Materials Research Express
·
2021
·Vol. 8
·期 10
·105002
·
IF 1.62
Wenchang Xi,Pan Jian,Xisong Mao,Deyang Ning,Xuewen Xia,Guohua Liu,Dongyang Shi,Yuanpei Lan
In this work, aiming to evaluate and compare the luminescent property of Eu3+ doped La(OH)3 nanorods and its decomposed compounds of LaOOH and La2O3, La(OH)3: Eu3+ nanorods were synthesized and the decomposition behaviors in air and hydrogen were revealed. Then the luminescent property of 0%–8% Eu3+ doped La(OH)3 nanorods and the 300 °C–800 °C calcined La(OH)3: Eu3+- 4% were studied. Results show that LaOOH is intermediate product during the degradation of La(OH)3 in air or H2, which can be formed at a temperature range in 372.3 °C–592.9 °C in air. Intensity of emission spectra of La(OH)3: Eu3+ nanorods increases with the rising of Eu3+ dopant concentration, and the emission property of Eu3+ doped LaOOH and La2O3 is varied and strengthened with that of La(OH)3: Eu3+. Luminescent matrixes of LaOOH and La2O3 show similar emission spectrum and intensity, and the transitions of the D0 → 7F1 and D0 → 7F2 of Eu3+ each bifurcate into two peaks for both europium (III) doped La2O3 and LaOOH. The revealed results suggest that LaOOH is a relative thermal-stable compound and should be an appropriate matrix as similar as La2O3 for luminescent applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2020
·
IF 4.302
Renjun Li,Yanan Zhou,Xueqian Wang,Langlang Wang,Ping Ning,Lei Tao,Jun Cai
La 2 O 3 /Bi 2 O 3 photocatalysts were prepared by impregnation of Bi 2 O 3 with an aqueous solution of lanthanum precursor followed by calcination at different temperatures. The composite materials were used for the first time for the photocatalytic removal of Hg 0 from a simulated flue gas under UV light irradiation. The results showed that the sample containing 6 wt.% La 2 O 3 and calcined at 500°C has the highest dispersion of the active sites, which was promoted by the strong interaction with the support (i.e., the formation of Bi-O-La species). Since they are fully accessible on the surface, the material also exhibits excellent optical properties while the heterojunction formed in La 2 O 3 /Bi 2 O 3 promotes the separation and migration of photoelectron-hole pairs and thus Hg 0 oxidation efficiency is enhanced. The effects of the various factors (e.g., the reaction temperature and composition of the simulated flue gas (i.e., O 2 , NO, H 2 O, and SO 2 )) on the efficiency of the Hg 0 photocatalytic oxidation were investigated. The results demonstrated that O 2 and SO 2 enhanced the efficiency of the reaction while the reaction temperature, NO, and H 2 O had an inhibitory effect.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2018
·
IF 3.849
Jingru Guan,Jinze Li,Zhefei Ye,Dongyao Wu,Chongyang Liu,Huiqin Wang,Changchang Ma,Pengwei Huo,Yongsheng Yan
A series of La 2 O 3 /CeVO 4 @halloysite nanotubes composites were successfully fabricated by the hydrothermal method. The La 2 O 3 /CeVO 4 @halloysite nanotubes composites display outstanding photocatalytic activity for removing tetracycline (TC) solution under visible light irradiation (λ ≥ 420 nm). After irradiation 60 min, an optimized La 2 O 3 /CeVO 4 @halloysite nanotube composite exhibited a high photocatalytic activity (87.1%), which is 3.89 times higher than that of raw CeVO 4 (22.4%). The improvement of ternary composites performance is attributed to the Ce 3+ and Ce 4+ pairs in CeVO 4 . Besides, constructing heterojunctions between La 2 O 3 and CeVO 4 can inhibit the recombination of photoinduced electrons and holes, which is ascribed to the La 3+ as electron trap to enhance the charge transfer. According to the trapper experiments and Electron Spin Resonance (ESR) analysis, the h + and •O 2− are major reactive species during the degradation. In addition, the oxygen vacancies are in the ternary photocatalyssts. The photocatalytic degradation intermediates of the solution were identified by High performance liquid chromatography-Mass spectra (HPLC-MS).
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2023
·
IF 3.6
Dongyang He,Hailang Liu,Zhuangzhi Wu,Dezhi Wang
The low ductility of refractory Mo-based materials limits their further processing and wide applications. To address this challenge, a composite strengthening and toughening strategy was proposed by the simultaneous addition of WC and La 2 O 3 . And a collaborative improvement of strength and ductility is achieved over the as-sintered Mo-WC-La 2 O 3 , exhibiting a total elongation (TE) of 33.63% and an ultimate tensile strength (UTS) of 611.33 MPa, about 50.27% and 24.76% larger than those of pure Mo, respectively. Furthermore, the corresponding microstructural features and tensile fracture behavior were also discussed to explore the improvement mechanism. And it is found that the enhancement should be attributed to the high relative density, grain refinement, generated substructures and secondary phase particle refinement. Moreover, the additional toughening mechanisms of crack deflection, particles pull-out and crack halt can also prevent crack extension, which helps to give full play to the potential ductility of Mo composites. This work provides a new pathway for manufacturing advanced Mo-based products with excellent strength-ductility balance.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Shaojian Jiang,Xi Liu,Hailong Li,Jun Wang,Zequn Yang,Haoyi Peng,Kaimin Shih
Elemental mercury (Hg 0 ) oxidation over a low-temperature La 2 O 3 -TiO 2 (LaTi) catalyst through a fixed-bed reactor system is reported here. Despite the presence of oxygen (O 2 ), Hg 0 was not effectively oxidized by either hydrogen chloride (HCl) or nitrogen oxide (NO). However, Hg 0 oxidation over the LaTi catalyst was greatly improved when both HCl and NO were present in the simulated flue gas. Several methods, including X-ray photoelectron spectroscopy (XPS), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and temperature-programmed decomposition (TPD), were used to study the inherent mechanisms involved in the Hg 0 oxidation by HCl and NO. The results indicated that the combined presence of HCl and NO exhibited great synergy for Hg 0 catalytic oxidation over the LaTi catalyst. The reaction mechanism is proposed as follows: 1) NO was adsorbed and oxidized on the catalyst surface, forming NO 2 ; 2) the reactive NO 2 then oxidized gas phase Hg 0 to mostly HgO, and; 3) HgO reacted with gas phase HCl to produce HgCl 2 , which escaped from the catalyst’s surface. Differing from previously proposed mechanisms, La 2 O 3 was first studied as an active substance in Hg 0 oxidation. These findings are beneficial for those seeking economical and efficient Hg 0 oxidation catalysts for coal-fired power plants.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Jingjing Xie,Wei Jiang,Fei Tang,Ying Gao,Hongyu Li,Jiyang Li,Deyang Zhao,Zhiqiang Lv,Zhenglong Yang,Yanbin Xu
La 2 O 3 doped hollow porous Ni/NiCo 2 O 4 /C microspheres (NCO-La) are prepared by solvothermal method. The doping of porous La 2 O 3 nanoparticles is crucial to reduce the crystalline grain size of NiCo 2 O 4 and the internal resistance of the electrode, which facilitates ionic and electronic transportation efficiency. Hollow porous NCO-La microspheres with carbon networks have good mechanical strength and can effectively suppress volume expansion and aggregation. The combination of high-conductivity carbon and metallic nickel improves electronic conductivity. The nanostructure in the composite microspheres brings abundant active sites, which facilitates rapid redox of metal ions and allows rapid insertion and removal of Li + , consequently effectively improving the specific capacity. Benefiting from the synergy of well-designed nanostructure, the material shows high Li + storage performance and good stability. At 0.2 A g −1 after 250 cycles, the discharge specific capacity of NCO-La0.1 (1596.2 mAh g −1 ) is far better than NiCo 2 O 4 (655.6 mAh g −1 ) without La 2 O 3 doping. Such design concept of nanostructures provides a promising way to develop high-performance anode materials for LIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Yunjie Dong,Zhoufu Wang,Yan Ma,Hao Liu,Chengji Deng,Zhongfeng Xia,Zhenghuang Quan,Xitang Wang,Ling Zhang
The mechanism of the additive La 2 O 3 on the sintering process of MgO-CaO ceramics was investigated by molecular dynamics simulation, and the interfacial reaction and nanoparticles sintering models were established. The simulations demonstrated that MgO and CaO dissolve into La 2 O 3 crystals, creating O 2- vacancies around Mg 2+ and Ca 2+ . These vacancies significantly increase the diffusion rate of ions. Meanwhile, the La 2 O 3 shifts the sintering driving force from reducing internal energy to increasing entropy, thereby enhancing the sintering degree of nanoparticles. However, excessive La 2 O 3 introduction prolongs solid solution reaction times and impedes particle-particle contact, negatively affecting sintering densification. Experimental results show that the density of MgO-CaO ceramics initially increases with the addition of La 2 O 3 , reaching a peak of 3.43 g/cm³ at 0.3 mol%, before decreasing. This result aligns with the model's predictions regarding the effect of La 2 O 3 addition. Moreover, the established models offer reference for selecting sintering aids in composite ceramics production.
研究领域:
材料科学
·
计算模拟
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Haoran Li,Yan Liu,JinJing Yang,Ming Yuan,Anle Sun,Tiesong Lin,Xuejian Liu,Zhengren Huang
A new La 2 O 3 -doped Y 2 O 3 crucible materials was fabricated and evaluated by TiAl alloys melting test. Microstructure and properties of the La 2 O 3 -doped Y 2 O 3 ceramics were systemically investigated. In addition, interfacial reaction mechanism of the La 2 O 3 -doped Y 2 O 3 crucible materials and TiAl alloys, together with oxygen content of TiAl alloys were discussed. Solid solution of La 3+ in the crystal lattice of Y 2 O 3 significantly improved sintering properties of the La 2 O 3 -doped Y 2 O 3 crucible materials and decreased the open porosity. Compared with pure Y 2 O 3 , when adding 15 wt% La 2 O 3 , the open porosity and strength retention ration after thermal shock test of the La 2 O 3 -doped Y 2 O 3 crucible materials changed from 10.8% to 3.9% and from 64% to 78%, respectively. The interfacial reaction between La 2 O 3 -doped Y 2 O 3 crucible materials and TiAl alloys belongs to physical dissolution, and no reaction products were found during the melting of TiAl alloys. When using the 15 wt% La 2 O 3 -doped Y 2 O 3 crucible materials to melt TiAl alloys, oxygen content of the TiAl ingot declined to 530 ppm, which was only one fourth of that using pure Y 2 O 3 materials.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2023
·
IF 2.8
Ji Yaxiong,Lin Shuang,Xu Guihong,Chen Tianen,Gong Jianchao,Meng Fanbin,Wang Yuanhao
Abstract Catalytic conversion of CO 2 to methanol with H 2 from renewable energy has attracted increasing interest as a promising strategy for reducing excessive CO 2 emissions. However, the performance of reported various catalysts still suffers from low methanol yield with a passable CO 2 conversion. In this work, Cu–ZnO–La 2 O 3 interfaces are constructed with various La 2 O 3 mole ratio. Compared to Cu/ZnO, the optimized catalyst (i.e., Cu 0.6 Zn 0.2 La 0.4 ) exhibits a much higher mass-specific methanol formation rate (159.3 g MeOH /kg cat /h) at 240 °C and 3 MPa. A series of ex-situ and in-situ characterizations, such as X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N 2 O titration measurements, and in-situ diffuse reflectance Fourier transform infrared spectroscopy ( in-situ DRIFTS) study, are used to investigate its structure and mechanism study. The dispersion of Cu over Cu/ZnO/La 2 O 3 catalyst is significantly enhanced, forming more Cu–ZnO–La 2 O 3 interfaces. LaO x species favor CO 2 activation and generate more carbon intermediates species for CO 2 hydrogenation. Furthermore, more Cu + is bonded, which stabilizes the key intermediate, inhibits its desorption, and facilitates its further hydrogenation to methanol. This work is expected to offer an effective strategy to develop new catalysts with high performance for CO 2 hydrogenation to methanol. Graphical Abstract
研究领域:
催化化学
·
能源化学
·
材料科学
✓ 已验证
DOI
高影响因子
WATER ENVIRONMENT RESEARCH
·
2023
·Vol. 95
·期 5
·e10874
·
IF 3.1
Kai Su,Lin-xiao Li,Zhuo Zeng,Xue Yang,Qin Wang,Rong Cao,Cheng Yang,Han Zhang,Jun-min Chen,Wen-ya Tang,Xin Lin
La 2 O 3 and CeO 2 , as main rare earth oxides, with unique physical and chemical properties have been widely used in catalyst and grinding industry. In this study, the effects of La 2 O 3 and CeO 2 on the anaerobic process were investigated. The biological methane production tests showed that 0–0.05 g/L La 2 O 3 and 0–0.05 g/L CeO 2 enhanced anaerobic methanogenesis process. The result showed maximum specific methanogenic rates of La 2 O 3 and CeO 2 were 56.26 mL/(h·gVSS) and 49.43 mL/(h·gVSS) and, compared with the control, increased 4% and 3%, respectively. La 2 O 3 significantly reduced the accumulation of volatile fatty acids (VFAs), whereas CeO 2 had no similar effect. Dissolution experiments demonstrated that the content of extracellular La in the anaerobic granular sludge reached 404 μg-La/g volatile suspended solid (VSS), which was 134 times higher than that of extracellular Ce (3 μg-Ce/gVSS). The content of intracellular La reached 206 μg-La/gVSS, which was 19 times higher than that of intracellular Ce (11 μg-Ce/gVSS). The different stimulation between La 3+ and Ce 3+ could be attributed to the different dissolution of La 2 O 3 and CeO 2 . The result of this work is helpful to optimize anaerobic processes and to develop novel additives. Practitioner Points Novel anaerobic additives were developed. La2O3 and CeO2 in 0–0.05 g/L enhanced organics degradation and methane production. The addition of La2O3 significantly reduced the accumulation of volatile fatty acids. The solubilization of La2O3 was stronger than CeO2. The promoting effects of low concentrations of La2O3 and CeO2 were derived from dissolved La and Ce.
研究领域:
环境工程
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Mengen Hu,Lei Liu,Zhen Wang,Xian Dang,Chengwan Yang,Xinyang Li,Ming Li,Xiaoye Hu,Yue Li,Zhulin Huang,Xinghong Zhang
The pure phase and ultrafine WB 2 powders were successfully synthesized using a liquid phase precursor synergized with boro/carbothermal reduction method. Subsequently, dense WB 2 -SiC composites (99.5%) were fabricated through hot pressing sintering. The effects of La 2 O 3 additive on the densification, mechanical properties, and ablation resistance of WB 2 -SiC composites were systematically investigated. The ablation behavior of the composites was evaluated using a plasma flame. The results indicate that the mass ablation rate of WB 2 -SiC-La 2 O 3 is 0.463 mg/s, and the linear ablation rate is 0.311 μm/s when exposed to a 2273 K plasma flame for 60 s. The excellent ablation resistance is attributed to the reaction between La 2 O 3 and SiO 2 at high temperature, which generates La 2 Si 2 O 7 , effectively pinned in the glassy phase to inhibit the volatilization of B 2 O 3 . Furthermore, La 2 O 3 also reacts with B 2 O 3 and SiO 2 to generate a highly viscous B-Si-O-La protective layer, which blocks the ingress of oxygen.
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
Catalysis Science & Technology
·
2019
·Vol. 9
·期 13
·3454-3468
·
IF 5.726
Huixian Zhong,Jiaming Wang,Kang An,Kegong Fang,Yuan Liu
A catalyst with a novel composition for direct ethanol synthesis from syngas was prepared and investigated in this work, which is Rh nanoparticles (NPs) highly dispersed on La2O3 modified LaFeO3, and the Rh NPs/La2O3–LaFeO3 was loaded on SiO2 with high surface area. The catalyst was prepared by using LaFe1−xRhxO3 in the perovskite phase as the precursor, which was transformed to Rh/La2O3–LaFeO3/SiO2 after reduction. The results showed that, compared to Rh–La2O3/SiO2, the activity and selectivity to ethanol were improved markedly, which was ascribed to the well-matched catalyzing process by the active sites of Rh0, Rh+ (or Rhδ+) and the oxygen vacancies on the surface of LaFeO3; of those, Rh0 dissociatively adsorbed CO and the latter two associatively adsorbed CO. Moreover, the interaction of La2O3 and LaFeO3 donated electrons to rhodium, which effectively adjusted the ratio of CO adsorbed associatively and dissociatively, and thus improved the selectivity to ethanol and lowered the selectivity to methanol. The catalyst also exhibited excellent resistance to the sintering of Rh NPs and to carbon deposition, which was attributed to the confinement of Rh NPs by La2O3 and LaFeO3, the eliminating effect of La2O3 and LaFeO3 and the very high dispersion of Rh NPs.
研究领域:
催化化学
·
材料科学
✓ 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）