RSC Advances
·
2018
·Vol. 8
·期 30
·16947-16956
·
IF 2.936
Feng Nan,Kaihe Zhou,Shuan Liu,Jibin Pu,Yunhui Fang,Wenxuan Ding
Attapulgite is a layered silicate with good friction-reduction and self-repairing properties. In order to further improve its tribological properties, the present work mainly focuses on the preparation of attapulgite/La2O3 nanocomposite and study on its tribological behaviors. The tribological properties of mineral lubricating oil (150SN) containing attapulgite/La2O3 nanocomposite were investigated through an Optimal SRV-IV oscillating friction and wear tester. The rubbing surfaces and generated tribofilms were characterized by SEM, EDS, XPS and nanoindentation. Results indicated that the friction-reducing ability and antiwear property of the oil were both remarkably improved by attapulgite/La2O3 nanocomposite. A tribofilm mainly composed of Fe, Fe3C, FeO, Fe2O3, FeOOH, SiO, SiO2 and organic compound was formed on the rubbing surface under the lubrication of oil with attapulgite/La2O3 nanocomposite. The tribofilm possess excellent self-lubricating ability and mechanical properties, which is responsible for the reduction of friction and wear.
研究领域:
材料科学
·
摩擦学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL PHYSICS LETTERS
·
2020
·
IF 2.029
Xiangan Zeng,Li Liu,Yifeng Lv,Bing Zhao,Xiangnan Ju,Suyan Xu,Jianxia Zhang,Chunxia Tian,Dan Sun,Xiaonian Tang
La 2 O 3 -In 2 O 3 composited beaded nanotubes (LIBNTs) and pure In 2 O 3 nanotubes (INTs) were fabricated via a simple electrospinning method. By means of SEM, XRD and XPS analysis, we determined the surface structure, crystal phase and chemical properties of the materials. By test, we determined that the optimum operating temperature of LIBNTs-based sensor was a low temperature of 128 °C. The test results also revealed that LIBNTs-based sensor has an ultra-sensitive response to formaldehyde (101.9/50 ppm) and a faster response/recovery property (3 s and 19 s) compared with INTs-based sensor. The LIBNTs-based sensor also exhibited good linearity, repeatability and selectivity.
研究领域:
材料科学
·
环境科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
FUSION ENGINEERING AND DESIGN
·
2023
·
IF 1.7
Chan Wang,Ping Wang,Qing Yu Hou,Zhi Qiang Cui,Ning Fei Zhang,Lai Ma Luo,Zhen Yi Huang
In the present work, the feasibility and effectiveness of fabricating La 2 O 3 -doped W-based bulk using W-based composite powders of core-shell structure with W particle as a core and La(OH) 3 as a shell, without hydrogen reduction treatment, was evaluated. La(OH) 3 was first coated on the surface of pure W (uncoated) powders at a weight percentage of 3.50% to prepare composite (coated) powders using the electroless plating method. The uncoated and coated powders without being treated by hydrogen reduction were then sintered using spark plasma sintering (SPS) to fabricate bulks. The results showed that the core-shell structure with W particle as a core and La(OH) 3 film as a shell was fabricated. La 2 O 3 -doped W-based bulk with about 2.93 wt.% La 2 O 3 was obtained because of the transformation from La(OH) 3 to La 2 O 3 . The La 2 O 3 particles with larger sizes were distributed mainly at W grain boundaries and those with smaller sizes were distributed mainly inside W grains. The major densification mechanism of the sintered bulk from coated powders was the filling effect of La 2 O 3 particles on the pores as compared with the sintered bulk from uncoated powders, which could be evaluated by using a two-ball sintering neck model. The relative content of O in the form of WO 3 in the sintered bulk from coated powders was identical to that in the sintered bulk from uncoated powders. The W grain size of the sintered bulk from coated powders was smaller than that of the sintered bulk from uncoated powders. The thermal properties, mechanical properties, and irradiation properties of the sintered bulk from coated powders were all higher than those of the sintered bulk from uncoated powders. With the increase of sintering temperature, the evolution of the coated powders in the initial sintering period could be divided into six stages that were not completely independent and occurred in approximate sequence from the perspective of simplification. It was feasible and effective to fabricate La 2 O 3 -doped W-based bulk using the precursor W-based composite powders of core-shell structure with W particle as a core and La(OH) 3 as a shell without being treated by hydrogen reduction.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2022
·
IF 9.221
Qianchun Zhang,Yuxian Zhao,Xuan Shang,Shan Tang,Li Jiang,Yun Wu,Qin Zhou,Shiqin Li
Methallyl alcohol (MA), which is a common volatile organic compound, in vapor form can cause respiratory irritation, headache, nausea, and vomiting. Therefore, the development of a highly selective, excellently sensitive, and efficient sensor for rapidly identifying trace MA is essential. In this study, a La 2 O 3 /α-Al 2 O 3 composite with excellent cataluminescence (CTL) activity in the presence of MA was successfully synthesized. The CTL sensor based on as-prepared La 2 O 3 /α-Al 2 O 3 exhibited high selectivity for MA vapor as well as response and recovery times of 1 and 6 s, respectively. Under the optimal conditions for MA detection, the La 2 O 3 /α-Al 2 O 3 sensor exhibited a linear range of 0.0025–0.50 mg/L (correlation coefficient, R 2 = 0.998) and a low limit of detection of 0.61 μg/L at a signal-to-noise ( S/N ) = 3. The La 2 O 3 /α-Al 2 O 3 sensor was also used to determine the MA content in spiked samples and volatile gases generated from a medicine cabinet. Excellent recoveries in the range of 82.5–107% were obtained, with a corresponding relative standard deviation ( n = 5) in the range of 2.1–4.7%. Furthermore, the CTL sensing mechanism was investigated through density functional theory and high-performance liquid chromatography-ultraviolet analyses.
研究领域:
环境科学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2024
·
IF 6.9
Kai Su,Lin-xiao Li,Zhuo Zeng,Xue Yang,Tao Lei,Han Zhang,Qin Wang,Rong Cao
Industrial wastewaters, generated from such as abrasive and catalyst-producing processes, usually contain rare earth oxides: La 2 O 3 and CeO 2 . When employing anaerobic methanogenesis technology to treat these industrial wastewaters, the impacts of La 2 O 3 and CeO 2 cannot be ignored. This study thoroughly investigated the long-term effects of La 2 O 3 or CeO 2 in high-rate anaerobic expanded sludge bed (EGSB) reactors. When compared to the control reactor, it was found that the addition of La 2 O 3 led to an 11% decrease in chemical oxygen demand (COD) removal efficiency and 38% decrease in methane production rate ( MPR ). Similarly, the introduction of CeO 2 resulted in a 9% in COD removal efficiency and a 17% decrease in MPR . Both La 2 O 3 and CeO 2 had positive influences on enhancing methanogenic activity of anaerobic granular sludge (AnGS). Through the results of quantitative polymerase chain reaction (qPCR) and high-throughput sequencing analysis, it was revealed that La 2 O 3 and CeO 2 contributed to a balanced microbial community by promoting the growth of methanogens and suppressing anaerobic propionate and butyrate-producing bacteria. Meanwhile, La 2 O 3 and CeO 2 stimulated the proliferation of electroactive species: Geobacter and Methanospirillum . However, the results of quantification and characterization of Extracellular Polymeric Substances (EPS) of AnGS showed both La 2 O 3 and CeO 2 reduced the presence of tryptophan substances in EPS and decreased the protein/polysaccharide ratio. This led to the disintegration of AnGS into smaller zoogloea complexes. The findings of this study offer valuable insights for early-warning and optimization of anaerobic methanogenesis treatment in dealing with industrial wastewater containing La 2 O 3 and CeO 2 .
研究领域:
环境工程
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Zhen Cheng,Binbin Feng,Zhu Chen,Jie Zheng,Jing Li,Shufeng Zuo
La 2 O 3 modified silica-pillared clays (SPC) was synthesized by a soft template method. Both the basal spacing and the specific surface area increased after pillaring and modification, and the thermal stability was also improved, all of which could reduce the mass transfer resistance and improve the adsorption capacity of benzene. PtO x nanocrystalline catalysts were prepared by a high-temperature liquid reduction method. Among them, the catalyst with 0.2 wt% Pt loading and a La/KSF molar ratio of 0.5:1 (0.2% Pt/LaSPC (0.5:1)) showed the highest catalytic combustion activity and higher CO 2 selectivity, and the reaction temperature for benzene combustion was about 200 °C. Besides, the Pt 0 , Pt 2+ and Pt 4+ with particle sizes of about 3–5 nm coexisted on the surface of LaSPC (0.5:1). And this catalyst also exhibited good stability during the 100 h continuous reactions at 195 °C. The high dispersion of Pt particles, active oxygen species and strong redox property are responsible for the high activity of 0.2% Pt/LaSPC (0.5:1) for benzene combustion.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Zhen Zhao,Lei Zhang,Hongming Zhang,Wuhong Xin,Xiaowen Wang,Chunmiao Liu,Yang Guo,Yinghua Zhuang,Wanli Jiao
Investigating high-performance and low-energy consumption H 2 S sensors has become a hot research topic. This study adopted a one-step co-precipitation method to synthesize La-doped ZIF-8 deprotonating zinc acetate, lanthanum nitrate, and 2-Methylimidazole in an aqueous. La 2 O 3 /ZnO were synthesized with different La 3+ doping concentrations (0, 0.5, 1, and 1.5 at%). We found that La 3+ doping at a concentration of 1 at% showed the highest response value of 140 for 5 ppm H 2 S, at a low operating temperature of 100 °C, which is 2.4 times higher than that of pure ZnO. Additionally, La 3+ doping led to a lower detection limit of 1.9 ppb. The enhanced performance can be attributed to the widening of the difference in electron concentration, the increase in vacant oxygen content, and the spillover effect of H 2 S sensing. These factors were analyzed in detail by means of porosity, P-N heterojunctions, and the increased in adsorbed oxygen content caused by La 3+ doping.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Huilu Guo,Xiaojian Mao,Jian Zhang,Run Tian,Shiwei Wang
Attempts have been made to manufacture AlON transparent ceramics at low temperature using a new sintering aid system, Y 2 O 3 -La 2 O 3 -MnO. The sintering behaviors, including relative density and microstructure evolution of AlON ceramics doped with Y 2 O 3 -La 2 O 3 , MnO alone, and Y 2 O 3 -La 2 O 3 -MnO were compared. It was found that both the relative densities and grain sizes of samples doped with Y 2 O 3 -La 2 O 3 -MnO were much higher and larger than those of samples doped with Y 2 O 3 -La 2 O 3 or MnO alone, respectively. A liquid phase containing Al, O, N, Mn, and La formed at high temperature and played an important role on both eliminating pores and promoting grain growth of the sintered AlON bodies. Finally, translucent AlON ceramics were obtained through pressureless sintering at 1830 °C for 1 h, ~100 °C lower than those with conventional sintering aid Y 2 O 3 -La 2 O 3 . The ceramics doped with MnO showed green emission at 534 nm, under 445 nm excitation. We believe Y 2 O 3 -La 2 O 3 -MnO is a promising additive for the preparation of AlON transparent ceramic at lower temperature.
研究领域:
材料科学
·
陶瓷工程
·
光学材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Wenzhuo Xue,Zilong Xiong,Yupeng Chen,Feihu Tan,Hongyu Yu
High frequency performance and the content of glass are the direct factors affecting the performance of LTCC . In order to reduce the content of glass and improve the performance, we conducted a systematic study on the composition regulation of B 2 O 3 -La 2 O 3 -ZnO (BLZ) glass. Glass with low softening point is helpful for LTCC to achieve compact structure. DSC shows that the softening point of BLZ glass can be reduced from 580 ℃ to 537 ℃ by adjusting the composition. XRD analysis indicate that the glass and Al 2 O 3 formed ZnAl 2 O 4 interfacial phases. Combined with the thermal shrinkage curve, it can be proved that the softening of glass and the formation of interfacial phases are the reasons for the shrinkage and densification of LTCC. The lowest coefficient of thermal expansion of 2.878 ppm/℃ was obtained, and the minimum loss of LTCC is 0.00277 at 15 Ghz. These properties are making LTCC more suitable for high-frequency applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Yilin Wang,Yuping Chen,Shuang Yao,Furong Zhao,Linxiu Dai,Xian Yang,Changhua An
Electrochemical CO2 energization represents a promising strategy to mitigate its emission and promote resourceful utilization. The production of alcohols offers a sustainable pathway for converting CO2 into value-added chemicals, which is often hindered by low selectivity and high overpotential. In this work, a class of ultrasmall La2O3 nanoparticle-modified Cu2O-based catalyst has been synthesized in situ on a copper foam substrate through a simple hydrothermal method. The optimized catalyst demonstrated a high ethanol Faradaic efficiency of 51.7% at −1.0 V versus the reversible hydrogen electrode (RHE); simultaneously, syngas (CO/H2) was generated with Faradaic efficiencies of 28.27% for CO and 4.8% for H2. This product distribution characteristic enables efficient separation and utilization of both liquid (ethanol) and gaseous (syngas) products. This study highlights the pivotal role of rare earth elements in enhancing CO2RR efficiency by stabilizing reaction intermediates for facilitating C–C coupling. Furthermore, it presents a scalable and cost-effective approach for CO2 energization, paving the way for sustainable green energy production and carbon resource management.
研究领域:
电化学
·
纳米材料
·
能量转换
·
环境科学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY
·
2019
·Vol. 64
·期 11
·1464-1468
·
IF 0.822
Kangkang Yuan,Jin Xiaotong,Wang Xinqiang,Zhang Guanghui,Zhu Luyi,Xu Dong
Abstract ZrO 2 ceramic fibers have gained widespread study for the high temperature stability, low thermal conductivity and high mechanical properties. While for oxide fibers, grain growth is one of the limiting factors for long-term high temperature applications. In the present study, polycrystalline ZrO 2 –6 mol % Y 2 O 3 ceramic fibers with the addition of ~0–5 mol % La 2 O 3 to refine the grain size were fabricated by the dry-spinning method. The XRD and Raman spectral results showed that the pyrochlore La 2 Zr 2 O 7 phase was formed as a second phase in the tetragonal zirconia fiber matrix. The formation of a second phase was an effective way to hinder grain growth for the competition phase effect and solid solution mechanism. With the addition of La 2 O 3 , the grain size decreased and concentrated in a smaller range of 50–250 nm compared with the ZrO 2 –6 mol % Y 2 O 3 matrix at 1400°C. Furthermore, the thermal conductivity of the fibers decreased with the additive of La 2 O 3 less than 3 mol %. The present system is a promising candidate for high temperature applications.
研究领域:
材料科学
·
陶瓷材料
·
高温材料
·
纤维材料
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2018
·Vol. 24
·期 12
·4055-4061
·
IF 2.347
Wu Kezhong,Zhao Jiajing,Xiong Yuanyuan,Ruan Bei,Wu Mingxing
Pt-free composite counter electrode (CE) composed of La 2 O 3 was successfully synthesized by a simple pyrolysis of Lanthanum acetate hydrate (La(CH 3 COO) 3 ·xH 2 O) in a high-temperature solid phase. Furthermore, three proportion composite catalysts of La 2 O 3 @MWCNTs based on La 2 O 3 and multiwall carbon nanotubes (MWCNTs) were prepared and characterized as Pt-free catalysts for CE in dye-sensitized solar cells (DSSCs). The morphology and structure of La 2 O 3 @MWCNT composites were determined by scanning electron microscopy and X-ray diffraction. The electrochemical performance of La 2 O 3 @MWCNT composite catalysts for CEs was determined by photocurrent-voltage measurements, cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization. The experimental results showed that the power conversion efficiencies of 5.20, 5.12, and 4.70% were obtained for La 2 O 3 : MWCNTs with mass ratios of 5:1, 3:1, and 1:1 as counter electrode towards the reduction of I 3 − /I − ions respectively in the encapsulation of DSSC batteries, which were higher than that of MWCNTs (3.94%) and La 2 O 3 (0.77%) electrode under the similar conditions. The enhanced electrode performance was attributed to relatively larger surface area and higher conductivity of La 2 O 3 @MWCNT composite catalysts.
研究领域:
材料科学
·
能源科学
✓ 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）