CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Wenyan Huang,Yufeng Wang,Zhonghao Ning,Shengjian Mao,Zhichao Xue,Yeqi Zhu,Qianwen Tao,Siqi Lan,Rongqian Yao
Making lightweight SiC composite ceramics with good load-bearing and remarkable surficial antioxidant capacity for use in thermal protection system is challenging. In this contribution, an ingenious strategy is reported to produce SiC(Mo x , rGO) nanocomposite polymer-derived ceramics (PDCs) for the first time by reactively re-pyrolyzing flexible polymolybdenumcarbosilane-vinyltriethoxysilane-graphene oxide (PMVG)/rigid SiC(Mo x , rGO) p fillers blends. Highly cross-linked PMVG precursors connect up to five polycarbosilane (PCS) to optimize their formability. In-situ formed MoSi 2 and Mo 4.8 Si 3 C 0.6 , compatible with β-SiC/SiO x C y /C free (rGO) matrix, can effectively strengthen interface bonding, promote nailing cracks, and even hinder β-SiC grain growth. More interestingly, using in-situ SiC nanowires (SiC nws ) by Mo-containing catalyst to decorate samples is an efficient route to reinforce the ceramic network, and SiC nws /SiC(Mo 0.1 , rGO) nanocomposite PDCs display optimal Vickers hardness (5.19 GPa), enhanced fracture toughness (4.26 MPa·m 1/2 ), high compressive strength (151.73 MPa), and low linear shrinkage (4.75%). Such products remain stability/integrity under flame scouring, their surface is covered by a dense SiO 2 passivation layer with good self-healing capacity owing to unique non-destructive oxides of embedded MoSi 2 /Mo 4.8 Si 3 C 0.6 . This work can further provide a feasible way to overcome the critical fabrication process in lightweight porous PDCs with well-balanced high load-bearing and good thermal insulation integration for aerospace vehicle components.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Yucheng Liu,Hantao Du,Xu Huang,Mingming Yin,Hongtao Liu,Haoran Sun,Lizhang Wang
The treatment of high-salinity organic wastewater (HSOW) poses severe challenges, with sulfate ions (SO 4 2− ) playing a critical role in electrocatalytic oxidation processes. In this study, a series of Ti/RuO 2 -MO x electrodes were fabricated by coating composite metal oxides onto titanium substrates, and the SO 4 2− -mediated electron transfer mechanism on the electrode surface was elucidated. We reveal that surface metal atoms form M O S electron channels with SO 4 2− , facilitating direct electron transfer for organic oxidation. The oxidation state of metal ions exerts a significant regulatory effect on electron transfer processes. Specifically, composite formation with metal oxides (i.e., Sn 4+ , Ce 4+ , Mn 4+ ) exhibiting valence state matching with Ru 4+ optimizes surface electron distribution, expands electron channels, and enhances SO 4 2− adsorption stability, thereby exerting a positive promotional effect on electron transfer. Conversely, composite systems involving metal oxides with significant valence state discrepancies from Ru 4+ (i.e., Cu 2+/3+ , Co 2+/3+ , Fe 2+/3+ ) disrupt surface electron distribution, shrink electron channels, and reduce SO 4 2− adsorption stability, leading to impaired charge transfer kinetics. Notably, via the SO 4 2− -mediated electron transfer process, the Ti/RuO 2 -SnO 2 electrode with outstanding electron transfer properties achieved ultra-low energy consumption (0.0022 kwh‧g −1 ) degradation of organic pollutants, with a carbon footprint of 0.68 kg CO 2 ‧m −3 . This study provides novel insights for the ultra-low energy treatment of HSOW.
研究领域:
环境科学
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电化学
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废水处理
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材料科学
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产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2017
·Vol. 19
·期 44
·6644-6650
·
IF 3.474
Ying-Jie Jia,Yi-Gang Chen,Xiao-Ni Yao,Xian-Ming Zhang
A series of alkali earth cadmium selenites including MgCd3(SeO3)4 (1), Ca0.7Cd2.3(SeO3)3 (2), SrCd(SeO3)2 (3) and BaCd(SeO3)2 (4) are synthesized by hydrothermal reaction and studied in detail by single crystal and powdered X-ray diffractions, thermal analyses, IR and UV spectral measurements and dipole moment calculation. 1 features a 3D anionic [Cd3(SeO3)4]2− framework constructed from isolated SeO3 trigonal pyramids and 2D [Cd3O12]n layers, in which the [Cd3O12]n layer is composed of edge-shared [Cd2O10]16− dimers and butterfly-like [Cd4O20]32− tetramers. 2 shows a smooth 2D [Cd2(SeO3)3]n layer composed of unique [Cd(SeO3)]n double chains. 3 exhibits a wavelike 2D [Cd(SeO3)2]n layer constructed from corner-shared CdO6 octahedra and isolated SeO3 trigonal pyramids. 4 displays a windmill-like 1D [Cd(SeO3)2]n chain built from zigzag [CdO4]n chain motifs and isolated SeO3 trigonal pyramids. The alkali earth oxide motifs demonstrate interesting and regular changes from isolated MgO6 octahedra, CaO7 polyhedra, and SrO9 tri-capped trigonal prisms based on a ribbon chain to BaO12 icosahedra based on a brucite-like layer, and meanwhile the SeO3 groups are observed from variable tetradentate to hexadentate coordination modes. These flexible motifs reveal that cadmium selenites are strongly affected by the size of the alkali earth cations, providing a feasible approach to modulating their space structure via selection of template cation.
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 37
·22780-22788
·
IF 3.361
Xiaoyi Sun,Qingjie Liu,Shuai Liu,Xintang Zhang,Shanshan Liu
A series of MOx–Cr2O3–La2O3/TiO2–N (M = Cu, Fe, Ce) catalysts with nitrogen doping were prepared via the impregnation method. Comparing the low-temperature NH3-SCR activity of the catalysts, CeCrLa/Ti–N (xCeO2–yCr2O3–zLa2O3/TiO2–N) exhibited the best catalytic performance (NO conversion approaching 100% at 220–460 °C). The physico-chemical properties of the catalysts were characterized by XRD, BET, SEM, XPS, H2-TPR, NH3-TPD and in situ DRIFTS. From the XRD and SEM results, N doping affects the crystalline growth of anatase TiO2 and MOx (M = Cu, Fe, Ce, Cr, La) which were well dispersed over the support. Moreover, the doping of N promotes the increase of the Cr6+/Cr ratio and Ce3+/Ce ratio, and the surface chemical adsorption oxygen content, which suggested the improvement of the redox properties of the catalyst. And the surface acid content of the catalyst increased with the doping of N, which is related to CeCrLa/TiO2–N having the best catalytic activity at high temperature. Therefore, the CeCrLa/TiO2–N catalyst exhibited the best NH3-SCR performance and the redox performance of the catalysts is the main factor affecting their activity. Furthermore, in situ DRIFTS analysis indicates that Lewis-acid sites are the main adsorption sites for ammonia onto CeCrLa/TiO2–N and the catalyst mainly follows the L–H mechanism.
研究领域:
催化
·
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yufa Feng,Xuefeng Zhang,Youxiang Shao,Xiaodong Chen,Huize Wang,Junhao Li,Ming Wu,Huafeng Dong,Quanbing Liu,Hao Li
Rational construction of inexpensive, highly efficient, and stable catalysts for ammonia borane (AB) methanolysis is in high demand but still remains a great challenge. In this work, we have successfully fabricated uniform Mox–Ni0.8Cu0.2O nanowires using a simple hydrothermal method followed by a post-calcination treatment and flexibly modulated the acidity of their surface by changing the amount of Mo introduced into Ni0.8Cu0.2O. The Mo0.1–Ni0.8Cu0.2O catalyst displayed strong catalytic activity toward AB methanolysis with an ultrahigh turnover frequency of 46.9 molH2 molcat.–1 min–1, which is even higher than some noble metal catalysts. In this work, an equation regarding the relationship between the quantity of moderated acid sites of catalysts and its corresponding activity toward AB methanolysis was first determined. A plausible mechanism for AB methanolysis catalyzed by Mox–Ni0.8Cu0.2O was proposed, and the benefits of the introduction of MoO3 to Ni0.8Cu0.2O for enhancing the catalytic performance were also discussed. These findings can form a basis for the rational construction of inexpensive catalysts with robust performance toward AB methanolysis for hydrogen production.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Ping She,Heng Rao,Buyuan Guan,Jun-sheng Qin,Jihong Yu
Efficient charge separation can promote photocatalysis of semiconductors. Herein, a hollow-structured TiO2 sphere decorated with spatially separated bifunctional cocatalysts was designed, which exhibited enhanced photocatalytic hydrogen generation. Ultrasmall-sized MOx (M = Pd, Co, Ni, or Cu) nanoparticles (NPs) were first introduced into a zeolite via confinement synthesis, and then, hollow TiO2 was fabricated by using the zeolite as a sacrificial template forming MOx@TiO2. Finally, Pt NPs were decorated on the outer shell, giving rise to MOx@TiO2@Pt, in which the MOx NPs and Pt NPs acted as hole capturers and electron sinks, respectively. Thanks to the enhanced light harvesting of the hollow structure and improved charge separation induced by the smaller-sized cocatalysts as well as spatially separated bifunctional cocatalysts, the as-prepared PdOx@TiO2@Pt catalyst exhibited a superior photocatalytic hydrogen-generation property (0.45 mmol h–1). This work demonstrates the advantage of the spatially separated bifunctional cocatalysts in enhancing the photocatalytic properties of semiconductors.
研究领域:
材料科学
·
催化
·
纳米技术
·
能源材料
·
光化学
✓ 已验证
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2026
·
IF 2.6
Jiming Wang,Min Ji,Min Wang
The integration of photocatalysis and thermal catalysis offers a sustainable route to drive the dry reforming of methane (DRM) at low temperatures, addressing the high energy consumption of traditional thermocatalytic processes. Herein, we systematically explore the effects of doping rare earth elements (Ce, Pr, and Y) on the photothermal catalytic activity and stability of Ni-based catalysts (Ni–MOx–Al2O3) for DRM. Results demonstrate that Ce doping significantly enhances charge carrier separation efficiency and reduces interfacial impedance, endowing Ni–Ce–Al with superior photocatalytic activity compared to Ni–Pr–Al and Ni–Y–Al catalysts. After 100 h of continuous reaction at 650 °C, the conversions of CH4 and CO2 only decrease from 59.0% and 62.0% to 52.6% and 56.8%, respectively. Mechanistic studies reveal that Ce incorporation increases the density of surface oxygen vacancies, which promotes the activation of CH4 and CO2 and enhances coke resistance under light conditions. Kinetic analysis confirms that Ni–Ce–Al possesses the lowest activation energies for CH4 (40.6 kJ mol−1) and CO2 (36.7 kJ mol−1) dissociation under illumination. This work provides helpful guidance for the design of high-performance Ni-based photothermal catalysts for DRM through rare earth modification, highlighting the crucial role of Ce in optimizing electronic properties and anti-coking ability.
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Yiqing Zeng,Zihua Wu,Lina Guo,Yanan Wang,Shule Zhang,Qin Zhong
The problems of easily inactivated by SO 2 poisoning and high N 2 O formation for MnO x based catalysts hinder its application in selective catalytic reduction (SCR) of NO x with NH 3 . The SO 2 poisoning mechanism has been well demonstrated, but the N 2 O formation mechanism was still controversial due to previous limited study. Herein, MnO 2 supported on MO x (Mn/M, M = Al, Si and Ti) were prepared by wet impregnation method to investigate the carrier effect on the formation of N 2 O. Although all of selected supports had a large amount of surface acid sites, only forming strong active-support interaction can separate the activation sites of NH 3 and NO + O 2 . Accordingly, the activation of NH 3 and NO + O 2 on MnTi was respectively occurred on TiO 2 and MnO 2 , but both NH 3 and NO + O 2 was activated on MnO 2 over MnAl and MnSi samples. The over-activation (NH 2 dissociated into NH) of NH 3 would be effectively inhibited when NH 3 activation was occurred on TiO 2 , thus it can significantly suppress the formation of N 2 O. In contrast, the NH 3 species would sharply decompose into NH on MnO 2 and then lead to the high amount of N 2 O. Finally, we proposed some methods that might effectively improve the selectivity of MnO x- based catalysts.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
MATERIALS & DESIGN
·
2021
·
IF 7.991
Chengzhe Gao,Zongliang Wang,Zixue Jiao,Zhenxu Wu,Min Guo,Yu Wang,Jianguo Liu,Peibiao Zhang
The overall aim of the current study is to develop a dual-functional PEEK implant to simultaneously fight off bacterial contamination and promote osseointegration by sustained release of moxifloxacin hydrochloride (MOX) and osteogenic growth peptide (OGP) from mussel-inspired polydopamine (PDA)-coated porous sulfonated PEEK (SPK) surface. Our study revealed that the MOX/OGP PDA-modified SPK (SPD-MOX/OGP) surface exhibited a durable and excellent antibacterial effect against planktonic/adherent Staphylococcus aureus and Escherichia coli in vitro . A remarkable enhancement in specific cell adhesion, proliferation and osteogenicity were observed on the SPD-MOX/OGP substrate due to the presence of OGP and PDA molecules compared to all other groups. More significantly, using the infected and non-infected rat tibia models confirmed the in vivo antimicrobial and osteogenesis abilities of SPD-MOX/OGP. Therefore, we are confident that such dual-functional PEEK surface with both antibacterial and osseointegrative capacities in this study would give a positive answer to periprosthetic joint infection-related issues.
研究领域:
生物材料
·
生物医学工程
·
骨科
·
传染病
✓ 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）