CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Luo Feng,Liqing Li,Meiqi Zhang,Yijie Yang,Xiaoqi Sun
This paper reports the syntheses of a series of polychromatic pigments with the general formula LiAl 1- x M x (MoO 4 ) 2 (M = Fe, Pr, Ho, Nd, Er, Ce; x = 0–0.4) and the characterization of near-infrared reflectance properties. The synthesized pigments exhibited green (Pr), lavender (Nd), pink (Er) and different yellows (Fe, Ho, Ce). The XRD patterns of typical LiAl 1- x Fe x (MoO 4+δ ) 2 samples show that the prepared samples are triclinic lithium aluminum molybdate structures with space group P -1.The iron in the sample mainly existed in the form of Fe 3+ , which led to the directional growth of grains with different morphologies. The near-infrared solar reflectance (R*%) of LiAl 1- x Fe x (MoO 4 ) 2 pigments reached 94.19%. As the doping concentration of rare earth was increased, the color of the pigments gradually deepens. By introducing rare earth elements Pr, Ho, Nd, Er, and Ce into the LiAl(MoO 4 ) 2 matrix, the color of the pigment was successfully changed from white to green, lavender, pink, and yellow, indicating that doping can control the color of the pigment. Moreover, the prepared pigments had high R*% (>87%), indicating that the pigment samples have excellent thermal insulation properties and can be used as a new type of reflective thermal insulation coatings.
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Sustainable Chemistry and Pharmacy
·
2023
·
IF 6
Qiuyun Zhang,Yaping Wu,Xingyue Hong,Zhenying Li,Yanting Lei,Rongfei Yu,Taoli Deng,Yutao Zhang,Peihua Ma
Different ligand functionalized bimetallic organic framework ((Zr/Ce)UiO-66- X ( X = H, NO 2 , NH 2 and (OH) 2 ) solids-supported phosphotungstic acid (HPW) has been fabricated through a facile impregnation process, and used in the esterification of methanol with oleic acid (OA). The obtained composites were characterized by FTIR , XRD, NH 3 -TPD, SEM-EDS, N 2 adsorption-desorption isotherm, TG , Py-FTIR, and XPS. The characterization analysis shows that the HPW/(Zr/Ce)UiO-66-NO 2 composite possesses the proper catalytic features, such as the greatest number of both strong Brønsted and Lewis acid sites, wider pores, relatively high surface area, and the existence of synergistic catalytic effects between HPW and (Zr/Ce)UiO-66-NO 2 framework. In the screening, the maximum OA conversion rate using (Zr/Ce)UiO-66-NO 2 , HPW/(Zr/Ce)UiO-66-NO 2 , HPW/(Zr/Ce)UiO-66, HPW/(Zr/Ce)UiO-66-NH 2 , HPW/(Zr/Ce)UiO-66-(OH) 2 catalysts is 13.7%, 91.6%, 81.6%, 80.7%, and 72.6% at 110 °C for 3 h, respectively. Moreover, the HPW/(Zr/Ce)UiO-66-NO 2 catalyst presents the better reusability over four cycles. Besides these, the HPW/(Zr/Ce)UiO-66-NO 2 catalyzed esterification reaction is estimated to have an activation energy of 33.7 kJ/mol. This present study provides an effective route for realizing biofuel production on an industrial scale involving heteropolyacids/bimetallic MOFs synergistic catalysts.
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OPTICAL MATERIALS
·
2023
·
IF 3.9
Ke Sun,Haibin Lin,Rui Zhang,Jinlong Zhu,Liping Wang,Songbai Han,Xiaofei Wang
The emerging laser-driven phosphor-converted white laser diodes (w-LDs) demand highly efficient and thermally stable color converters. To this end, the Ce 3+ luminescence in the rekindled La–Si–O–N host, and the impacts of NH 4 Cl flux and post-processing are investigated systematically. On the basis of the XRD results, well crystalline Ce 3+ -doped La 5 Si 3 O 12 N and LaSiO 2 N are obtained at 1600 °C for 5 h and 1500 °C for 4 h, respectively. Impressively, the representative La 5 Si 3 O 12 N:0.04Ce 3+ and LaSiO 2 N:0.03Ce 3+ exhibit a broad excitation band from 240 nm to 400 nm, peaking at around 360 nm, which is well matched with emission from near-UV (n-UV) chip. Under excitation by a n-UV laser, the La 5 Si 3 O 12 N:0.04Ce 3+ and LaSiO 2 N:0.03Ce 3+ produce bright blue light in a wide emission band from 360 nm to 550 nm. The CIE chromaticity diagram reveals the tunability of the hue of these phosphors. The quenching temperature is determined to be 396 K and 429 K for La 5 Si 3 O 12 N:0.04Ce 3+ and LaSiO 2 N:0.03Ce 3+ respectively, indicating superior thermal stability. The addition of 3 wt% NH 4 Cl flux much enhances the emission intensity of both La 5 Si 3 O 12 N:0.04Ce 3+ and LaSiO 2 N:0.03Ce 3+ . Furthermore, the post-treatments markedly improve the luminescence properties by increasing the crystallinity , reducing the surface defect , and changing the morphology. Therefore, it is believed that the present work has promising applications in LD lighting and promoting the development of laser display.
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JOURNAL OF POLYMER SCIENCE
·
2023
·Vol. 61
·期 20
·2426-2439
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IF 3.4
Siyu Jiang,Sheng Li,Xuhui Yang,Lubin Liu,Xiaoli Li,Miaojun Xu
Cerium-containing metal organic framework defined as Ce-MOF was prepared and then combined with piperazine pyrophosphate (PAPP) for preparing flame retardant ethylene vinyl acetate (EVA) copolymer composites. The samples of EVA/PAPP/Ce-MOF achieved UL-94 V-0 rating with the limiting oxygen index (LOI) value of 31.3% when 17 wt% PAPP/Ce-MOF with the mass fraction of 97:3 was introduced. Under the same loading amount of PAPP, the EVA/PAPP only obtained UL-94 V-1 rating with the LOI value of 26.9%. Cone calorimeter test confirmed that the total heat release and total smoke production of EVA/PAPP/Ce-MOF significantly reduced from 132.8 MJ m −2 and 11.5 m 2 for EVA/PAPP to 98.8 MJ m −2 and 7.3 m 2 , with a reduction of 25.6% and 36.5%, respectively. Besides, the maximum smoke density decreased from 488.8 and 375.9 for EVA and EVA/PAPP to 177.5 for EVA/PAPP/Ce-MOF. It indicated that the addition of Ce-MOF and PAPP effectively exerted synergistic flame retardant and smoke inhibition effect for EVA. Moreover, the addition of Ce-MOF enhanced the compatibility of PAPP with EVA matrix, and water resistance of EVA/PAPP/Ce-MOF was higher than that of EVA/PAPP. The x-ray photoelectron spectroscopy texts of residual char of EVA composites indicated that the cerium ion complexed with phosphoric acid and polyphosphate generated by the thermal decomposition of PAPP and then more phosphorus elements remained in condensed phase. As a result, the sufficient, crosslinking and dense char layer with excellent intensity was formed, and the heat, combustible gas and smoke were efficiently inhibited. Consequently, the EVA materials were endowed excellent fire safety as well as low heat and smoke release. Graphical
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INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Guangxin Ren,Baocang Liu,Liang Liu,Minghao Hu,Junpeng Zhu,Xuan Xu,Peng Jing,Jinfang Wu,Jun Zhang
Biomass is a sustainable and renewable resource that can be converted into valuable chemicals, reducing the demand for fossil energy. 5-Hydroxymethylfurfural (HMF), as an important biomass platform molecule, can be converted to high-value-added 2,5-furandicarboxylic acid (FDCA) via a green and renewable electrocatalytic oxidation route under mild reaction conditions, but efficient electrocatalysts are still lacking. Herein, we rationally fabricate a novel self-supported electrocatalyst of core–shell-structured copper hydroxide nanowires@cerium-doped nickel hydroxide nanosheets composite nanowires on a copper mesh (CuH_NWs@Ce:NiH_NSs/Cu) for electrocatalytically oxidizing HMF to FDCA. The integrated configuration of composite nanowires with rich interstitial spaces between them facilitates fast mass/electron transfer, improved conductivity, and complete exposure of active sites. The doping of Ce ions in nickel hydroxide nanosheets (NiH_NSs) and the coupling of copper hydroxide nanowires (CuH_NWs) regulate the electronic structure of the Ni active sites and optimize the adsorption strength of the active sites to the reactant, meanwhile promoting the generation of strong oxidation agents of Ni3+ species, thereby resulting in improved electrocatalytic activity. Consequently, the optimal CuH_NWs@Ce:NiH_NSs/Cu electrocatalyst is able to achieve a HMF conversion of 98.5% with a FDCA yield of 97.9% and a Faradaic efficiency of 98.0% at a low constant potential of 1.45 V versus reversible hydrogen electrode. Meanwhile, no activity attenuation can be found after 15 successive cycling tests. Such electrocatalytic performance suppresses most of the reported Cu-based and Ni-based electrocatalysts. This work highlights the importance of structure and doping engineering strategies for the rational fabrication of high-performance electrocatalysts for biomass upgrading.
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MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Yajun Zhang,Xiaoliang Zeng,Xiaofang Jiang,Hanjiao Chen,Zhou Long
The cerium (Ce)-based UiO-66 metal-organic frameworks were employed for the first time as an effective catalyst for both oxidation and reduction. On one hand, selenium (Se)(VI) was efficiently photo-reduced to volatile species derived from the low lying of Ce 4f orbital and efficient generation of photo-electrons through the frameworks of UiO-66(Ce); on the other hand, the chromogenic substrate, 3, 3′, 5, 5′-tetramethylbenzydine (TMB), was oxidized based on the oxidase-like behavior of UiO-66(Ce) derived from the Ce 4+ /Ce 3+ spontaneous redox couple. The photo-reduced Se(VI) was determined by atomic fluorescence spectrometry , with a linear range of 5.0–200.0 μg/L − 1 , correlation coefficient of 0.998, and detection limit of 1.5 ng/mL − 1 obtained. The colorimetric sensing of mercury (Hg)(II) was accomplished based on the inhibition of TMB oxidation via Hg (II)-TMB interaction, with two linear ranges of 0.1–2.0 μM and 2.25–4.1 μM obtained, and a correlation coefficient of 0.993 and 0.995 obtained, respectively. The catalytic activity of UiO-66(Ce) was demonstrated to be satisfactory for both oxidation and reduction, which further explored the application of UiO-66(Ce) in the field of catalysis.
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Molecular Catalysis
·
2018
·
IF 0
Gui Liu,Lei Sun,Wei Luo,Yue Yang,Junhua Liu,Fang Wang,Curtis J. Guild
Aerobic Baeyer-Villiger oxidation of ketones into corresponding esters were performed over mesoporous Mn-Ce and Mn-Co composite oxides prepared by co-impregnation method and benzaldehyde was used as the sacrificing agent. It was found that the best conversion and selectivity were obtained when the Mn/Ce mole ratio was 1:2 (denoted as Mn 0.33 Ce 0.67 O s ) through investigating the effect of Mn/Ce mole ratio on the catalytic activity. Interestingly, Mn 0.33 Co 0.67 O s (Mn/Co mole ratio was 1:2) catalyst had no catalytic activity for this reaction. X-ray diffraction (XRD) results showed that MnO x was completely dissolved into the CeO 2 lattice, and Mn 0.33 Co 0.67 O s sample was existed in the form of spinel structure (Co, Mn) (Mn, Co) 2 O 4 and obvious peaks of Co 3 O 4 . Nitrogen adsorption-desorption measurements revealed that Mn 0.67 Ce 0.33 O s , Mn 0.5 Ce 0.5 O s , Mn 0.33 Ce 0.67 O s and Mn 0.33 Co 0.67 O s materials possessed mesoporous structure. X-ray photoelectron spectroscopy (XPS) analysis showed that the highest concentration of Ce 3+ on the surface of Mn 0.33 Ce 0.67 O s catalyst, which could create unsaturated chemical bonds, charge imbalance, and oxygen vacancies on the surface of samples, it is beneficial to the oxidation reaction. Additionally, XPS data revealed that Mn 0.33 Ce 0.67 O s catalyst has great potential in catalytic oxidation due to the large amount of active oxygen species on the surface. In addition, manganese and cobalt species on the surface of Mn 0.33 Co 0.67 O s are almost present in the form of Mn 2+ and Co 3+ , it is known that Mn 2+ can serve as a potent antioxidant and scavenge the activity of active oxygen species, while Co 3+ ions can prevent the formation of oxygen vacancies and inhibit the release of reactive oxygen species, thus the presence of Mn 2+ and Co 3+ inhibited the catalytic activity of Mn 0.33 Co 0.67 O s catalyst. The diffuse reflectance ultraviolet-visible spectroscopy (DR-UV-vis) and hydrogen temperature-programmed reduction (H 2 -TPR) results are in accordance XPS data.
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TALANTA
·
2018
·
IF 4.244
Sobia Niazi,Xiaole Wang,Imran Pasha,Imran Mahmood Khan,Sen Zhao,Muhammad Shoaib,Shijia Wu,Zhouping Wang
Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by fungi on stored grains. The earlier detection methods used for ZEN rely on expensive equipment, time-consuming sample preparation and temperature sensitive antibodies. The current work, proposed a novel strategy based on ZEN aptamer labeled with amine-functionalized magnetic nanoparticle (MNPs) as a capture probe and time-resolved fluorescence (TRFL) nanoparticles labeled with complementary DNA (cDNA) as a signal probe. Under the optimized conditions, TRFL intensity at 544 nm was used to measure ZEN (R 2 = 0.9920) in the range of 0.001–10 ng mL −1 and limits of detection (LOD) for proposed method was 0.21 pg mL −1 . The specificity of bioassay was also determined by using other mycotoxins (OTA, AFB 2 , DON and Patulin) and results showed that the aptamer are specific to recognize only ZEN. The analytical applications of the present bioassay in maize and wheat samples were also examined and results were compared with existing methods. Based on these findings, it is suggested to use current rapid and simple bioassay for the determination of ZEN in food and agricultural products.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Chao Zhu,Futao Li,Shaowen Ji,Zhengyan Li,Xiangping Chen
Recycling valuable metals from spent nickel-metal hydride (NiMH) batteries has significant environmental and economic benefits. This study aimed to separate and recover nickel (Ni), cobalt (Co), cerium (Ce), lanthanum (La), and neodymium (Nd) from waste NiMH batteries using ion-exchange fibers as the adsorbent material in an adsorption chromatography process. Static adsorption experiments showed the metal adsorption processes followed the Langmuir model, indicating mono layer coverage, and quasi-second order kinetics, suggesting chemisorption. In the chromatographic separation study, optimal conditions of pH 2, 1/10 diluted feed solution, fully packed column, 3 mL/min flow rate, and 0.2 mol/L acid elution enabled effective separation of the five metals. According to distribution coefficients, the metals were preferentially adsorbed in the order: Nd 3+ > La 3+ > Ce 3+ > Co 2+ > Ni 2+ . Transition metals Ni 2+ and Co 2+ were first separated from rare earths Ce 3+ , La 3+ and Nd 3+ . Subsequently, good separation among the rare earth elements was achieved. After ten adsorption-desorption cycles, the fibers maintained excellent stability with only 9.2 % capacity loss. The results demonstrate the adsorption chromatography method can efficiently recover mixed metals from waste NiMH batteries individually for full value utilization.
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ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Zihao Li,Zewen Chen,Chen Ye,Lixi Gong,Hui Wang,Jie Zhou
Despite the low cost of supported non-precious metal catalysts, their catalytic activity is significantly lower than that of precious metal catalysts in the catalytic oxidation reaction of volatile organic compounds (VOCs). In order to enhance the catalytic activity of supported non-precious metal catalysts, we introduced an ultra-low loading of palladium into the existing catalytic system and employed a plasma preparation process instead of the conventional impregnation method. The approach significantly improves the catalytic activity of the active sites on the catalyst. The results indicate that, compared to the supported Pd and CuMnCeO x catalysts prepared by conventional impregnation method, the Pd/CuMnCeO x /SiO 2 -P catalysts prepared via plasma exhibit a higher proportion of lattice defects (oxygen vacancies). Furthermore, the doping of the ultra-low Pd could facilitate the formation of additional lattice defects in the composite oxide. As a result, it can improve the content of surface active oxygen and enhance the adsorptive strength of hexane on the surface of the catalyst. The Pd/CuMnCeO x /SiO 2 -P catalysts exhibit high catalytic activity and stability in the catalytic oxidation of n-hexane. This work promotes the potential application in the preparation of catalyst with ultra-low precious metal loading.
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Surfaces and Interfaces
·
2024
·
IF 5.7
Chengzhi Wang,Zhenbang Tian,Weiqing Huang,Jingyuan Hu,Xing Xing
Owing to the different reaction properties and deactivation mechanisms caused by the structural discrepancy of monolithic catalysts, abundant scientific results of powder or granular NH 3 -SCR catalysts have still not sufficiently robustly applied in recent years. Furthermore, minimal research has been focused on monolithic catalysts. As a result, this work prepared monolithic Mn-Fe-Ce/Al 2 O 3 catalysts by active component impregnation (ACI-Mn-Fe-Ce/Al 2 O 3 ) and precursor impregnation methods (PI-Mn-Fe-Ce/Al 2 O 3 ) and investigates the long-term SO 2 and H 2 O resistance of the catalysts. Compared with the PI-Mn-Fe-Ce/Al 2 O 3 catalyst, the monolithic ACI-Mn-Fe-Ce/Al 2 O 3 catalyst showed better performance. The catalytic activity follows a bell-shaped curve with an optimal performance at a drug loading of 5 %. The ACI-Mn-Fe-Ce/Al 2 O 3 catalyst exhibits long-term resistance to SO 2 and H 2 O and can still convert more than 70 % NO x after 168 h of SO 2 and H 2 O resistance test. Characterization of the ACI-Mn-Fe-Ce/Al 2 O 3 catalysts before and after the reaction showed that the reducibility decreased after the reaction, and more Mn 4+ was transformed into Mn 2+ to weaken the catalytic activity. However, more Fe 2+ and Ce 3+ were generated during the reaction, increasing the number of oxygen vacancies, oxygen defects, and hydroxyl-like groups, all of which would contribute to a certain extent to counteract the passivation effect of SO 2 on the catalysts. In situ DRIFTs analysis shows that the formation of surface sulfates has a minimal effect on the adsorption of NO, but it does affect the adsorption of coordinated NH 3 on Lewis acid sites. This work elucidates the deactivation details of Mn-Fe-Ce/Al 2 O 3 catalysts from the perspective of physicochemical properties, which provides a reference for the development of better low-temperature SO 2 -resistance catalysts for industrial applications.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 7
·1453-1465
·
IF 3.286
Niazi Sobia,Khan Imran Mahmood,Yan Lv,Khan Muhammad Issa,Mohsin Ali,Duan Nuo,Wu Shijia,Wang Zhouping
A rapid and highly sensitive time-resolved fluorescence (TRF)-based aptasensor for simultaneous recognition of mycotoxins ochratoxin A (OTA) and fumonisin B 1 (FB 1 ) was developed using multi-color, Ln 3+ -doped time-resolved fluorescence nanoparticles (TRF-NPs) (NaYF 4 : Ce, Tb and NH 2 -Eu/DPA@SiO 2 NPs) coupled with complementary strand DNA (cDNA) as luminescence probe and aptamers-conjugated amine-functionalized Fe 3 O 4 magnetic nanoparticles (MNPs) act as a capture probe. Under the optimized conditions, the time-resolved fluorescence intensities at 544 and 618 nm corresponded with Tb 3+ and Eu 3+ , respectively, were used to measure FB 1 ( Y = 19,177.1 + (− 12,054.4) x , R 2 = 0.9917) and OTA ( Y = 4138.8 + (− 11,182.6) x , R 2 = 0.9924), respectively. The limits of detection (LODs) for FB 1 and OTA were 0.019 pg mL −1 and 0.015 pg mL −1 , respectively, which were much lower than previously described methods for simultaneous recognition of mycotoxins OTA and FB 1 while detection range varied from 0.0001–0.5 ng mL −1 . This aptasensor was effectively applied to quantity FB 1 and OTA in maize samples and results were compared with ELISA method. This is the first reported time-resolved fluorescence (TRF)-based aptasensor to detect two agriculturally important toxins in the maize. The developed aptasensor has potential to be used for detection of toxins in food safety fields.
Graphical abstract
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高影响因子
危险品化学品经营许可证（带存储）