JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 102
·期 10
·6194-6201
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IF 3.094
Shunhang Wei,Shu Jin,Guoxiang Pan,Zuxin Li,Gang Liu,Xiaoxiang Xu
Although BaNbO 2 N has visible light absorption as far as 740 nm, its photocatalytic activity is generally very poor under ordinary conditions, being incommensurate to its light absorption properties. In this work, we introduce Ca into the B site of BaNbO 2 N to form a complex perovskite BaNb 1− x /3 Ca x /3 O 2+ y N 1− y (0 ≤ x , y ≤ 1). The presence of Ca in BaNbO 2 N has great impact on a number of important properties such as band gap value, nitrogen content, surface hydrophilicity, and defects levels. In particular, defects such as Nb 4+ species are effectively suppressed in Ca-modified BaNbO 2 N. More importantly, photocatalytic activity of BaNbO 2 N for water oxidation reactions is substantially improved after Ca modifications. Compared with pristine BaNbO 2 N, more than twofold enhancement in photocatalytic oxygen evolution is observed for BaNb 0.8 Ca 0.2 O 2+ y N 1− y ( x = 0.6). Such improvements probably stem from the suppression of Nb 4+ species in the structure as well as enhanced surface hydrophilicity after Ca modification. The facile approach by incorporating alkaline earth cations into crystal structure can be well extended to other perovskite oxynitrides whose photocatalytic activity is subject to those defective species.
研究领域:
材料科学
·
光催化化学
✓ 已验证
产品关联
DOI
高影响因子
Solar RRL
·
2020
·Vol. 5
·期 3
·2000620
·
IF 7.527
Liuxu Yu,Xiangzhao Zhang,Guiwu Liu,Jian Yang,Wenkui Cao,Junlin Liu,Guanjun Qiao
Good thermal shock resistance and high absorptivity in a wide spectral range, as the two key aspects of photothermal coating in high-temperature applications, are seldom realized simultaneously. Herein, it is reported that a reticular porous Ca-doped LaCrO 3 perovskite photothermal coating fabricated by a simple process presents excellent thermal shock resistance between 1200 °C and room temperature and optical absorptivity of ≈94% in the wavelength range of 0.3–14 μm. The high-temperature sintering after screen printing triggers significant variations in the microchemistry and microstructure of the Ca-doped LaCrO 3 coatings, and the experimental analyses and the first-principles calculation demonstrate that the appropriate doping of Ca 2+ causes lattice distortion, decreases the lattice parameters and bandgap, and effectively enhances interactions between the photon and carrier, resulting in the high optical absorptivity in the visible, near-, and mid-infrared ranges. The reticular porous microstructure and interfacial diffusion bonding between the coating and Al 2 O 3 substrate with a gradient transition layer contribute to the high-temperature thermal shock resistance. Herein, a novel way to fabricate a high-performance and low-cost photothermal conversion coating is provided, which presents a broad application prospect in energy harvesters and sensors.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Ying Zhang,Jun Li,Fan Zhang,Xiao Li,Baige Yuan,Manman Xia,Peng Zhao,Ruyan Lei
Doping elements play an important role in improving the conductivity of Li 4 Ti 5 O 12 used as anode materials for lithium ion batteries . In this work, nanoparticles of Li 4-X Ca x Ti 5 O 12 (x = 0, 0.03, 0.05 and 0.07) were successfully synthesized through a facile hydrothermal method followed by calcination . The evolution in microstructure as well as electrochemical performance of the modified samples with the doped Ca content were investigated in details. It was found that modified Li 4-x Ca x Ti 5 O 12 (x = 0.05) exhibited the best electrochemical performances in terms of the highest initial specific discharge capacity (158.55 mA h g −1 at 160 mA g -1 ), best cycling stability with a retained specific charge capacity of 104.76 mAh g −1 at 160 mA g -1 after 100 cycles and rating capability with a retained rate of 64.55 %/88.56 % with the current density drastically increased 1600 mA⋅ g −1 and dropped to initial value. The excessive introduction of Ca (x = 0.07) caused the sharp decrease in electrochemical performance due to the formation of inert and insulating CaCO 3 . Li 4-x Ca x Ti 5 O 12 (x = 0.05) also demonstrated a lowest ohmic resistance (2.35 Ω) and charge transfer resistance (95.42 Ω).
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yong-Hui Zhang,Zuo-Bei Wang,Adenike Bernice Eloise Adeoye,Yi-Fan Wang,You-Gui Huang,Xin Ye,Wei Wang
Lanthanum (La) adsorbents are highly effective for phosphorus removal but are constrained by their high reagent cost because of their La content. By exploiting the similarity in ionic sizes between Ca 2+ and La 3+ , we develop a low-cost composite adsorbent LCCa-5@Dia by doping La 2 (CO 3 ) 3 ·8H 2 O with Ca 2+ . Our results indicate that the slow addition of NaHCO 3 during the synthetic process facilitates the incorporation of Ca 2+ into the La 2 (CO 3 ) 3 ·8H 2 O lattice, leading to an adsorption behavior nearly identical to that of the undoped adsorbents. LCCa-5@Dia demonstrates a high adsorption capacity of 60.04 mg P/g, with stable performance across a pH range of 3 to 11. Its adsorption property also exhibits excellent stability under the interference of solution pH and competing ions. Materials characterization reveals that the adsorption occurs through electrostatic attraction and ligand exchange. In continuous column-adsorption experiments, the LCCa-5@Dia adsorbent treats up to 4000 bed volumes of simulated low concentration wastewater (1.7–2.7 mg P/L). This translates to a treatment cost as low as $0.0211/m 3 . Meanwhile, the adsorbent also maintains over 80 % of the adsorption capacity after three regeneration cycles. The excellent performance and low treatment cost of the calcium-doped lanthanum carbonate adsorbents highlight its practical potential in treating low concentration wastewater.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yichen Yu,Yuanbing Li,Shujing Li,Tenglong Guo,Zhe Qiao,Changdong Wei
Monoclinic barium aluminosilicate (celsian) shows application potential owing to its high-temperature resistance, low thermal conductivity, and excellent oxidative reduction properties. Hexacelsian can easily undergo nucleation because of its favorably symmetric crystal structure, resulting in faster precipitation compared to than in the case of celsian. Celsian can only be formed through the sluggish transformation of hexacelsian at high temperatures. In this study, celsian doped with different contents of CaO was synthesized through a simple one-step solid-state reaction process at lower temperatures and in a shorter time and investigated using differential thermal analysis, phase characterization, microstructural observation, and FactSage thermodynamic calculations. Results showed that the addition of CaO could promote the solid-state reaction, affording products such as barium silicate, hexacelsian, and celsian at lower temperatures. Moreover, CaO could promote the synthesis of celsian in the form of solid solution, affording fully monoclinic celsian Ba 0.7 Ca 0.3 Al 2 Si 2 O 8 with only 3 h of holding time at 1400 °C. The optimal addition of CaO showed a decreasing trend with the increase in heat treatment temperature. An optimum CaO level of 0.1 ≤ x ≤ 0.3 was recommended to stabilize celsian. The effects of CaO addition and temperature on the physical, mechanical and thermal conductivity properties of Ba 1-x Ca x Al 2 Si 2 O 8 were investigated, and Ba 1-x Ca x Al 2 Si 2 O 8 also exhibited excellent antioxidant reduction properties.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2020
·Vol. 18
·期 3
·684-696
·
IF 1.762
Zhengkun Cai,Minjin Jiang,Qianqian Guo,Xiaosong Jiang,Song Chen,Hongliang Sun
High-density chromium deficient calcium-doped lanthanum chromite-based ceramics (La 0.8 Ca 0.2 Cr 0.98 O 3 ) were prepared by hot pressing (HP) at different sintering pressures, and the highest density can reach 98.8%. The effects of sintering pressure on the microstructure, mechanical properties, and electrical conductivity of La 0.8 Ca 0.2 Cr 0.98 O 3 materials were studied. The experimental results show that HP can increase the density of lanthanum chromite-based ceramic materials and significantly inhibit the growth of grain size. As the sintering pressure increases, the strength and hardness gradually increase, but the fracture toughness decreases. When the sintering pressure is greater than 58 MPa, the presence of the second phase CaCr 2 O 4 can be detected in the XRD results of the sintered ceramics. The SEM results showed that CaCr 2 O 4 had two completely different morphologies in the sintered ceramics, and it was initially speculated that the possible causes were due to two different generation pathways. The electrical conductivity decreases with increasing sintering pressure, whereas the maximum electrical conductivity obtained is 18.61 S/cm in vacuum at 800°C for pressureless sintering ceramic.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
Nano-Micro Letters
·
2021
·Vol. 14
·期 1
·1-12
·
IF 16.419
Zhu Mengya,Li Guangyong,Gong Wenbin,Yan Lifeng,Zhang Xuetong
A calcium-doped boron nitride (Ca-BN) aerogel was synthesized by introducing Ca into crystal structure of BN building blocks.
The aerogels exhibited superior high-temperature stability and could resist the burning of butane flame (~1300 °C) in air atmosphere.
Ca-BN aerogel, together with Al foil, can effectively hide thermal target at high temperature up to 1300 °C.
研究领域:
材料科学
·
热学工程
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Changhui Zhao,Huimin Gong,Gaoqiang Niu,Fei Wang
Sensitivity and selectivity of metal oxide semiconductor-based gas sensors are two crucial criteria. In this work, a highly sensitive and selective ethanol sensor has been prepared based on Ca-doped In 2 O 3 nanotubes (Ca-In 2 O 3 NTs). The products were synthesized by a simple electrospinning method with subsequent annealing in air. The crystal structure and morphology of as-obtained products are obviously affected by Ca-doping levels (1–10 mol%). X-ray diffraction and electron paramagnetic resonance results reveal that some Ca dopants (≤3 mol%) can enter the lattice of In 2 O 3 with the decreasing grain size, and an enrichment of the oxygen vacancies. In contrast, the grain size of Ca-In 2 O 3 NTs increases dramatically with further increase of Ca concentration (7–10 mol%), and the excessive Ca dopants tend to form a new CaIn 2 O 4 phase. Gas-sensing measurements demonstrate that the Ca-In 2 O 3 sensors exhibit enhanced ethanol sensing properties with respect to the pure In 2 O 3 sensor. Especially, the 3% Ca-In 2 O 3 sensor shows the highest response (183.3, at 100 ppm) with the excellent selectivity for ethanol detection at 240 °C. Such sensitive and selective ethanol detection is mainly based on the “doping effect” of Ca 2+ ions, suggesting an effective route to develop the ability of In 2 O 3 based gas sensors.
研究领域:
材料科学
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传感器技术
·
纳米科技
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Sheng Guo,Haojie Wang,Wei Yang,Hussain Fida,Liming You,Kun Zhou
In this work, a cost-effective and eco-friendly calcium-doped α-Fe 2 O 3 (Ca-Fe 2 O 3 ) with abundant oxygen vacancies was fabricated using a scalable precipitation-calcination method to activate peroxymonosulfate (PMS) for wastewater purification. Density functional theory calculations revealed that the incorporation of Ca 2+ into the α-Fe 2 O 3 structure enhances the electron transfer from α-Fe 2 O 3 to PMS, facilitating the activation of PMS. The degradation of Rhodamine B by 5%Ca-Fe 2 O 3 proceeded with a reaction constant 8 times higher than that of pristine α-Fe 2 O 3 . This can be attributed to the increased generation of 1 O 2 and O 2 • − , increased specific surface area and enhanced electrical conductivity. The applicability of the 5%Ca-Fe 2 O 3 /PMS system was investigated including its operating parameters and stability, and the intermediates involved in the reaction were identified. The 5%Ca-Fe 2 O 3 /PMS system exhibited excellent degradation efficiency in natural water samples. This work opens up new perspectives for designing highly efficient catalysts and renders iron oxides potential candidates for environmental remediation.
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
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 29
·期 4
·6375-6388
·
IF 4.223
Ahmad Khalil,Shah Izaz Ali,Ali Sharafat,Khan Muhammad Tariq,Qureshi Muhammad Bilal Ahmed,Shah Syed Hassan Ali,Ali Asmat,Rashid Wajid,Gul Hifza Nayab
Ferric hydrate has been extensively applied for the removal of various types of pollutants from wastewater because of its low cost and high efficiency. However, its wide-scale application has been greatly restricted by high-dose and low-adsorption capacity. Therefore, a novel Ca-doped ferrihydrite adsorbent has been synthesized and used for the enhanced removal of fluoride from wastewater in the presence of other co-existing ions. At 5 mg/L initial fluoride concentration and pH 5, the removal efficiency of fluoride approached to 97.5% and remained stable. Similarly, with the increase of dose from 100 to 300 mg/L, the fluoride removal linearly increased to 98% and remained plateau at neutral pH. Also, the presence of co-existing ions such as NO 3 − , SO 4 2− , Cl − , and natural organic matter has not significantly influenced the removal performance of the adsorbent. Fluoride removal best fit the pseudo-second-order reaction kinetics and Langmuir isotherm model. The prepared adsorbent exhibited a maximum adsorption capacity of 53.21 mg/g for fluoride uptake from water. The SEM-EDX confirmed the doping of Ca onto the ferrihydrite where the elemental peaks of Ca and Fe emerged at the energy value of about 3.6 Kev and 7.1 Kev respectively in EDX analysis. In addition, SEM results of Ca-doped ferrihydrite adsorbent illustrated that a large microplates type of products was acquired after synthesis. The regeneration results confirmed that adsorbent could retain their original adsorption capacity after five regeneration cycles. The current study suggested that Ca-doped ferrihydrite has the application potential for the enhanced adsorption of fluoride from the water phase. Graphical abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2024
·Vol. 171
·期 8
·080526
·
IF 3.1
Xiaoning Li,Mengmeng Liu,Wenjuan Zhang,Yanli Zhang,Jiakun Zhou,Wenzhang Zhou,Naixin Wang,Weiwei Xu,Kehua Dai
O3-type NaNi0.4Fe0.2Mn0.4O2 cathode materials are structurally stable and have a high nickel content, allowing for stable high-capacity output. However, their performance needs further improvement. First, we investigated the effects of different sodium contents on the structure, morphology, and electrochemical performance of NaxNi0.4Fe0.2Mn0.4O2(x = 0.85, 0.9, 0.95, 1, 1.05) materials. The Na0.9Ni0.4Fe0.2Mn0.4O2 material exhibited initial discharge specific capacities of 148.11 and 181.80 mAh·g−1 at voltage ranges of 2–4.1 V and 2–4.2 V, respectively. To further optimize the cycling performance of the material, we doped NaNi0.4Fe0.2Mn0.4O2 with different calcium contents. Ca2+ doping significantly enhanced the electrochemical performance of the material. Subsequently, we synthesized Na0.96Ca0.02(NMF)0.95Zn0.05O2, and the dual-doped NMF-Ca0.02Zn0.05 maintains approximately 80% capacity retention at 1–4.05 V, and around 70% as the cut-off voltage increases to 4.15 V in full cells.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Suwanan Thammarong,Xiaogang Yu,Peinan Yin,Renpeng Yang,Chengwei Wu,Wei Zhang
Magnetic induction hyperthermia has great potential in cancer treatment. However, the low heating efficiency of the magnetic nanoparticles (MNPs) with self-regulated temperature capability limits its clinical application. Here, the self-regulated temperature MNPs of Ca-doped Co-Zn ferrite MNPs (Ca x Co 0.5-x Zn 0.5 Fe 2 O 4 , 0 ≤ x ≤ 0.20), with high heating efficiency, were successfully synthesized by co-precipitation method followed by heat treatment. Noticeably, the x = 0.1 suspension sample can self-stabilize the temperature for high-temperature hyperthermia, whereas x = 0.2 suspension sample can self-stabilize the temperature suitable for conventional hyperthermia under an alternating magnetic field of 32 kA/m and 100 kHz. In vitro cell experiments indicate that the MNPs have good biocompatibility. The results demonstrate that optimized saturation magnetization ( σ S ) and tunable Curie temperature (Tc) enhance both the heating efficiency and thermal safety of the nanoparticles during magnetic induction hyperthermia treatment.
研究领域:
生物医学工程
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材料科学
·
肿瘤治疗
✓ 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）