APPLIED CATALYSIS B-ENVIRONMENTAL
·
2016
·
IF 8.328
Jing Guo,Shanhui Zhu,Youliang Cen,Zhangfeng Qin,Jianguo Wang,Weibin Fan
A series of ordered mesoporous Nb x W (8 − x) oxides with tunable Nb/W ratio were successfully synthesized by evaporation-induced self-assembly method. The mesoporous structure, morphologies, surface chemical state, and acidic properties of these catalysts were fully characterized by low-temperature sorption of N 2 , small-angle and wide-angle XRD, TEM, Raman, XPS, and Py-IR. It was shown that the Nb x W (8 − x) oxides created large amounts of Lewis as well as Brønsted acid sites, which promoted the isomerization of glucose to fructose followed its dehydration to 5-hydroxymethylfurfural (HMF). Mannose was also formed via the epimerization of glucose. Of them, the mesoporous Nb 4 W 4 exhibited the best catalytic activity with a comparatively low E a about 90.2 kJ/mol and good stability in aqueous medium. The kinetic behavior revealed that Lewis acid sites facilitated to glucose-to-fructose isomerization while Brønsted acid sites promoted the dehydration of fructose to form HMF.
研究领域:
催化化学
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生物质转化
·
绿色化学
·
多相催化
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材料化学
·
碳水化合物化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 58
·期 2
·707-717
·
IF 4.5
Sui Yudong,Yuan Yanru,Tan Pan,Jiang Yehua,Han Lina
This paper presents the experimental investigation of the effect of Nb 2 O 5 content on the phase composition, microstructure, and physical and mechanical performance of the zirconia-toughened alumina (ZTA) ceramics, aimed to optimize the additional amount of Nb 2 O 5 , refine the ceramic grains, and improve the densification, hardness and fracture toughness. ZTA ceramics with various Nb 2 O 5 contents were prepared using the spark plasma sintering method. The addition of trace amounts of Nb 2 O 5 did not produce a new Nb-rich phase; the Nb atoms were dissolved in the ZrO 2 grains. The addition of trace amounts of Nb 2 O 5 led to grain refinement and an increase in density, but the addition of excessive Nb 2 O 5 resulted in grain growth and a decrease in relative density. Furthermore, the addition of Nb 2 O 5 promoted uniformity of the microstructure. The sample with 0.25 wt.% Nb 2 O 5 had the maximum Vickers hardness and indentation fracture toughness, which were 1228.40 HV and 9.17 MPa √m, respectively. Mechanical properties of the composite mainly depended on the grain size, which was influenced to some extent by the relative density.
研究领域:
材料科学
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无机非金属材料
·
陶瓷学
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结构陶瓷
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粉末冶金
✓ 已验证
DOI
高影响因子
Solar RRL
·
2023
·Vol. 7
·期 13
·2300185
·
IF 7.9
Boyang Han,Yanping Song,Huanhuan Sun,Junjie Ma,Rensheng Wang,Xinlong Fan,Dan Chi,Xiuqing Meng,Shihua Huang,Bin Yao
As compared to the predecessor Cu(In,Ga)Se 2 device, the current efficiency of kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells is still much lower mainly due to the known carriers recombination issue within interface and absorber bulk. In contrast to the majority of researches concerning recombination issues that focus on either single absorber bulk or interface passivation strategy, this study is pioneering in constructing synergistic passivation effects (SPE) to address the bulk and interface recombination issue simultaneously. By introducing a novel niobium pentoxide passivation layer into the back electrode interface (BEI), it is identified that SPE can be constructed due to Nb (& O) diffusion from Nb 2 O 5 layer to absorber bulk and BEI during high-temperature selenization. The chemical passivation effect is fulfilled via the intrinsic high resistance characteristic of Nb 2 O 5 layer, and also through the NbO x passivation aiming to absorber bulk benefited from Nb (& O) diffusion. Meanwhile, the occupations of Nb (& O) on the Mo (& Se) sites induce a conduction type inversion in MoSe 2 interfacial layer and create a preferable interface p + -Mo(Se,O) 2 :Nb/CZTSSe, achieving an interfacial field passivation effect. Ultimately, the promoted absorber quality and improved charge carrier transportation from SPE contribute to the boost of device performance beyond 10% efficiency.
研究领域:
材料科学
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可再生能源
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太阳能电池技术
·
半导体物理
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Peng Hei,Shanshan Luo,Kuo Wei,Junshuang Zhou,Yufeng Zhao,Faming Gao
For the past few years, intercalation-type niobium-based oxides have attracted tremendous attention due to their excellent electrochemical performance, but their rate performance and stability still need to be improved. Here, we synthesized P4Nb2O15 by a simple solvothermal method, used it as anode material in lithium-ion batteries for the first time, and further prepared P4Nb2O15@CNTs on the basis of previous research. The results indicated that P4Nb2O15@CNTs delivered a high reversible lithium storage capacity (563.3 mAh g–1 at 0.1C), with excellent rate performance (115.9 mAh g–1 at a high rate of 50C) and outstanding cycle performance of 0.0178% of capacity lost per cycle after 500 cycles at 10C. Moreover, it showed a significant interlayer pseudocapacitive contribution of 88.5% at 1.0 mV s–1. All of these advantages indicate that P4Nb2O15@CNTs have a wide application prospect as anode material in lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米复合材料
·
锂离子电池
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 46
·26513-26523
·
IF 10.733
Peng Huang,Min Huang,Hai Hu,Yuan Zhong,Chao Lai,Shulei Chou
The push for high performing electronic devices with long battery lives has rapidly advanced the field of energy storage systems. Niobium oxides have stood out as promising candidates to improve the storage and rate performance of anodes in lithium- and especially sodium-ion batteries due to their larger interplanar lattice spacing and patulous framework. Herein, we report the first synthesis of a nanosized metal/metal oxide hybrid composite coated by N-doped carbon and anchored onto reduced graphene oxide (NbO/Cu@NC-RGO) through in situ carbonizing of Cu-doped polyoxoniobate precursors. The strong synergistic effects between the uniformly distributed NbO/Cu hybrid nanoparticles, the N-doped carbon coating layer, and graphene substrates not only ensure efficient electron and ion transport, but also boost pseudocapacitive charge storage. The resulting composite exhibits a maximum reversible charge capacity of 580 mA h g−1 after 100 cycles at a current density of 100 mA g−1 when utilized in lithium-ion batteries (LIBs), and 203 mA h g−1 when utilized in sodium-ion batteries (SIBs). For SIBs in particular, a long-lifetime of 1012 cycles is observed when cycled at a high current density of 800 mA g−1. This work represents a promising step forward in the design and preparation of metal oxide composite anodes for LIBs and SIBs.
研究领域:
材料科学
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电化学
·
纳米能源
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储能技术
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无机化学
·
先进电池材料
✓ 已验证
DOI
高影响因子
RARE METALS
·
2020
·Vol. 40
·期 2
·425-432
·
IF 2.161
Huang Min,Liu Ji-Xin,Huang Peng,Hu Hai,Lai Chao
A two-dimensional (2D) SnNb 2 O 6 /amino-functionalized graphene (En-RGO) nanocomposite with a representative 2D–2D architecture has been constructed by an easy self-assembly approach and firstly investigated as anode materials for secondary sodium-ion batteries. The SnNb 2 O 6 nanosheets are evenly anchored with the amino-functionalized graphene through electrostatic attractive interplay between the negatively charged SnNb 2 O 6 and positively charged En-RGO after modification. As a result, a remarkable reversible capacity of 300 mAh·g −1 was obtained at 50 mA·g −1 , and significantly, the En-RGO electrode could also deliver ultra-long calendar life up to 1900 cycles with a high reversible capacity of 200 mAh·g −1 at current of 500 mA·g −1 . Such excellent electrochemical characteristics can be mainly ascribed to its fast pseudo-capacitive energy storage mechanism, and the capacitive contribution can even reach up to 90% at 1.2 mV·s −1 . Graphic abstract
研究领域:
材料科学
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电化学
·
纳米科技
·
能源存储
·
无机化学
·
功能材料
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电化学储能
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2024
·Vol. 154
·期 7
·3426-3440
·
IF 2.3
Han Qi,Shi Yong,Han Yuchan,Chen Rui,Hou Yuelei,Li Jun
A series of niobium-based catalysts with carboxylated multi-walled carbon nanotube (C-CNT) as support were prepared by modified wet-chemical technique under ultrasonication. Three types of catalysts with active component niobium attached only on the inner or outer walls respectively, or mainly on the outer walls were obtained by adjusting the impregnation strategies. The catalysts were characterized systematically by SEM, TEM, XRD, Raman, FT-IR, XPS, and N 2 adsorption–desorption. It was found that niobia species was highly dispersed on the outer wall or the channels of C-CNT. There are abundant oxygen-containing groups on the catalysts. Strong chemical interactions between the support and Nb 2 O 5 are evident. The catalytic performances of the C-CNT-supported catalysts were evaluated for the selective oxidation of cyclopentene (CPE) to glutaraldehyde (GA) with 30 wt% aqueous H 2 O 2 as oxidant. The conversion of CPE and the selectivity to GA reached 98.3% and 59.3% respectively under the optimized conditions. No significant deterioration of the catalytic performance was found in the catalyst-cycling experiments, indicating the stability of the catalyst. Hot filtration experiments revealed that the catalytic reaction was heterogeneous. The good performance of the catalyst in ethanol makes the catalytic system of an excellent application prospect. Graphical
研究领域:
催化化学
·
材料科学
·
化学工程
·
纳米技术
·
有机化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2015
·
IF 2.002
Lei Chen,Zhichun Si,Xiaodong Wu,Duan Weng,Zhenwei Wu
A MnO x –NbO x –CeO 2 catalyst for low temperature selective catalytic reduction (SCR) of NO x with NH 3 was prepared by a sol–gel method, and characterized by NH 3 –NO/NO 2 SCR catalytic activity , NO/NH 3 oxidation activity, NO x /NH 3 TPD , XRD , BET, H 2 -TPR and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The results indicate that the MnO x –NbO x –CeO 2 catalyst shows excellent low temperature NH 3 -SCR activity in the temperature range of 150–300°C. Water vapor inhibits the low temperature activity of the catalyst in standard SCR due to the inhibition of NO x adsorption. As the NO 2 content increases in the feed, water vapor does not affect the activity in NO 2 SCR. Meanwhile, water vapor significantly enhances the N 2 selectivity of the fresh and the aged catalysts due to its inhibition of the decomposition of NH 4 NO 3 into N 2 O.
研究领域:
环境催化
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大气污染控制
·
材料化学
·
表面科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 8
·4880-4889
·
IF 12.732
Wei Wu,Wang Lin,Hongjiang Chen,Keyan Wei,Zhitong Li,Haitao Yang,Mingxian Liu,Huaicheng Xiang,Libo Deng,Lei Yao
The development of high-performance solid-state batteries (SSBs) that integrate high safety with high energy density has long been pursued. However, conventional lithium-containing anode materials are unable to balance these two requirements, thereby necessitating the exploration of lithium-free anodes for SSBs. In the current study, a core–shell lithium-free α-Fe2O3@TiNb2O7 (TNO) nanofiber composite is synthesized and applied as an SSB anode. The confinement effect from the hollow TNO nanotubes on the encapsulated α-Fe2O3 nanoparticles can buffer the volume-change crushing during charging/discharging, leading to robust structural stability. Moreover, the high rate capability of TNO and high capacity of α-Fe2O3 work synergistically to provide superior electrochemical performances. The prepared α-Fe2O3@TNO composite delivers twice the reversible capacity (625 mA h g−1 at 0.1 A g−1) of pristine TNO as well as a remarkably prolonged cycle life (500 cycles with 79.2% capacity retention) and an improved rate performance (305 mA h g−1 at 3 A g−1) compared with those of α-Fe2O3, making this composite the most efficient TNO-based anode material ever reported. By pairing the composite with the high-energy Li[Ni0.8Co0.1Mn0.1]O2 (NCM811) cathode, the SSB full cell exhibits a high energy density of 400 W h kg−1. These results demonstrate the feasibility and great potential of the proposed lithium-free anode material in SSBs for practical applications.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Jingbin Wei,Hongshuo Cao,Yanhong Tian,Xuejun Zhang
To address the inherently poor electronic and ionic conductivity of titanium-niobium oxide materials and to improve their suitability for use at high current densities , we designed and synthesized Ti 2 Nb 10 O 29 (TNO) microspheres with diameters of 1 to 3 μm by a simple solvothermal method . Then, MXene, a highly conductive two-dimensional material, was introduced and perfectly coated onto the microsphere surface by electrostatic forces and chemical bonding. The MXene nanosheets not only improve the overall conductivity but also protect the TNO microspheres and reduce the electrochemical polarization at high current densities. Thus, the composite anode electrode shows outstanding reversible specific capacity and stability at high currents and long cycles. Specifically, at 20 C, the initial reversible specific capacity of the TNO@MXene electrode was 200.3 mAh.g −1 with a coulomb efficiency of 94.4%. The reversible specific capacity remained at 131.2 mAh.g −1 even after 1400 cycles with an average capacity loss rate of only 0.02%. In addition, the outstanding pseudo-capacitance property of TNO@MXene ensures its fast charging and discharging capability and capacity at a high rate.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Wellars Utetiwabo,Muhammad Khurram Tufail,Chaoyuan Zeng,Lei Zhou,Le Yang,Ze Hua,Jinfeng Zeng,Peiwen Yu,Ruiwen Shao,Wen Yang
The induction of cation dopant into the lattice structure of anode materials is a feasible and effective method to modulate the electronic structure and induce different active sites for Li + storage. However, it is a challenge to create the cation dopant into the structure of the transition metal oxides anode of the lithium-ion batteries (LIBs). In this work, we propose an in-situ source template thermal reduction of graphite foam (GF) and annealing process for the first time to successfully induce Ti 3+ into the titanium niobium oxide (Ti 2 Nb 10 O 29 , TNO) nanocrystal structure denoted as TNO@GF for high-energy/power lithium storage. The induction of Ti 3+ could not only prompt the more active sites for Li + ion storage but also modulate the electronic interaction between the active sites and the intercalated Li + ion, leading to the favorable Li + ions intercalation and minimizing the Li + -ion diffusion barriers in the open channel of the ReO 3- type structure unit. Due to the combined effect of nanocrystal structure and Ti 3+ , TNO@GF yields a higher reversible discharge capacity of 328 mAh g −1 at 0.1C, a higher rate capability of 296.3 mAh g −1 ; and keeps 207.88 mAh g −1 at a high rate of 35 C and shows good cycling stability (217.73 mAh g −1 at the rate of 10 C) with the capacity retention of 83.20 % after 500 cycles. These findings provide insights into cation engineering and its influence on the functional nanomaterials' physicochemical properties, which are not achievable in the perfect crystal for advanced energy storage applications.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米技术
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2022
·Vol. 15
·期 16
·e202200827
·
IF 9.14
Qimin Peng,Xiaoling Zhuang,Longgui Wei,Luyan Shi,Tayirjan Taylor Isimjan,Ruobing Hou,Xiulin Yang
Graphical A thorny challenge : A nanothorn-like superhydrophilic Nb−CoSe 2 /CC (CC=carbon cloth) catalyst is fabricated through a facile in-situ hydrothermal selenization and Ar annealing strategies. The catalyst illustrates an excellent oxygen evolution activity (297 mV at 200 mA cm −2 ), outstanding long-term durability, and good overall water splitting performance (1.93 V at 500 mA cm −2 ). Developing cost-effective, highly active, and robust electrocatalysts for oxygen evolution reaction (OER) at high current density is a critical challenge in water electrolysis since the sluggish kinetics of the OER significantly impedes the energy conversion efficiency of overall water splitting. Here, a 1D nanothorn-like Nb−CoSe 2 /CC (CC=carbon cloth) structure was developed as an efficient OER catalyst. The optimized Nb−CoSe 2 /CC catalyst exhibited remarkable OER performance with the low overpotentials of 220 mV at 10 mA cm −2 and 297 mV 200 mA cm −2 and a small Tafel slope (54.1 mV dec −1 ) in 1.0 m KOH electrolyte. More importantly, the Nb−CoSe 2 /CC electrode displayed superior stability after 60 h of continuous operation. In addition, cell voltages of 1.52 and 1.93 V were required to achieve 10 and 500 mA cm −2 for the electrolyzer made of Nb−CoSe 2 /CC (anode) and the Pt/C (cathode). Density functional theory (DFT) calculations combined with experimental results revealed that incorporating niobium into the CoSe 2 could optimize the adsorption free energy of the reaction intermediates and enhance the conductivity to improve the catalytic activity further. Additionally, the super-hydrophilicity of Nb−CoSe 2 /CC resulting from the surface defects increased the surface wettability and facilitated reaction kinetics. These results indicate that Nb−CoSe 2 /CC intrinsically enhances OER performance and possesses potential practical water electrolysis applications.
研究领域:
电化学
·
材料科学
·
催化
·
能量转换
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）