APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
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2020
·Vol. 126
·期 4
·1-10
·
IF 1.81
Chen Yu,Dong Zegang,Xue Xinxin,Chen Song,Natan Avi,Lv Yu,Chen Cheng,Yang Yinye,Cen Weifu,Yang Yang
Pure SnO 2 and La-doped SnO 2 nanocomposite were prepared through hydrothermal method, and their gas sensing performances were studied. Results indicate that the sensing response of the 5 wt% La-doped SnO 2 nanocomposite reached 29.5 when exposed to 75 ppm methanol at the optimal operating temperature of 220 °C, which was over seven times larger than that of pure SnO 2 nanoparticles. In addition, the response and recovery time were shortened to 12 s and 7 s, respectively. Moreover, the 5 wt% La-doped SnO 2 nanocomposite presents a good selectivity toward methanol among methanal, methanol, ammonia, acetone and benzene gases. The improvement in the gas sensing properties of the 5 wt% La-doped SnO 2 nanocomposite toward methanol can be attributed to the smaller crystallite size, larger surface area and the modified chemical nature of nanocomposite surface.
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
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2017
·
IF 4.784
Ying Wu,Yuelin Wei,Qiyao Guo,Hui Xu,Ling Gu,Feiyue Huang,Dan Luo,Yunfang Huang,Leqing Fan,Jihuai Wu
A series La-doped WO 3 /SrTiO 3 heterojunctions photocatalyst were successfully prepared using solvothermal method . The as-fabricated heterostructures composite included La-doped WO 3 fluff spheres tightly grew on the surface of SrTiO 3 cubic particles. The crystallanity, structural, morphological and optical features of the catalysts were characterized using several techniques including XRD , XPS , SEM, TEM UV−vis and HRTEM. The photocatalytic activity of the heterojunction was evaluated by the photocatalytic degradation of methyl orange (MO) under visible-light irradiation. The influence of La doping and SrTiO 3 molar ratio on heterojunctions photocatalysts was investigated. Among the as-prepared photocatalysts, the LWS50 sample exhibited the highest photocatalytic activity , almost 100% MO were completely decomposed within 75 min under visible light irradiation (λ > 420 nm). Compared with the pure WO 3 and SrTiO 3 , the enhancement of photocatalytic activity was mainly attributed to the three-dimensional hierarchical structure and the effectively transfer and separation of photogenerated electron–hole pairs in La doped WO 3 and SrTiO 3 heterojunctions
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
JOURNAL OF SOLID STATE CHEMISTRY
·
2019
·
IF 2.291
Luyu Wang,Yunling Wu,Junkuo Gao,Jia Song
Solid AlPO-5 and La doped AlPO-5 (La/AlPO-5) were synthesized by a hydrothermal treatment followed by crystallization and calcination . The ammonia (NH 3 ) sensing properties of AlPO-5 and La/AlPO-5 were evaluated by using quartz crystal microbalance (QCM) platform to work out the enhanced effect of La doping treatment. La/AlPO-5 possessed a higher response to NH 3 than that of AlPO-5 with same concentration. In addition to the favorable sensitivity, La/AlPO-5 based sensor also showed prominent repeatability and selectivity. We also explored the thermodynamics and humidity-enhanced effect in the NH 3 sensing process.
研究领域:
材料科学
·
化学传感器
✓ 已验证
DOI
高影响因子
Materials Advances
·
2023
·Vol. 4
·期 3
·940-947
·
IF 5
Xiaobing Yang,Junjie Pan,Bingcong Xing,Wenjie Lei,Yingchun Fu,Kejun Cheng
Nowadays, aflatoxin B1 (AFB1) contamination is considered as one of the most common food safety issues for humans and animals. As one of the most advanced oxidation techniques, photocatalytic degradation can break down organic contaminants into nontoxic and harmless materials efficiently. In this paper, we explored the degradation efficiency of AFB1 by ZnIn2S4. To promote the photocatalytic degradation efficiency of AFB1, ZnIn2S4 was coupled with MIL-125(Ti) and then doped with La [this hybrid is denoted as La-ZnIn2S4/MIL-125(Ti)] to effectively convert it via photocatalytic generation of superoxide radicals (˙O2− and ˙OH) and achieve much enhanced photocatalytic performance, which is demonstrated by degrading 97.6% of AFB1. According to the transient photocurrent responses, the doping of La and coupling with MIL-125(Ti) can highly improve the efficient separation of the photoinduced electron–hole pairs on ZnIn2S4, leading to the effective conversion of OH− and O2 into ˙O2− and ˙OH, respectively, during the photodegradation process. This strategy of coupling with MOFs and doping with rare earth elements provides a facile and efficient method for degrading food pollutants produced by aflatoxins.
研究领域:
食品安全
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jiaming Wang,Huixian Zhong,Kang An,Qiang Liu,Wu Jin,Yuan Liu
In this work, Ni–Co alloy nanoparticles (NPs) on La-doped SiO2 showed excellent selectivity toward ethanol for direct ethanol synthesis via CO hydrogenation. Over the catalyst with an optimal ratio of Ni/Co, the total alcohol selectivity reached 33.5%, of which ethanol occupied 47.0 wt %. The results demonstrated that the interaction between Co and Ni improved the ability to activate H2 and CO and adjusted the amount of the dissociatively and associatively adsorbed CO. Besides, the mutual dilution of nickel and cobalt in Ni–Co alloy NPs effectively reduced the isolated Co or Ni-clusters; thus, the formation of heavy hydrocarbons was suppressed. In the reaction process, Ni@Co–Co2C, a core–shell composite with a nickel core and Co–Co2C shell, was formed, which suppressed the loss of nickel species. Moreover, with the reaction going on, a small amount of poorly alloyed Co-clusters would be covered gradually by the formed coke, resulting in an increase in alcohol selectivity.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Rui Cao,Langlang Wang,Xueqian Wang,Yibing Xie,Xiang Li,Ping Ning
The low-temperature conversion of corrosive carbonyl sulfide (COS) in steel by-product gas is essential for the clean utilization of this gas. Herein, La-Ti@K catalysts doped with La nanoparticles were shown to exhibit significant photopromoted thermocatalytic activity and stability under UV light irradiation. At a reaction temperature of 60 °C, the TOF value increased from 4.84 × 10 -4 s −1 (TiO 2 , thermal treatment) to 8.43 × 10 -4 s −1 (La-Ti@K, photothermal treatment), and the H 2 S selectivity exceeded 99%. This was because La doping increased the density of basic sites on TiO 2 , which promoted the continuous dissociation of H 2 O in the system and the regeneration of –OH under UV irradiation. Moreover, the photogenerated electrons from TiO 2 were transferred to La to maintain the metallic La nanoparticles, as well as to ensure the activation and photothermal hydrolysis of COS. The presence of a suitable electron-metal-support interaction (EMSI) between the electron-rich La nanoparticles and TiO 2 might be responsible for these phenomena. In addition, theoretical calculations revealed that light-induced electron transfer was conducive to H 2 O dissociation and COS activation, while La doping reduced the free energy of the hydrolysis reaction. This work demonstrates the effectiveness of La-Ti@K catalyst in COS photothermal hydrolysis and provides a theoretical basis for further understanding of the photothermal catalytic mechanism.
研究领域:
环境科学
·
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 6
·期 14
·5580-5589
·
IF 5.287
Zijian Feng,Jianqiang Wang,Xiao Liu,Yanwei Wen,Rong Chen,Hongfeng Yin,Meiqing Shen,Bin Shan
A series of LaxSm1−xMn2Oδ (x = 0, 0.1, 0.3, 0.5) catalysts were synthesized through a co-precipitation method. The catalytic activity for NO oxidation was enhanced with La substitution, and the maximum activity was achieved at x = 0.3. XRD and HRTEM results revealed the formation of a multiphase oxide as well as the interface structure between the mullite (SmMn2O5) phase and Mn-rich perovskite (La0.96MnO3.05) phase. The main impact of different La/Sm molar ratios is the amount of surface adsorbed oxygen (Oads) and surface Mn4+ ions as revealed by XPS results. The NO oxidation performance was enhanced through La addition by promoting the decomposition of nitrate/nitrite species and desorption of NO2, improving the reducibility of surface adsorbed oxygen, as determined by H2-TPR, NO + O2-TPRD and in situ DRIFTS studies. Mono-, bi-dentate and bridged nitrates formed on the surface were determined to be the primary reaction intermediates.
研究领域:
催化化学
·
材料科学
·
环境化学
·
表面科学
·
无机化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Zhenzhen Song,Yongcheng Zhang,Chaojing Lu,Zhenmeng Ma,Zhenjia Hu,Lin Wang,Chao Liu
Relaxor ferroelectric 0.75(Pb 1–3 x /2 La x )(Mg 1/3 Nb 2/3 )O 3 -0.25(Pb 1–3 x /2 La x )TiO 3 (La 3+ :PMN-PT x /75/25, where x =2.8, 3.0, 3.5, and 4.0 mol% of La 3+ ) transparent ceramics were fabricated by the combination of oxygen atmosphere pressureless sintering and hot-pressing sintering process. The optical transmittances of above four ceramics are higher than 60% at the wavelength of 500–900 nm. La 3+ :PMN-PT 3.0/75/25 exhibits the highest transparency around 70% at 900 nm which is very close to the theoretical transmittance 71%. Each of the four ceramics exhibits the pure perovskite phases. They show fully dense microstructures and their relative densities are higher than 99.8%. The ferroelectric and dielectric measurements indicate that these four ceramics exhibit relaxation characteristics. With increasing La 3+ content, (200) peak in XRD patterns shifts to higher angles and the average grain size increases, while the temperature Tε max corresponding to the maximum ε r , the remanent polarizations P r and coercive fields E c decrease gradually.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
PHYSICA B-CONDENSED MATTER
·
2022
·
IF 2.988
Shiyi Zhang,Dongyan Zhang,Yangxi Yan,Maolin Zhang,Zhimin Li,Pangpang Wang,Ri-ichi Murakami
Relaxor ferroelectrics are complex materials with properties that are remarkably different from traditional ferroelectrics, and they have the ability to probe frequency-dependent dielectric susceptibility. However, the empirical laws developed for traditional ferroelectrics also apply to relaxor ferroelectrics. Here we report an abnormally improved dielectricity of the La-doped relaxor ferroelectric 0.4PNN-0.6PHT, which does not linearly vary with the piezoelectric coefficient, as it is expected. A mesoscale mechanism is proposed to explain the origin of the improved dielectric response of 0.4PNN-0.6PHT, in which the alignment of polar nano regions facilitates the polarization response to the external field. This mechanism demonstrates the critical role of polarization fluctuation for the macroscopic properties of 0.4PNN-0.6PHT.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Shafqat Ullah,Yongqi Pan,Qiangqiang Xue,Tianyi Huang,Yizhi Hu,Runping Ye,Yujun Wang,Guangsheng Luo
CO 2 methanation has emerged as a key strategy for its potential uses and ability to alleviate climate change by reducing CO 2 emissions. Herein, we present a controllable and continuous improved coprecipitation catalyst preparation method employing a T-junction microreactor to investigate La doped Ni-CeO 2 catalysts. A series of catalysts was systematically synthesized, with Ni/CeLa (5:5) emerging as the most promising candidate, exhibiting 76 % CO 2 conversion at 250 °C and 60.5 mmol/g cat .h space–time yield of methane. Different structural characterization techniques, including in-situ Raman, Quasi in-situ XPS, in-situ DRIFTS, and DFT calculations were employed to unravel the structure activity mechanisms contributing to the enhanced catalytic performance. The findings indicate that the introduction of La as a dopant reduces particle size, promotes Ni dispersion, and increases interfacial sites. These enriched interfacial sites contribute a pivotal role in facilitating the adsorption and hydrogenation of bicarbonate species, ultimately leading to improved methanation performance. This study not only highlights the efficiency of the La doped Ni-CeO 2 catalyst, but it also gives valuable insights for chemical strategy to improve structure activity relationships and mechanism studies for efficient CO 2 methanation performance.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yin Hu,Wei Chen,Fen Zhang,Lingling Wang,Xuanye Chen,Fei Han,Weiguo Song
Photocatalytic degradation of aqueous organic pollutant while hydrogen evolution has become an attractive and potential approach to address environmental pollution and energy shortages. The design of highly efficient photocatalyst and the mechanism study are the keys for this issue. For this purpose, a series of rare earth La doped perovskite NaTaO 3 were prepared by an easy solid-phase synthesis method. La doping changed the morphology, structure and physicochemical properties of NaTaO 3 crystal. More importantly, it also found that controllable La dopants formed a concentration gradient between the surface and bulk of NaTaO 3 crystal, which would cause a gradient of energy band structure. Noteworthy, 0.5La/NaTaO 3 was identified as the intermediate state with the La doping from A sites to B sites and from bulk to surface in NaTaO 3 crystal. It possessed a large La concentration gradient, leading to the better photoelectrochemical properties and photocatalytic performance than any other xLa/NaTaO 3 catalyst. For the photocatalytic reaction over 0.5La/NaTaO 3 , HCHO was partially mineralized and gradually converted to HCOOH due to the large energy barriers of the intermediate reaction steps, while H 2 was produced stably in the five recycle runs. The active species of • O 2 − , •OH and h + were detected by the control experiments with trapping agents, and • O 2 − was confirmed to be the dominant one in the photocatalytic reaction. On this basis, the possible mechanism was proposed to understand the photocatalytic system in depth.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Mengjuan Cao,Mengkai Yang,Yanyan Xu,Yaqiu Sun,Hongming Sun
It is of great value to explore non-noble and highly active electrocatalysts for oxygen evolution reaction (OER) to obtain reproducible and clean fuels. In this work, a novel La-doped FeNiSe 4 /Fe 0.8 Ni 0.2 Se 2 /NF (La-FeNi-Se/NF) heterostructure catalyst was prepared by a facile selenization treatment to La-doped FeNi Prussian blue analogue(PBA) in-situ grown on foam nickel (NF). The catalytic performance of La-FeNi-Se/NF was significantly enhanced by the doped La 3+ . As a result, the optimized La-FeNi-Se-2/NF exhibits superior alkaline OER electrocatalytic activity (overpotential 158 mV at 10 mA cm −2 and Tafel slope 35.6 mV dec −1 ) than FeNi-Se/NF and Ln-FeNi-Se/NF (Ln = Ce, Gd, Yb), and most reported FeNi-based OER electrocatalysts. The excellent electrocatalytic capability to OER is attributed to the doping FeNi-Se heterostructure with a suitable amount La 3+ . Also, the unique La-FeNi-Se-2/NF flower-like structure composed of nanograins can produce abundant active sites and enhance charge transfer, thereby further improving the catalytic performance. This work highlights an effective chemical and engineering method to prepare efficient electrochemical catalysts.
研究领域:
材料科学
·
电化学
✓ 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）