about 400 °C. Moreover, the interpenetrated framework can endow the Hf-MOF with ultra-microporous pores, which can provide multiple adsorption sites and play a role in the size sieving effect of CO2 molecules. Thus, the Hf-MOF displays excellent CO2 adsorption and separation performance, in which the maximum CO2 adsorption amount can reach up to 65.5 cm3 g−1 at 273 K and 1 bar, and the selectivities for CO2/CH4 = 0.5/0.5 and CO2/CH4 = 0.05/0.95 are as high as 6.9 and 6.0 under 1 bar at 298 K, respectively, and surpass many reported water stable MOF materials. The commendable stability and the CO2 adsorption/separation ability are of extreme importance for its practical industrial applications.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Li Jing,Lingwei Yang,Yanxiang Liang,Sijia Shen,Jun Zhang,Liping Liu,Changhao Zhao,Haojun Ma,Guolin Wang
Ceramic matrix composite is widely applied in thermal protection system (TPS) of space vehicles to resist ultrahigh temperature aerodynamic heating. In this work, a novel carbon fiber reinforced hafnium carbide matrix composite (C f /HfC) is fabricated, and its potential serving as TPS material is studied inside an inductively coupled plasma wind tunnel. The oxidation mechanism of the as-fabricated C f /HfC is thus revealed in the dissociated air flows with different heat fluxes, based on the temperature profiles and the microstructural evolutions of HfO 2 oxide scale. The results suggest a transition in the oxidation activity of C f /HfC at 1650–1700 °C in reduced pressure (<10 kPa), from reaction-control to diffusion-control, due to the accumulation of porous HfO 2 oxide scale. When its thickness beyond a critical value, inner diffusions of oxidized species dominate the oxidation activity of C f /HfC. The thicker the HfO 2 is, the weaker the oxidation of C f /HfC can be in dissociated air plasmas. The oxidation mechanism endows C f /HfC with an excellent thermal protection property at ultrahigh temperatures (≥2000 °C). However, when the oxidation temperature ≥2700 °C, due to strong melt and evaporation, the continuity of HfO 2 is interrupted, which results in degradation of the oxidation blockage ability. As a result, C f /HfC is strongly ablated in the dissociated air plasmas. This infers that C f /HfC can be applied in TPS by preventing strong melt and dissipation of HfO 2 , and it is suggested to control the surface temperature of C f /HfC lower than 2700 °C in reduced pressures. This work may forward the advance of the novel material in the TPS of future space vehicles.
研究领域:
航空航天材料科学
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高温材料研究
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产品关联
DOI
高影响因子
Nano Express
·
2020
·Vol. 1
·期 3
·030006
·
IF 0
Farooq Ahmad,Tahir Muhmood,Asif Mahmood
Nanoparticles (NPs) are extensively being used in state-of-the-art nano-based therapies, modern electronics, and consumer products, so can be released into the environment with enhancement interaction with humans. Hence, the exposures to these multifunctional NPs lead to changes in protein structure and functionality, raising serious health issues. This study thoroughly investigated the interaction and adsorption of catalase (CAT) with HfO2-NPs by circular dichroism (CD), Fourier transform infrared (FTIR), absorption, and fluorescence spectroscopic techniques. The results indicate that HfO2 NPs cause fluorescence quenching in CAT by a static quenching mechanism. The negative values of Vant Hoff thermodynamic expressions (ΔHo, ΔSo, and ΔGo) corroborate the spontaneity and exothermic nature of static quenching driven by van der Waals forces and hydrogen bonding. Also, FTIR, UV-CD, and UV–visible spectroscopy techniques confirmed that HfO2 NPs binding could induce microenvironment perturbations leading to secondary and tertiary conformation changes in CAT. Furthermore, synchronous fluorescence spectroscopy confirmed the significant changes in the microenvironment around tryptophan (Trp) residue caused by HfO2 NPs. The time depending denaturing of CAT biochemistry through HfO2-NPs was investigated by assaying catalase activity elucidates the potential toxic action of HfO2-NPs at the macromolecular level. Briefly, this provides an empathetic knowledge of the nanotoxicity and likely health effects of HfO2 NPs exposure.
研究领域:
生物化学
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纳米毒理学
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环境科学
✓ 已验证
DOI
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Bo Tang,Shuang Li,Wei-Chao Song,En-Cui Yang,Xiao-Jun Zhao,Naijia Guan,Landong Li
FAU-type hafnosilicate zeolite with a hierarchical structure (Hf-USY) was constructed through a post-synthesis strategy containing the controlled dealumination of the commercial H-USY zeolite and the subsequent dry impregnation of the Cp2HfCl2 precursor. The incorporation of Hf ions into the zeolite framework involved the interaction between the silanol groups from framework dealumination and Cp2HfCl2 molecules. Characterization results from UV–vis and X-ray photoelectron spectroscopy verified that the incorporated Hf ions mainly existed in the tetrahedrally coordinated form in the zeolite framework. The creation of Lewis acid sites associated with Hf incorporation was confirmed by Fourier transform infrared spectroscopy with pyridine and deuterated acetonitrile adsorption. The as-synthesized Hf-USY zeolite served as a highly efficient catalyst in the transfer hydrogenation of ethyl levulinate to γ-valerolactone, outperforming the Sn- and Zr-silicate analogues. The Hf-USY catalyst also exhibited good performance in the transfer hydrogenation of more challenging substrates such as furanic, aromatic, as well as alkene-substituted carbonyl compounds into the corresponding alcohols. The influence of Lewis acid sites, preparation parameters, as well as the hydrogen donor on the catalytic activity of the Hf-USY zeolite was investigated in detail.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2022
·
IF 18.027
Ruoyao Li,Yuanyuan Fan,Lulu Liu,Hongna Ma,Deyan Gong,Zhaohua Miao,Hua Wang,Zhengbao Zha
The exciting success of NBTXR3 in the clinic has triggered a tumult of activities in the design and development of hafnium-based nanoparticles. However, due to the concerns of nondegradation and limited functions, the biomedical applications of Hf-based nanoparticles mainly focus on tumors. Herein, tannic acid capped hafnium disulfide (HfS2@TA) nanosheets, a 2D atomic crystal of hafnium-based materials prepared by liquid-phase exfoliation, were explored as high-performance anti-inflammatory nanoagents for the targeted therapy of inflammatory bowel disease (IBD). Benefiting from the transformation of the S2–/S6+ valence state and huge specific surface area, the obtained HfS2@TA nanosheets were not only capable of effectively eliminating reactive oxygen species/reactive nitrogen species and downregulating pro-inflammatory factors but also could be excreted via kidney and hepatointestinal systems. Unexpectedly, HfS2@TA maintained excellent targeting capability to an inflamed colon even in the harsh digestive tract environment, mainly attributed to the electrostatic interactions between negatively charged tannic acid and positively charged inflamed epithelium. Encouragingly, upon oral or intravenous administration, HfS2@TA quickly inhibited inflammation and repaired the intestinal mucosa barrier in both dextran sodium sulfate and 2,4,6-trinitrobenzenesulfonic acid induced IBD models. This work demonstrated that ultrathin HfS2@TA atomic crystals with enhanced colon accumulation were promising for the targeted therapy of IBD.
研究领域:
纳米技术
·
材料科学
·
药学
·
生物医学工程
·
胃肠病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CELLULOSE
·
2025
·
IF 4.8
Liu Wanni,Shi Xian,Liu Dongqi,Xing Xinyi,Ruan Mengya,Sun Song,Lyu Gaojin,Xu Siquan
Converting glucose-based carbohydrates such as microcrystalline cellulose and cellulose components in lignocellulose into 5-hydroxymethylfurfural (HMF) is a feasible way to achieve high-value utilization of biomass. To this end, this work assembled a series of bifunctional (x)Hf/SBA-15-S catalysts by introducing active hafnium species and grafting sulfonic acid groups onto the mesoporous SBA-15 silica carrier to drive the conversion of glucose, cellulose and untreated wheat straw into HMF. Through detailed parameter evaluation, competitive HMF yields were achieved from glucose (74%) and cellulose (51%), respectively. More importantly, the cellulose and hemicellulose components in untreated wheat straw could be efficiently converted simultaneously to obtain HMF and furfural with yields of 50 and 30%, respectively. Systematic characterization revealed that (x)Hf/SBA-15-S catalysts had an ordered pore channel, bifunctional acidity and good hydrothermal stability, which were beneficial to the process of cellulose undergoing depolymerization, isomerization and dehydration to produce HMF. Therefore, it is believed that the catalytic transformation strategy presented in this study has application prospects for realizing the utilization of glucose-based carbohydrates.
研究领域:
催化化学
·
生物质转化
·
绿色化学
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Shuai Ma,Fan Yang,Fengzhi Tan,Meiying Xie,Shuwen Yu,Liyan Xue,Zhiwan Li,Tianxi Hu
Nuclear-grade zirconium (Zr) and hafnium (Hf) play an inevitably strategic role in the sustainable development of the nuclear industry. However, the efficient separation of Zr ions and Hf ions is still problematic due to their approximate ionic radii. This work, provides a novel strategy for separating Zr ions and Hf ions by solvent extraction using an HCl solution containing the green amic acid N, N-di-2-ethylhexyl diglycolamic acid (D2EHDGAA). The results demonstrated that D2EHDGAA in HCl solution presented excellent separation performance for Zr ions and Hf ions. The separation factor (β Zr/Hf ) in the simulation liquid was 11.4, and that in the zirconium oxychloride hydrolysate was 34.5 at an HCl concentration of 2.5 mol/L. In addition, the slope method shows that the concentration of Cl - in the feeding water phase plays a controlling role in the separation of Zr ions and Hf ions. Compared with HCl, HNO 3 and ultrapure water, stripping can reach 94.3% at a H 2 SO 4 concentration of 0.1 mol/L. Hopefully, the new environmentally friendly D2EHDGAA-HCl system can match the methyl isobutyl ketone (MIBK)-HSCN system for efficient and selective extraction of Zr and Hf ions and show optimistic application prospects in industry.
研究领域:
化学工程
·
材料科学
·
核工程
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）