CHEMISTRY OF MATERIALS
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2022
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IF 10.508
Yan Liu,Ruoxuan Guo,Kaiping Yuan,Min Gu,Mengli Lei,Chenyi Yuan,Meiqi Gao,Yuejie Ai,Yaozu Liao,Xuanyu Yang,Yuan Ren,Yidong Zou,Yonghui Deng
Chemiresistive gas sensors are widely used in environmental monitoring and industry production; however, their selectivity and sensitivity are yet to be improved and their working temperature is usually too high (around 250 °C), which limit their applications in detecting trace gases at low temperatures due to the low activity of sensitive layers. Herein, novel Ce-doped mesoporous WO3 with high specific surface areas of 59–72 m2/g, a stable crystalline framework, and finely tailored pore walls was synthesized via a facile in situ cooperative assembly method combined with a carbon-supported crystallization strategy. The doping of Ce atoms in the mesoporous WO3 pore wall can effectively adjust the coordination environment of W atoms, giving rise to dramatically enhanced oxygen vacancy (Ov) and forming Wδ+-Ov sites. As a result, the obtained Ce-doped mesoporous WO3 showed excellent H2S sensing performance at a low working temperature (150 °C) with an ultrahigh response value (381 vs 50 ppm), fast response dynamics (6 s), outstanding selectivity, and antihumidity property as well as good long-term stability. The superior gas sensing performance is attributed to the increased Ov density and enhanced conversion of surface-adsorbed H2S into SOx and SOx2– during the surface adsorption-catalysis reaction in the sensitive layer. Density functional theory (DFT) calculations reveal that Ce4+ is embedded into the crystal lattice of WO3 to form an optimal structure rather than atom substitution, and Ce-doped WO3 shows a higher H2S adsorption energy and a larger charge transfer than that in pure WO3, accounting for the better H2S sensing response of Ce4+-doped WO3. Furthermore, a novel gas sensing module and smart portable sensor device based on Ce-doped mesoporous WO3 was developed for efficient real-time monitoring of H2S concentration on a smartphone via Bluetooth communication.
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ENERGY
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2022
·
IF 8.857
Haifeng Jiang,Haipeng Liu,Jiaxin Dong,Jiaxing Song,Sunhua Deng,Jie Chen,Yu Zhang,Wenpeng Hong
Using cellulose to produce high-quality oxygenated fuels or chemicals is becoming an important way to replace chemical synthesis technology. In this work, the Ce–Co–Na ternary composite metal catalyst is synthesized and used for catalytic cracking of cellulose to prepare the ketone-rich bio-oil production. To construct an environment-friendly process, CO 2 is used as a pyrolysis reaction atmosphere to improve the enrichment of ketones. Strong synergistic effects among metal components effectively promote the thermal-cracking of cellulose to produce primary products (anhydrosugars), and further convert to oxygenates due to the excellent oxygen transferability of the catalyst. The introduction of CO 2 enhances the selectivity of ketones in the liquid product, especially 2,3-dimethyl-2-cyclopenten-1-one. The highest content of ketones in the liquid is 22.73%, which is about four times higher than that of the blank sample. In addition, the generation of CO in the syngas is promoted. This study provides an alternative way for the pyrolysis of biomass to prepare ketone platform compounds and syngas production .
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ELECTROCHIMICA ACTA
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2022
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IF 7.336
Yongxiang Wang,Guocan Shen,Ting Tang,Jinming Zeng,Rizwan Ur Rehman Sagar,Xiaopeng Qi,Tongxiang Liang
Electrochromic capacitors are attracting a huge attention due to their dual functions in energy-saving and energy storage. Electrochromic and energy storage performance of the films could be effectively improved through regulating their physical phase and morphology. In the present work, the physical phase and morphology of the WO 3 nanofilms were regulated by doping RE ions (RE = Ce, Eu, Sm, Gd) using one-step hydrothermal technology. The three-dimensional (3D) urchin-like crystal WO 3 nanofilm would transfer into the 3D nest-like WO 3 (WO 3 -RE) nanofilms that consisted of crystal and amorphous phase by doping RE ions. Compared with the pure WO 3 nanofilm, the WO 3 -RE nanofilms exhibited higher optical contrast, faster switching speed, longer cyclic stability, and larger areal capacitance owing to faster ions transfer rate and more stable film structure. The optical contrast of WO 3 -Eu and WO 3 -Sm nanofilms were 76.3% and 73.8% at 633 nm, 75.5% and 74.6% at 900 nm wavelength, respectively. Notably, the WO 3 -Eu and WO 3 -Sm nanofilms could retain 99.6% and 99.1% of their original optical contrasts after 1000 cycles, respectively. Additionally, the areal capacitance of ECDs based on the WO 3 /PB, WO 3 -Ce/PB, WO 3 -Eu/PB, WO 3 -Sm/PB, and WO 3 -Gd/PB were 26.15, 49.27, 58.23, 71.46, and 79.52 mF/cm 2 at 0.3 mA/cm 2 , respectively. ECDs based on the WO 3 -RE/PB are promising for energy-saving and energy storage dual functional smart windows.
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Royal Society Open Science
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2022
·Vol. 9
·期 8
·
IF 3.653
Lin Li,Ting Yu,Zhenghua Qian,Xiaoling Wu,Hui He,Guoan Ye,Yanbo Qiao
Two new metal-organic frameworks (MOFs) (Th/ Ce -TCPE) based on 1,2,4,5-tetrakis(4-carboxyphenyl)ethylene were obtained using a straightforward reaction under moderate conditions. Th and Ce formed the central units of this MOF in the mononuclear and in the unusual trinuclear cluster configurations, respectively. The resulting MOFs were analysed by fluorescence spectroscopy to understand their luminescence. The obtained data revealed that benzene's electron cloud density and torsion angle on the ligand were affected by the acetic acid molecule and Th(IV), which caused Th-TCPE to irradiate stronger blue emission, but Ce-TCPE showed no fluorescence due to the self-quenching. Such a unique luminescence property could be used for fluorescence or radiopharmaceutical sensing.
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PubMed
高影响因子
Catalysts
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2022
·Vol. 12
·期 7
·775
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IF 4.501
Yang Liu,Gongda Chen,Jianjun Chen,Hejingying Niu
Metal organic framework (MOF) is a type of porous organic material. In this work, three catalysts loaded with noble metal Pt were prepared by NaBH4reduction method with three different morphologies of Ce–MOF as carriers. Their physicochemical properties were characterized by XRD, Raman, FTIR, N2adsorption, SEM, XPS, and TGA. The catalytic performances of different catalysts were evaluated via toluene oxidation and CO2selectivity. Rod–shaped Pt/MOF–BTC exhibited best catalytic performance compared to Pt/MOF–808 and Pt/UiO–66, its T50and T90were 140 °C and 149 °C, respectively. After deducting the effect of specific surface, Pt/MOF–BTC still had the lowest apparent activation energy (62.8 kJ·mol−1), which is due to the abundant atomic Pt and oxygen vacancy content on its surface. After the reaction, the structure of Pt/MOF–BTC may become amorphous according to XRD results. Furthermore, the presence of amorphous structure had no effect on the catalytic activity of the catalyst. In the stability test of Pt/MOF–BTC to toluene oxidation, both toluene conversion and CO2selectivity remained at 100%, and remained stable for 11 h. Moreover, Pt/MOF–BTC also had better resistance to high weight hourly space velocity (WHSV) or water resistance. The catalyst maintained high catalytic activity for 3 times reusability. This study provides valuable experience for the future work of MOF in the field of VOC catalytic oxidation.Keywords:Ce–MOF;noble metal;oxygen vacancy;catalytic oxidation
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JOURNAL OF RARE EARTHS
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2022
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IF 4.632
Luyao Zhang,Fuli Tian,Huan Li,Jiangman Meng,Qi Liu,Xiaoqian Guo,Yun Qiu,Jun Zhang,Changyan Li
A series of non-enzymatic graphene functionalized biosensors was developed via deposition precipitation method for lactic acid (LA) detection, which were characterized by transmission electron microscopy (TEM), Raman spectroscopy , X-ray photoelectron spectroscopy (XPS), gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, and proton nuclear magnetic resonance ( 1 H NMR). The electrochemical performances of the non-enzymatic biosensors were measured by means of the electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) method. The comprehensive analysis of structures shows that Pt, CeO 2 , and GO components interact with each other. During the storing and releasing oxygen, the valence ratio of Ce 3+ /Ce 4+ and the number of oxygen vacancies in CeO 2 change accordingly, which can be conducive to increasing electronic transmission capacity and finally leads to the improvement of electrocatalytic performance. Among them, the Pt/CeO 2 /GO biosensor containing 0.47 at% platinum exhibits an excellent electrochemical detection performance with high sensitivity of 12.3 µA·L/ (mmol·cm 2 ) and a low limit of detection (LOD) of 5.12 μmol/L in a wide linear range from 10 to 900 μmol/L. In addition, the proposed biosensor possesses a promising anti-interference capability, as well as high stability and good reproducibility, which was assessed by testing the cyclic voltammogram in 0.1 mol/L lactic acid one year later. The underlying mechanism was proposed for electrochemical oxidation of LA to carbon dioxide and acetic acid with the synergistic effect among Pt, CeO 2 , and GO. Furthermore, the results of the standard addition method in real samples (human serum and urine samples) reveal that the lactic acid detection of the non-enzymatic Pt/CeO 2 /GO biosensor is accompanied by high reliability. Thus, it will be a valuable biosensor for in vitro detection of lactic acid level in clinical samples.
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CERAMICS INTERNATIONAL
·
2021
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IF 4.527
Xinyu Zeng,Yang Li,Jia Dong,Jingli Li,Zhaoyu Yang,Chunlin Song,Gang Liu,Yan Yan
In the current study, a series of CeO 2 -doped ( x = 0.01, 0.015, 0.02, 0.025 mol) ceramic samples were prepared, and the valence of Ce in the perovskite was analyzed in detail, revealing the polarization contribution and effect mechanism of the doped Ce element in the 0.65BaTiO 3 –0.35Sr 0.7 Bi 0.2 TiO 3 ceramic. The phase structure and electrical stored energy performance of the resulting ceramics were also characterized. It was found that adding an appropriate amount of CeO 2 to BaTiO 3 was helpful for improving the relaxor behavior, promoting electric storage, and releasing ceramic materials. Particularly, the electric breakdown strength of the 0.02Ce-doped specimen reached 330 kV/cm, and the corresponding density and efficiency were 2.57 J/cm 3 and 81.30%, respectively. In addition, doping with Ce caused the ceramics to exhibit good stability at frequencies of 1–300 Hz and over a temperature range of 30–150 °C. A high current density ( C D ) and power density ( P D ) were obtained in charge–discharge tests.
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APPLIED SURFACE SCIENCE
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2021
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IF 6.707
Girma Sisay,Hairus Abdullah,Dong-Hau Kuo,Worku Lakew,Hardy Shuwanto,Sleshi Fentie
The works on photocatalytic hydrogen production and green chemical conversion have received significant attention due to the current need for clean energy and a secure environment. Herein, Ce and Ga codoped Zn(O,S) has been synthesized with different amounts of Ce using facile precipitation method at a low temperature of 95 °C and characterized by XRD, SEM, HRTEM, XPS, EPR, Raman, DRS, PL, EIS, UV–vis, GC–MS, and photocurrent response measurements. The as-prepared photocatalysts were utilized for hydrogen production and hydrogenation of toxic organic compounds, viz. nitrobenzene (NB) and azobenzene (AB) into a valuable product of aniline. The incorporation of Ce and Ga into Zn(O,S) enhanced the hydrogen evolution and hydrogenation reactions of NB and AB. This notable enhancement was ascribed to the synergistic effects of Ce and Ga dopants to form positively charged defects that trap the photogenerated electron. The trapping mechanism improves the photogenerated charge separation and transfer as confirmed with impedance spectroscopy (EIS), transient photocurrent response, and PL measurements. The highest hydrogen production was attained by 15Ce-5Ga-Zn(O,S) with a rate of 7130 μmol∙g − 1 ∙h − 1 in 10% ethanol solution. In addition, NB and AB were effectively converted to aniline in 15 min and 30 min, respectively. A plausible photocatalytic hydrogenation mechanism for both hydrogenation of NB and AB is proposed with the steps of surface adsorption, molecular diffusion, pinning at oxygen vacancy sites, and hydrogenation reaction with the help of in situ generated H + coupled with electrons.
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ANALYTICA CHIMICA ACTA
·
2020
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IF 5.977
Yan Liu,Lianying Zhang,Qinge Li,Han Dai,Ting Xiang,Gangyi Yang,Ling Li
In this work, a colorimetric assay for visfatin detection is described. The mixed valence state Ce-MOF (MVCM) modified by platinum nanoparticles (Pt NPs) is used as a novel catalyst. MVCM exhibits excellent intrinsic peroxidase-like catalytic activity due to the spontaneous recycling of the Ce(III)/Ce(IV) system. Pt NPs serve not only as a carrier of the –NH 2 -modified single strand DNA (S1) but also as a synergistic catalyst of MVCM. The capture probe (S2) attached to the streptavidin-modified magnetic beads (Mag-SA) could combine with the aptamer to form the Mag-SA/S2/aptamer complex. When in the presence of the target visfatin, aptamer specifically combines with the visfatin, which induces the release of Mag-SA/S2 from the Mag-SA/S2/aptamer complex. At this time, the [email protected] /S1 complex connects with the released Mag-SA/S2, which quickly catalyzes the 3,3,3′,3′-tetramethylbenzidine (TMB), leading to a color change. Under optimal conditions, the absorbance increases linearly when the concentration ranges from 1 ng mL −1 to 100 ng mL −1 , and the detection limit is as low as 0.11 ng mL −1 . Furthermore, Mag-SA/S2 can be reused at least five times by using the uracil-DNA glycosylase (UDG) and an external magnetic field. The proposed method shows satisfying reproducibility, stability, specificity, and sensitivity, and it was successfully applied to detect visfatin in spiked human serum samples. Thus, it has great potential for clinical research, detection, and catalytic applications.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
JiaYu Chen,Peng Fu,Daofei Lv,Yang Chen,Meiling Fan,Junliang Wu,Amogh Meshram,Bin Mu,Xiang Li,Qibin Xia
A high-performance denitration catalyst based on Mn-Ce mixed-oxide derived from a specific Mn/Ce precursorwas fabricated by solvothermal method. It exhibited outstanding low-temperature activity, which achieved above 90% NO x conversion in the temperature of 150–310 °C. Remarkably, Mn-Ce mixed-oxide demonstrated a much better SO 2 tolerance, in which the NO x conversion increased from 92.6% to 97.8% at 150 °C after introducing 200 ppm SO 2 . The synthesized Mn-Ce mixed-oxide has a porous structure with abundant chemisorbed oxygen spices and exposed active sites. In addition, the increased acidity and redox capacity enhanced the catalytic activity after introducing SO 2 . Meanwhile, the injection of SO 2 separates NH 3 adsorption sites from oxidation agents, inhibiting the unwanted oxidization of ammonia to nitrogen oxides. Furthermore, the reaction pathway on Mn-Ce mixed-oxide proved to be the L-H mechanism based on in situ DRIFTS. Thus, the synthesized Mn-Ce mixed oxide demonstrated an excellent denitration performance and the especially high SO 2 tolerance, showing great potential for low-temperature NH 3 -SCR.
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Catalysts
·
2020
·Vol. 10
·期 11
·1329
·
IF 3.52
Shijie Hao,Yandi Cai,Chuanzhi Sun,Jingfang Sun,Changjin Tang,Lin Dong
Monolithic Mn-Fe-Ce-Al-O catalyst with honeycomb cordierite ceramic as a carrier was reported for the first time for low temperature deNOxapplication. In the reaction of selective catalytic reduction (SCR) of NO with NH3, a NO conversion of above 80% at 100 °C was obtained. Notably, the catalyst also showed excellent resistance against SO2and H2O. About 60% NO conversion was maintained after successive operation in the mixed stream of SO2and H2O for 168 h. The Brunner−Emmet−Teller (BET) measurement, SEM, EDS, thermogravimetric analysis (TG), FT-IR, and XPS results of the used catalysts indicated that certain amounts of ammonium sulfate was formed on the surface of the catalyst. XPS results revealed that partial of Fe2+was oxidized to Fe3+during the reaction process, and Fe2+species have strong redox ability, which can explain the decrease in activity after reaction. In addition, SO2and H2O induced a transformation of Ce from Ce4+to Ce3+on the surface of the catalyst, which increased the amount of chemisorbed oxygen. Owing to these factors, the addition of Ce and Fe species contributes to excellent resistance of the catalyst to SO2and H2O.Keywords:honeycomb catalyst;Mn-Fe-Ce-Al-O;low temperature denitration;water and sulfur resistance
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ACS Catalysis
·
2020
·
IF 12.35
Bangxin Li,Shuai He,Jibiao Li,Xiangling Yue,John T.S. Irvine,Deti Xie,Jiupai Ni,Chengsheng Ni
Employment of identical oxides for the cathode and anode in a symmetrical solid oxide fuel cell (SSOFC) is beneficial for decreasing the fabrication costs of a robust cell. Ce doping on the A site of SrFeO3 increased the structural stability in a reducing atmosphere, but ceria was found to exsolve from the perovskite during the cooling process in the air if the doping level reached 20 atom %. The additional doping of 5 atom % Ru in Sr0.8Ce0.2FeO3 on the Fe site could prevent the ceria segregation in air and induce the surface decomposition under fuel conditions for the formation of nanoscale SrO, CeO2, and Ru0. The SSOFC with Ce/Ru codoped SrFeO3 on a Sr- and Mg-doped LaGaO3 electrolyte showed a small Rp value (0.12 Ω cm2) when H2 and ambient air were used as fuel and oxidant, respectively. The peak power densities of 846 and 310 mW cm–2 were achieved at 800 °C using H2 and C3H8 as fuel, respectively. The excellent coke resistance of the anode could be related to the simultaneous in situ exsolution of CeO2, SrO, and Ru0 nanoparticles.
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