IONICS
·
2023
·Vol. 29
·期 3
·1221-1228
·
IF 2.8
Qi Min,Wang Xiangnan,Shu Hui,Dong Yihang
(8YSZ) 1− x (Cr 2 O 3 ) x ( x = 0, 0.05, 0.10, 0.15) are prepared by the co-precipitation method. Diffraction peaks of the samples belonged to the cubic fluorite structure. Conductivity decreases first and then increases with increasing Cr 2 O 3 content. An oxygen sensor based on 8YSZ solid electrolyte and (8YSZ) 0.85 (Cr 2 O 3 ) 0.15 diffusion barrier is prepared by the Pt slurry bonding method. The sensor has a limiting current plateau at 2% oxygen concentrations within 720 ~ 870 °C. The oxygen sensor has a linear relationship between the log I L and 1000/ T . At 850 °C, a linear relationship between the limiting current I L and oxygen concentration x (O 2 ) is established for the oxygen sensor. The oxygen sensor is provided with a limiting current plateau within the experimental concentration division, and the limiting current plateau is not affected by x (CO 2 ) and p (H 2 O). I-V curves of the oxygen sensor overlap, and the limiting current plateaus are almost equal under the long-term high-temperature operating conditions of 144 h.
研究领域:
材料科学
·
传感器技术
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Fengfeng Chen,Kui Shen,Yitao Yang,Haigen Huang,Yingwei Li
The facile fabrication of porous solid acids is highly desired for replacing hazardous liquid acids for many acid-catalyzed reactions in the industry. Herein, we present a bottom-up strategy to construct ultrastable mesoporous Cr2O3/SiO2 nanohybrids (denoted as Meso-Cr–Si–O) with highly dispersed Lewis acid sites by pyrolysis of a SiO2@MIL-101 precursor prepared via nanocasting by a reverse double-solvent approach, which can guarantee the efficient encapsulation of SiO2 nanoparticles (NPs) inside the MIL-101 pores. The pore environment of Meso-Cr–Si–O can be well tuned by simply controlling the amount of silica within the MIL-101 pores and the pyrolysis temperature. Pyridine adsorption experiments demonstrate that the density of Lewis acidic sites in the obtained Meso-Cr–Si–O is much higher than that of MIL-101-derived Cr2O3 NPs. Benefitting from its highly mesoporous nanostructure with abundant acid sites, the optimal Meso-Cr–Si–O exhibits a significantly improved catalytic activity for the Lewis-acid-catalyzed Meerwein–Ponndorf–Verley reduction of cyclohexanone with 4.5 times higher yield of cyclohexanol than that of the MIL-101-derived Cr2O3 NPs, representing the first efficient Cr2O3-based catalytic system for this reaction.
研究领域:
化学
·
催化科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Bingying Gao,Jinyao Cao,Chao Yao,Linqiang Mao
Advanced aerogel materials with lightweight, flame retardant, and rapid cooling properties are urgently needed as thermal insulators in harsh environments. Herein, Cr 2 O 3 − Al 2 O 3 aerogels (CrAAs) were fabricated through a simple method and an ambient pressure drying process. A large number of pores were produced in the microstructure of the sample by the carbonization of soluble starch during calcination. The porous structure decreases the density of the prepared CrAA (Cr 2 O 3 − Al 2 O 3 aerogel) to as low as 0.143 g cm −3 , and increases the thermal conductivity to as high as 0.125 W m −1 K −1 , indicating the good thermal dissipation and rapid cooling performance of the sample. The prepared CrAAs possess a variety of composite properties such as good flame retardancy, rapid cooling, and colour restore after flame is extinguished. Moreover, after being subjected to flame treatment at ∼ 1300 °C using a butane blowtorch for 5 min, the CrAAs can be rapidly cooled to about 39.2 °C in about 1–2 min. The mechanism of the rapid cooling property was herein analysed, and we anticipate the potential application of CrAAs in flame–retardant cooling coatings.
研究领域:
材料科学
·
热工程
·
化学工程
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DOI
高影响因子
Energetic Materials Frontiers
·
2022
·
IF 0
Guang-pu Zhang,Yu-hang Cheng,Miao-miao Li,Lei Xiao,Hu Guo,Wei Jiang,Ga-zi Hao
In this study, CuO–Cr 2 O 3 –PbO ternary nanocomposites (TNCs) with different atomic ratios of Cu:Cr:Pb (5:2:8, 5:4:6, 5:6:4, 5:8:2) were synthesized by means of efficient mechanical milling. As confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), uniform and impurity-free CuO–Cr 2 O 3 –PbO TNCs with an average grain size of 30 nm were successfully obtained. The catalytic properties of CuO–Cr 2 O 3 –PbO TNCs favorable for the pyrolysis of ammonium perchlorate (AP) were studied through thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). The results show that TNC-8, which has an atomic ratio of 5:8:2 (Cu:Cr:Pb), exhibited the highest catalytic activity for the pyrolysis of AP when the pyrolytic temperature of AP decreased from 441.3 °C to 360.2 °C and the Gibbs free energy ( Δ G ≠ ) decreased from 199.8 kJ·mol −1 to 175.2 kJ·mol −1 , as compared to CuO–Cr 2 O 3 –PbO nanocomposites with other atomic ratios.
研究领域:
材料科学
·
催化化学
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DOI
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Guihong Han,Zhixiao Wang,Bingbing Liu,Yanfang Huang,Shengpeng Su
Existing refractory-life-extending technologies had concentrated on the preparation of homogeneous high-performance refractory materials in advance. In this paper, an in situ anti-erosion approach of conventional corundum-mullite refractory material was proposed for the incineration of hazardous spent high-salt organic liquor, in which the powdery additives were directly added into the spent liquor. The phase transformation, interfacial morphology evolution, and pore distribution of the corundum-mullite refractory with and without Cr 2 O 3 /ZrO 2 addition were compared, and the in situ anti-erosion mechanism was determined via the XRD , SEM, XPS , mercury intrusion porosimetry , and thermodynamic analyses. In conventional corrosion, molten Na 2 SO 4 , the primary phase of incinerating slag, directly entered the interior of the corundum-mullite refractory through pores on the interface. The Na 2 SO 4 strongly reacted with alumina and silica at 1000–1300 °C to produce liquid albite and nepheline. Upon the addition of Cr 2 O 3 into the spent liquor, the Cr 2 O 3 powder was suspended in the spent liquor and deposited at the refractory interface to form a protective (Al,Cr) 2 O 3 solid solution layer with Al 2 O 3 . The dense corrosion-resistant layer of (Al,Cr) 2 O 3 with a depth of 0–3 mm on the surface of the firebricks seldom reacted with molten Na 2 SO 4 . This protective layer can effectively slow down the penetration and erosion of incinerating slag. The environmental risks of Cr(VI) contamination associated with the Cr 2 O 3 addition in the incineration process were also evaluated in this work. Eventually, preliminary trial operation results showed that the service life of the corundum-mullite firebrick was prolonged after 5% Cr 2 O 3 addition into the spent liquor.
研究领域:
材料科学
·
腐蚀与防护
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产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2024
·
IF 5.2
Sen Wang,Hong Chen,Qing Lin,Qian Lu,Wei Lv,Can Wang,Linhao Yu,Yingying Li,Yongdan Li
Two significant strategies for enhancing photocatalyst performance are heterojunction construction and band gap modulation, but up until now, these methods have typically been treated separately. This work examines a strategy combining the heterojunction with a mid-gap state to prepare a novel Cr 2 O 3 modified Cr-doped g-C 3 N 4 photocatalyst for antibiotics degradation. According to the characterization results, the integration of Cr 3d orbital energy level into the original band gap of g-C3N4 results in the formation of Cr-doped g-C 3 N 4 , leading to a reduction in the band gap from 2.80 eV to 2.36 eV. Besides, the constructed Z-type heterojunction enhances the separation of photoinduced carriers. The degradation experiments of tetracycline proved the significant enhancement in the photocatalytic performance of the prepared catalyst. In addition, the degradation effect of the prepared catalyst on tetracycline in micro-polluted lake water was also investigated, revealing the applicability of the catalyst in the purification of natural water environments.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 9
·1-12
·
IF 2.184
Han Wenfeng,Li Xiaojuan,Tang Haodong,Wang Zhikun,Xi Miao,Li Ying,Liu Huazhang
Abstract A Cr 2 O 3 hexagonal prism structure synthesized via the reaction of aqueous CrCl 3 solution with NaBH 4 solution at room temperature followed by calcination of the precipitate in N 2 atmosphere at 500 °C is investigated as an efficient catalyst for dehydrofluorination of 1,1-difluoroethane producing vinyl fluoride. With the assistance of scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy, experimental results revealed that the uniform hexagonal prism has a prism length of 285 ± 43 nm and width of 233 ± 33 nm. It is in the form of loose and net-like aggregation of nano-Cr 2 O 3 with diameter less than 3–5 nm with polycrystalline structure. NH 3 temperature programmed desorption and chlorodifluoromethane dismutation experiments confirm the existence of relatively abundant and strong acidic sites. As a catalyst for dehydrofluorination of 1,1-difluoroethane, compared with commercial Cr 2 O 3 , much higher activity and stability were observed due to the evolution of CrO
x
F
y
species and much higher surface area and mesoporous structure. No significant morphology changes or sintering of the catalyst are observed after 70-h reaction. Compared with the commercial Cr 2 O 3 , we suggest that the much smaller size of Cr 2 O 3 crystalline which possesses higher surface energy, lower strength, and more abundant Lewis acidity and the formation of CrO
x
F
y
during reaction over hexagonal prism catalyst probably contributes to the activity and stability difference between these two catalysts. Graphical Abstract
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Advances
·
2021
·Vol. 3
·期 21
·6048-6055
·
IF 4.553
Dongjin Xie,Qiuyi Luo,Shen Zhou,Mei Zu,Haifeng Cheng
Inkjet printing of functional materials has shown a wide range of applications in advertising, OLED display, printed electronics and other specialized utilities that require high-precision, mask-free, direct-writing deposition techniques. Nevertheless, the sedimentation risk of the refractory functional materials dispensed in inks hinders their further implementation. Herein, we present a bottom-up ink preparation strategy based on Cr2O3 by a one-step solvothermal method. The obtained ink remained stable under an equivalent natural sediment test for 2.5 years. The chemical composition of the solvothermal product was characterized, and the mechanism of the superior dispersion stability of Cr2O3 particles was analysed. These amorphous Cr2O3 particles were capped by ligands generated via low-temperature solvothermal reactions. Ethanol and acetylacetone covering the particle surfaces play an essential role in enhancing the solubility of Cr2O3 particles in the solvent forming the ultrastable colloidal ink. Moreover, this ink was successfully printed using a direct-write inkjet system JetLab®II on nylon fabrics, and the printed area of the fabrics shows a spectral correlation coefficient of 0.9043 to green leaves. Finally, we believe that the one-step bottom-up fabrication method of Cr2O3-based pigment inks may provide a general approach for preparing metal oxide-based pigment inks with long-term dispersion stability.
研究领域:
材料科学
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化学工程
·
喷墨技术
·
功能材料
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Shengjie Xia,Lianyang Zhang,Xiaobo Zhou,Mengmeng Shao,Guoxiang Pan,Zheming Ni
In this paper, Ti-contained Schiff base complex was intercalated into the interlayer of the ZnCr layered double hydroxides (LDHs) to form a novel layered organic–inorganic nanoscale material. And then, the hybrid material was further calcined to make metal oxides composite contained Zn, Cr and Ti (Ti/ZnO–Cr 2 O 3 ). This composite was used to study the performance and mechanism for naphthalene ( l -acid) photodegradation under visible light. The characterization results showed that Ti/ZnO–Cr 2 O 3 composite has higher specific area, more uniform pores size distribution and narrower band gap than that of original ZnCr–LDHs. Both physico-chemical property and photocatalytic performance for l -acid degradation by Ti/ZnO–Cr 2 O 3 were greatly improved with the increasing of calcination temperature, due to the highly crystalline structures with appearance of spinel ingredients of Zn, Cr and Ti. In addition, the molar ratio of Ti/Cr would also influence the photocatalytic property of the materials. Ti/ZnO–Cr 2 O 3 composite with Ti/Cr = 1 and calcined at 800 °C not only has narrow bang gap (2.11 eV) and high surface area (227 m 2 ), but also shows highest photocatalytic performance for l -acid degradation (90.2% within 240 min). Furthermore, the types and amounts of active radicals of photo oxidation reaction were also tested. The photocatalytic mechanism of the Ti/ZnO–Cr 2 O 3 composite was also discussed. Moreover, based on the results from HPLC–MS, GC–MS, FT–IT and DFT analysis, the decomposition intermediates and reaction pathway for l -acid were investigated in detail.
研究领域:
材料科学
·
环境化学
·
光催化
·
纳米材料
·
物理化学
·
环境工程
·
能源与可持续发展
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zixian Wang,Yajun Li,Kai Yang,Yufan Gu,Mingxuan Gu,Limei Pan,Jian Gu,Jian Yang
In this work, high-continuity nano-Cr 2 O 3 films were fabricated on the Al 2 O 3 ceramic substrate surface via the evaporation-induced self-assembly (EIA) method, aiming at decreasing the secondary electron emission yield (SEEY) and increasing the vacuum withstand voltage performance of Al 2 O 3 ceramic for application in electric vacuum devices. The effects of ethylene glycol monomethyl ether (MOE) addition and calcination temperature on the composition, structure, and various properties of the nano-Cr 2 O 3 films were investigated, and the related mechanisms were discussed. Employing MOE and increasing its addition significantly mitigated internal stress during the liquid film formation and crack-free nano-Cr 2 O 3 films were achieved at 15% addition. With the calcination temperature increasing from 300 °C to 1000 °C, the crystallinity, uniformity, and compactness of the film were improved, while the defect states decreased, resulting in an increase in bandgap, surface resistivity, and decrease in SEEY, presenting the particularity of Cr 2 O 3 . When calcined at above 1000 °C, the Cr 2 O 3 film gradually dissolved into the Al 2 O 3 substrate, which led to the increase in bandgap, surface resistivity and SEEY, approaching the intrinsic characteristics of Al 2 O 3 at 1500 °C. The nano-Cr 2 O 3 film calcined at 1000 °C exhibits optimized comprehensive structure characteristics, moderate surface resistivity (1.30×10 16 Ω/□), the lowest SEEY (2.27), and presenting a much improved and impressive vacuum flashover voltage strength of 65 kV/cm.
研究领域:
材料科学
·
纳米技术
·
应用物理学
·
表面工程
·
真空电子学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Yun Guo,Hong-Yi Li,Shuo Shen,Jie Cheng,Jiang Diao,Bing Xie
Chromium sludge is a hazardous solid waste which cannot be effectively treated but only piled up and abandoned, causing serious environment pollution and resource wasting. This work proposes an effective novel process to separately recover all resources in chromium sludge via a sustainable way. The obtained acid solving liquid from chromium sludge is desiliconized by cationic flocculant (PCAM) to induce coprecipitation of polysilicate gel and PCAM , which mixture is calcinated to generate the product of white carbon black in purity of 94.35% with a recovery of 92.58%. After desiliconization, V in the solving liquid is selectively extracted by microemulsion (ME), which is recovered as V 2 O 5 in purity of 99.34% with a recovery of 95.53% by the subsequent procedure of stripping-precipitation-calcination. The Fe 3+ in raffinate is reduced to Fe 2+ cations by Na 2 SO 3 , and is then recovered by H 2 C 2 O 4 precipitation to generate the FeC 2 O 4 product in purity of 99.12% with a recovery of 98.25%. Cr 3+ cations in residual solution are recovered by alkaline precipitation and calcination to generate the Cr 2 O 3 product in purity of 98.25% with a recovery of 92.68%. This work provides fresh penetrations into the synchronous detoxification, resource recovery and value-added utilization of hazardous industrial solid wastes.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
CANADIAN METALLURGICAL QUARTERLY
·
2024
·
IF 1.3
Hong-Rui Yue,Zhi-Hao Huo,Xiang-Xin Xue,Jing Liu
The Boltzmann-Matano method and its derivatives are widely used approaches for calculating interdiffusion coefficients. However, raw practical C-x curves typically have to be modified to fit with various functions due to their fluctuations, failing to reflect their essential characteristics. Herein, we introduce YX-IDCRC and YX-IDCRC software to calculate the interdiffusion coefficient using raw C-x curves. Firstly, we apply YX-IDCRC for the ideal (not fluctuate) and simulated (with noises) data, the calculated average of the ideal data closely matches the reported result. Secondly, we propose a method to determine the FWHM interval and distinguish the abnormal points by examining the calculated. Thirdly, we prepare the Cr2O3-CaO diffusion couples in the Fe2O3 matrix, and the average at 1273, 1298, 1323, and 1348 K are calculated as 3.10×10−9, 4.82×10−9, 7.02×10−9, and 2.4×10−8 cm2·s−1, respectively. Deduction from the Arrhenius equation indicates the diffusion activation energy (ED) as 369.97±51.80 kJ·mol−1, which lies in the reported results and verifies the reliability of YX-IDCRC on the practical diffusion systems. Finally, the supervision of limitation and applicability indicates that YX-IDCRC is applicable for the binary or pseudo-binary systems with S- or half-S-shape C-x curves.
研究领域:
材料科学
·
物理学
✓ 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）