Nanomaterials
·
2023
·Vol. 13
·期 4
·777
·
IF 5.3
Jianming Wang,Lu Chen,Bo Zhao,Chunyong Liang,Hongshui Wang,Yongguang Zhang
Lithium-sulfur batteries (LSBs), with their high theoretical specific capacity and energy density, have great potential to be a candidate for secondary batteries in the future. However, Li-S batteries suffer from multiple issues and challenges, for example, uneven growth of lithium dendrites, low utilization of the active material (sulfur), and low specific capacity. This paper reports a low-cost and anodic oxidation method to produce niobium pentoxide with a porous structure (P-Nb2O5). A simple one-step process was used to synthesize P-Nb2O5with porous structures by anodizing niobium at 40 V in fluorinated glycerol. The porous Nb2O5showed excellent rate capability and good capacity retention by maintaining its structural integrity, allowing us to determine the advantages of its porous structure. As a result of the highly porous structure, the sulfur was not only provided with adequate storage space and abundant adsorption points, but it was also utilized more effectively. The initial discharge capacity with the P-Nb2O5cathode rose to 1106.8 mAh·g−1and dropped to 810.7 mAh·g−1after 100 cycles, which demonstrated the good cycling performance of the battery. This work demonstrated that the P-Nb2O5prepared by the oxidation method has strong adsorption properties and good chemical affinity.Keywords:lithium-sulfur battery;niobium pentoxide;porous;cathode
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2021
·Vol. 26
·期 2
·449-456
·
IF 2.647
Liu Shanshan,Li Chenyao,Wang Dongxin,Li Junyi,Yuan Rui,Che Yusi,He Jilin,Song Jianxun
In this research, the reduction mechanism of Nb(V) under various [F − ]/[Nb n+ ] ratios ( α ) was investigated by a series of electrochemical techniques, such as square wave voltammetry (SWV) and chronopotentiometry (CP). We previously studied the electrode reduction process of Nb(V) and revealed that was Nb(V) → Nb(III) → Nb(I) → Nb in NaCl-KCl molten salt. It was found in this research that the electrode reduction process of Nb(V) ion was shortened to Nb(V) → Nb(III) → Nb when α was equal to 1.0; furthermore, the electrode reduction process of Nb(V) ion transforms to Nb(V) → Nb(IV) → Nb when α was greater than or equal to 5.0. Moreover, the reaction mechanism was also discussed in this work. Metallic niobium was collected on a molybdenum electrode under the condition of higher fluoride content after electrolysis in the melt.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
DENTAL MATERIALS
·
2021
·
IF 5.304
Danlei Zhao,Haoran Dong,Yuting Niu,Wenjie Fan,Muqi Jiang,Ke Li,Qingsong Wei,William M. Palin,Zhen Zhang
Objective Guided bone regeneration (GBR) techniques use barrier membranes to augment the alveolar ridge for the site-specific growth of bone defects. However, current approaches using cast metal substructures exhibit poor adaptation to the surgical site and increased risk of infection. This study aimed to fabricate multi-functional coatings with 3D-printed porous titanium-niobium (Ti-Nb) alloy meshes to maintain space, prevent the ingrowth of fibroblasts and inhibit the colonization of bacteria for GBR. Methods Ti-Nb alloy meshes were prepared by selective laser melting (SLM) and used as substrates for novel surface coatings. Porous chitosan (CS)/ gelatin (G)/ doxycycline (Dox) coatings were formed on the meshes using electrophoretic deposition (EPD) and freeze-drying. The process of EPD was characterized through Fourier transform infrared spectroscopy (FT-IR), zeta potential, and particle size analysis. The cytotoxicity of the coatings was evaluated through the culture of osteoblasts and immunostaining. The antibacterial activity of the coatings was tested using inhibition zone tests against Staphylococcus aureus ( S. aureus ) and scanning electron microscope (SEM). The inhibition of fibroblasts infiltration and nutrients transfer properties were analyzed using immunostaining and permeability tests. Results High yield strength (567.5 ± 3.5 MPa) and low elastic modulus (65.5 ± 0.2 GPa) were achieved in Ti-Nb alloy bulk samples. The data of zeta potential, FT-IR and SEM indicated that porous spongy coatings were chemically bonded following EPD. In vitro analysis of CSGDox1 (containing Dox at 1 mg·mL −1 ) coating revealed its antibacterial effect and biocompatibility. Moreover, the CSGDox1 coating was proved to be effective for preventing the ingrowth of fibroblasts, whilst allowing the infiltration of nutrients. Significance This study verified that the EPD of CSGDox coatings on the 3D-printed Ti-Nb meshes can maintain space, provide antibiotic release whilst maintaining a barrier against soft-tissue growth, which is essential for the success of GBR treatment.
研究领域:
生物材料学
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口腔医学
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组织工程学
✓ 已验证
DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2018
·Vol. 5
·期 5
·1126-1132
·
IF 5.106
Congjie Lv,Yi Peng,Jing Yang,Xiaochuan Duan,Jianmin Ma,Taihong Wang
Nb-Doped LiNi0.4Co0.2Mn0.4O2 (Nb-NCM) nanobelts have been successfully fabricated for the first time through a facile electrospinning method by the delicate control of PAN pyrolysis and Nb-NCM formation (including nucleation and subsequent growth processes). According to the experimental evidence from temperature-dependent characterization and isolation of the intermediates, the formation of nanobelts undergoes a morphology evolution from nanofibres to nanotubes, and finally to the nanobelts composed of subunit nanoparticles. When used as a cathode for lithium-ion batteries, the as-electrospun Nb-NCM nanobelts exhibit superior electrochemical performances, which could be attributed to their unique features, such as their 1D nanostructure, well-crystallized nature and Nb-doping. These features can improve the ionic conductivity of Nb-NCM nanobelts and stabilize the electrode/electrolyte interface. Therefore, the 1D Nb-NCM nanobelts developed in this study not only provide an excellent model to investigate the fabrication of multi-element oxides using the electrospinning method, but also open up a facile route for designing 1D layered cathodes with a complex component for high performance lithium-ion batteries.
研究领域:
材料科学
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纳米技术
·
电化学
·
能源存储
·
无机合成
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Yingxue Du,Qihao Wang,Xingchao Zang,Weiping Xiao,Yingxia Zong,Xuyun Guo,Zexing Wu,Lei Wang
The development of efficient and durable bifunctional electrocatalysts for overall water splitting remains a key challenge for sustainable hydrogen production. In this study, a novel strategy is proposed to synergistically design boron vacancies and integrate Ru species into NbB 2 (Ru/RuO 2 -NbB 2 -v) by calcination and immersion methods. NbB 2 with its intrinsic high conductivity facilitates to electron transport and improves the reaction kinetics of the catalyst. The strategic introduction of abundant B vacancy and Ru species can expose numerous active sites and lower the reaction energy barriers in the materials, thereby enhancing the reactivity of the catalysts. Impressively, Ru/RuO 2 -NbB 2 -v exhibited superior hydrogen evolution reaction (HER) activity in wide pH range. In addition, Ru/RuO 2 -NbB 2 -v also exhibits good oxygen evolution reaction (OER) performance in acidic and alkaline. A self-assembled electrolyzer driven by simulated solar energy enables the conversion of solar energy into hydrogen energy. The work pioneers a defect-engineering and noble-metal-decoration strategy to transform metal borides into versatile electrocatalysts, offering a scalable pathway for clean energy technologies.
研究领域:
材料科学
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能源技术
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 3
·1143-1150
·
IF 6.641
Zhizhen Wang,Zhen Song,Lixin Ning,Quanlin Liu
Warm-color persistent luminescent materials are strongly desired for signage markings and medical imaging in comparison with green or blue counterparts. Herein we report a novel yellow long-persistent phosphor, Nb-doped Sr3SiO5:Eu2+, with a peak wavelength of ∼580 nm and persistence time of more than 14 hours at the 0.32 mcd m−2 threshold value after UV radiation. A combination of thermoluminescence (TL), thermoluminescence excitation (TLE), electron paramagnetic resonance (EPR) measurements and density functional theory (DFT) calculations reveals that the persistent luminescence enhancement is attributed to a significant Nb-induced increase of oxygen vacancies that act as electron trapping centers with appropriate trap depths. Groups of time-dependent color-change images are realized with this material, which has potential applications as anti-counterfeit and indicator marks. This investigation also expands the application of transition metal (TM) ions to the field of persistent luminescence and would motivate further exploration of TM substitutions to design and improve silicate or aluminosilicate persistent phosphors with superior performance.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2024
·Vol. 26
·期 19
·10168-10176
·
IF 9.3
Weixiang Guan,Chen Cao,Fei Liu,Aiqin Wang,Tao Zhang
Chemocatalytic conversion of cellulose to ethanol provides an alternative route for biofuel production with a theoretical carbon yield of 100%; however, it faces significant challenges of high catalyst cost and poor catalyst stability. In this work, we report a new strategy to decrease the use of expensive noble metals, by decorating mononuclear NbOx on a low-Pt Pt/WOx catalyst surface. The resulting 0.1Nb/0.5Pt/WOx catalyst gave rise to an ethanol yield of 33.7% together with an ethylene glycol yield of 21.8%, and the noble metal efficiency reached 25.90 gethanol gPt−1 h−1, an increase by a factor of 2–10 compared to those in the literature. Moreover, the catalyst stability was significantly enhanced by the decoration of mononuclear NbOx, allowing for recycling at least 7 times without obvious activity decay. Characterization revealed that Pt was highly dispersed at subnanometer and single atom scales, and modification with mononuclear NbOx facilitated hydrogen spillover and created more oxygen vacancies on the WOx surface upon hydrogen reduction, thus generating a higher density of Brønsted acid sites. This effect not only favored cellulose conversion to ethylene glycol but also promoted the hydrogenolysis of ethylene glycol to ethanol.
研究领域:
化学催化
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Linquan Sun,Xukun Zhang,Lina Wang,Hongdong Yu,Fancheng Meng,Tao Qi,Yihe Peng
A fluoride-free solvent extraction method for niobium separation in leached sulfuric mother liquor of ilmenorutile was proposed in this paper. The extraction system comprising trioctyl tertiary amine (N235) and 4-methyl-2-pentanone (MIBK) demonstrated good extraction efficiency and selectivity of niobium over titanium and iron impurities in sulfuric acid–oxalate solutions. Details of extraction, scrubbing, and stripping processes were investigated herein, and its practical effectiveness in both batch and multi-stage simulated counter-current modes was verified. Over 73.8% niobium was extracted under optimum conditions, and only 2.8% titanium and 1.7% iron were co-extracted. The recovery of niobium reached 99.1% in the four-stage simulated counter-current extraction tests. In the three-stage simulated counter-current stripping tests, the stripping efficiency of niobium reached 99.7% with 2.0 mol/L HNO 3 . Qualified niobium oxide products were prepared. The enthalpy change, entropy change, and the standard Gibbs free energy change (Δ H o , Δ S o , and Δ G o , respectively) corroborated the exothermicity, orderliness, and spontaneity of the reaction. The possible composition of the extraction complex was [NbO(C 2 O 4 ) 2 (H 2 O) 2 ] − , as supported by a Fourier transform infrared spectroscopy and ultraviolet–visible spectrophotometry. The extraction mechanism was inferred to be the outer-sphere complexation through physical binding which was the association of R 3 NH + in N235 with the [NbO(C 2 O 4 ) 2 (H 2 O) 2 ] − . A preliminary mass balance indicated that 203.92 g Nb 2 O 5 was generated from 1000 g raw material ilmenorutile.
研究领域:
冶金学
·
化学工程
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 12
·2449
·
IF 4.324
Shiliang Heng,Lei Li,Weiwei Li,Haiyan Li,Jingyu Pang,Mengzhen Zhang,Yan Bai,Dongbin Dang
The development of high-efficiency, recyclable, and inexpensive photocatalysts for water splitting for hydrogen production is of great significance to the application of solar energy. Herein, a series of graphene-decorated polyoxoniobate photocatalysts Nb6/PPy-RGO (Nb6= K7HNb6O19, RGO = reduced graphene oxide, PPy = polypyrrole), with the bridging effect of polypyrrole were prepared through a simple one-step solvothermal method, which is the first example of polyoxoniobate-graphene-based nanocomposites. The as-fabricated photocatalyst showed a photocatalytic H2evolution activity without any co-catalyst. The rate of 1038 µmol g−1in 5 h under optimal condition is almost 43 times higher than that of pure K7HNb6O19·13H2O. The influencing factors for photocatalysts in photocatalytic hydrogen production under simulated sunlight were studied in detail and the feasible mechanism is presented in this paper. These results demonstrate that Nb6O19acts as the main catalyst and electron donor, RGO provides active sites, and PPy acted as an electronic bridge to extend the lifetime of photo-generated carriers, which are crucial factors for photocatalytic H2production.Keywords:polyoxoniobate;Nb6/PPy-RGO composites;electronic bridge;H2production
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Li He,Yingjie Cheng,Qiuju Li,Hainan Zhao,Meiling Wang,Xuejian Shi,Xiaoxin Zou,Yizhan Wang,Yingjin Wei
The shuttling and sluggish conversion kinetics of lithium polysulfides (LPSs) seriously hinder the cycling performance of Li-S batteries. To address this issue, a NbB 2 @CC cathode/separator interlayer is designed by dispersing NbB 2 nanoparticles in a textile carbon cloth (CC). NbB 2 has stronger adsorption ability than CC, which can effectively capture the dissolved LPSs in the electrolyte. Then, under the catalysis of NbB 2 , the reaction kinetics of LPSs is greatly facilitated. Benefiting from these advantages, the Li-S cell can offer a high discharge capacity of 735.2 mA·h·g −1 at 1C, with very small capacity fading in 800 cycles. It also shows excellent low-temperature performance, which can deliver a stable discharge capacity of 802 mA·h·g −1 at −10 °C. Moreover, a high areal capacity of 7.34 mA·h·cm −2 is achieved for the Li-S cell with a high sulfur loading of 9.45 mg·cm −2 and low electrolyte/sulfur ratio of 6.34 µL·mg −1 .
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 32
·27094-27101
·
IF 3.289
Xiao Yu,Ling Xin,Yong Liu,Wenxia Zhao,Baojun Li,Xiang Zhou,Hui Shen
One of the main drawbacks with applying the most promising electrode materials in lithium-ion batteries is their intrinsic poor electronic conductivity. Many approaches which include mixing them with good electrical conductors have been developed to solve this problem, yet they do not improve the lattice electronic conductivity within the crystal. Here we present a one-step hydrothermal route for fabricating the core–shell heterostructures through sequential growth of the core and shell materials. The cores are Nb-doped TiO2 rods with improved conductivity that can deliver high capacity, yet the Nb2O5 nanosheets shells can act as a protective layer to prevent electrode dissolution and maintain the electrode integrity over long term cycles and contribute additional lithium storage capacity. When employed as an anode material in lithium-ion batteries, it exhibits an outstanding cycle stability of 189 mA h g−1 at 170 mA g−1 for more than 700 cycles. This work provides an important strategy to improve the conductivity of the host and construct a protective layer by simply adding a guest ion in reaction.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机化学
·
固态化学
·
电池技术
✓ 已验证
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2020
·Vol. 23
·期 1
·2000691
·
IF 3.217
Lu Zhu,Xuanru Ren,Xueqin Kang,Ping Zhang,Peizhong Feng,Xiaohong Wang
MoSi 2 coatings are prepared using spent and commercial MoSi 2 powders as raw materials to protect niobium (Nb) substrate by spark plasma sintering (SPS) technique, and the microstructure and oxidation resistance of the coatings at 1500 °C are investigated. Results showed that obvious pores are found in MoSi 2 coating using commercial MoSi 2 (MC coating) after SPS while MoSi 2 coating using spent MoSi 2 (MS coating) is dense with low porosity. (Mo,Nb) 5 Si 3 diffusion layer is generated between MS coating and the substrate with no gap or cracks, showing excellent metallurgical bonding. After long-term oxidation at elevated temperature, pores and exposed Mo 5 Si 3 can be observed in the oxide scale of MC coating, while dense and complete oxide scale is obtained by MS coating. Lowest mass gain (2.78 mg cm −2 ) is acquired by MS coating after oxidation at 1500 °C for 40 h because SiO 2 oxide scale is completely formed on the dense and bentonite-containing coating, blocking the diffusion of oxygen at high temperature. Compared with MC coating, no further oxidation occurs inside the MS coating or substrate, exhibiting better high-temperature oxidation resistance.
研究领域:
材料科学
·
表面工程
✓ 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）