ENERGY & FUELS
·
2024
·
IF 5.2
Xin Zhang,Zaiman Zhang,Hao Li
The aqueous hydrodeoxygenation (HDO) of renewable biomass is an effective method to produce alternative fuels and high-value-added chemicals. Nonetheless, metal leaching and support collapse are the main obstacles in aqueous HDO. Herein, a series of Ni/T-Nb2O5@C catalysts were successfully prepared for selective HDO of vanillin (a typical lignin-derived model compound). Characterization results revealed that the superior catalytic performance of Ni/T-Nb2O5@C catalysts was due to the efficient adsorption of the reactant preferentially via oxygen vacancies and the excellent selection of deoxygenated products via acid sites on the catalyst surface. Meanwhile, water can interact with vanillyl alcohol (VA) through hydrogen bonding to form a more stable transition state, further reducing the activation energy of the VA hydrogenolysis process and promoting the conversion of VA to 2-methoxy-4-methylphenol (MMP). Ni/T-Nb2O5@C2-2 catalyst exhibited excellent performance for vanillin HDO, achieving 99.9% conversion, 96.6% MMP selectivity, and 87.7% mass yield at 150 °C for 1 h, 1 MPa H2, and a water:ethanol ratio of 8:12, which greatly improved the MMP selectivity (79.2%) of unmodified Ni/T-Nb2O5 catalyst. Moreover, the catalyst had good catalytic capability after eight cycles of less than 25% conversion, and the retention of the initial active substance during the reaction was analyzed. This work may provide insights into the rational design of composite-supported catalysts for biomass-derived compounds HDO in the aqueous phase.
研究领域:
催化化学
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生物质能
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材料科学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Wanxing Zhang,Pengcheng Mao,Yuhang Jin,Hai Ming,Zhipeng Li,Danfeng He,Hongyu Sun,Yanlong Yu,Yanguo Liu
Niobium pentoxide (Nb 2 O 5 ) anodes have attracted much attention as a candidate for the next generation lithium-ion batteries (LIBs) due to the unique physical and chemical properties. However, some critical issues, like low electronic conductivity, inefficient ionic diffusion, must be addressed before practical applications. In this work, we employed a facile NaBH 4 engaged chemical reduction method to modify Nb 2 O 5 anodes. Microstructure and surface chemistry analysis indicated that the Nb 2 O 5 materials have micro/nanoscale three-dimensionally interconnected morphology, and contain three different phases (T-, M-, and H-Nb 2 O 5 ). More importantly, oxygen vacancies are introduced by the NaBH 4 reduction treatment, and the oxygen vacancy amount can be modulated by changing the NaBH 4 concentration. As anodes for LIBs, the optimized sample exhibited a reversible capacity of 252.2 mAh·g −1 after 100 cycles at a current density of 1 C, and a reversible capacity of 139.4 mAh·g −1 at a large current density of 10 C. The electrochemical performance enhancement can be attributed to the combination of multiscale structural design, i.e., oxygen vacancy, nanoscale phase interface , and micro/nanoscale three-dimension assembly. We expect the present synergistic strategy can be employed to manipulate the key structures in different functional materials for broader applications.
研究领域:
材料科学
·
能源存储
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Qi Lai,Yu Dou,Qing Zhang,Yunhai Zhu,Yingkui Yang
Orthorhombic Nb 2 O 5 (T-Nb 2 O 5 ) has emerged as a promising fast-charging anode due to its open framework structure, safe potential and intercalation pseudocapacitance characteristic. However, its practical application is hindered by the low electronic conductivity. Herein, a synergistic nano-amorphization engineering strategy was employed to fabricate crystalline-amorphous core-shell T-Nb 2 O 5 (C/A-T-Nb 2 O 5 ) nanofibers via electrospinning technology. The obtained carbon-free, chain-like C/A-T-Nb 2 O 5 nanofibers formed via interconnected Nb 2 O 5 nanoparticles enables rapid kinetics and excellent structural stability without compromising the energy density. The chemical etching creates an amorphous shell on single-crystalline core, which establishes a built-in electric field (BIEF) at the interface. In-situ characterizations with theoretical simulations suggest that BIEF effectively drives electrons from amorphous shell to the inner reaction sites and lowers Li-ions diffusion barrier. The amorphous shell with oxygen vacancies boosts Li-ions/electron transport, simultaneously alleviating lattice stress during cycling. Consequently, C/A-T-Nb 2 O 5 delivers a superior rate capability of 102 mAh g −1 at 50C and exceptional durability, retaining 69.5% capacity after 2000 cycles at 10C. A full pouch cell paired with C/A-T-Nb 2 O 5 anode and NCM811 cathode further demonstrates the practical viability. This integrated architectural modulation and amorphization engineering strategy establish a new paradigm for designing kinetically balanced electrodes for high-power batteries.
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DOI
高影响因子
SOLAR ENERGY
·
2017
·
IF 4.018
Liang Chu,Wei Liu,Aiai Yu,Zhengfei Qin,Ruiyuan Hu,Huazhong Shu,Qiu-Ping Luo,Yonggang Min,Jianping Yang,Xing'ao Li
TiO 2 modification via TiCl 4 treatment has been widely used to improve the power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs), in which the effects usually attribute to the inhibition of charge recombination by barrier effect. Niobium pentoxide (Nb 2 O 5 ) is considered a promising photoelectrode material for DSSCs. Here we prepared urchin-like orthorhombic Nb 2 O 5 nanospheres consisting of ultrathin nanorods by a hydrothermal method , which were further developed as photoelectrodes for DSSCs. The TiO 2 modification on the urchin-like orthorhombic Nb 2 O 5 nanospheres increases the photocurrent and PCE of the DSSCs. However, the impedance spectroscopy showed that charge recombination was not reduced by the TiO 2 modification. The improvement in the photocurrent and PCE has been attributed to the enhanced absorption of dye molecules (N719). The results indicate that the enhancement of dye absorption for orthorhombic Nb 2 O 5 photoelectrodes is the desirable approach to improve the performance of orthorhombic Nb 2 O 5 -based DSSCs.
研究领域:
材料科学
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能源科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Dongsheng Jiang,Yuzhe Li,Chao Zhang,Ruifang Wang,Jinpeng Zhu,Wen Chen,Yusi Che,Jilin He
Bayan Obo tailings are rich in niobium and other valuable elements; however, the phase evolution of niobium-bearing slag within these tailings remains poorly understood. This knowledge gap significantly impedes comprehensive utilization of these strategic resources. In this study, a CaO-SiO 2 -Nb 2 O 5 -5%Na 2 O-5%Al 2 O 3 -3%CaF 2 slag system was investigated to examine the phase equilibrium types, compositional characteristics, and distributional evolution under varying w (CaO)/ w (SiO 2 ) ratios and w (Nb 2 O 5 ) contents, using high-temperature equilibrium experiments. Following a 24-hour high-temperature equilibrium treatment at 1473 K under an argon atmosphere, a range of compounds including 13CaO·8SiO 2 ·Nb 2 O 5 ·CaF 2 , 2CaO·4SiO 2 ·Na 2 O·Al 2 O 3 , CaO·Nb 2 O 5 ·NaF, 2CaO·Nb 2 O 5 , and CaO·SiO 2 were identified. An increase in Nb 2 O 5 content coupled with a reduction in the w (CaO)/ w (SiO 2 ) ratio favored the formation of CaO·Nb 2 O 5 ·NaF (pyrochlore phase) and 2CaO·Nb 2 O 5 . These two phases exhibited high Nb concentrations, with the CaO·Nb 2 O 5 ·NaF (pyrochlore) phase containing up to approximately 70% Nb. The optimal smelting conditions for niobium enrichment in the pyrochlore phase were identified within the range of w (CaO)/ w (SiO 2 ) = 0.74∼0.80 and w (Nb 2 O 5 ) = 13.61%∼16.11%.
研究领域:
冶金学
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材料科学
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矿物加工
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物理化学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Wenkang Xu,Xiaoyao Li,Chao Peng,Guangxing Yang,Yonghai Cao,Hongjuan Wang,Feng Peng,Hao Yu
MXenes, 2D transition metal carbides/nitrides, have been demonstrated as promising platform for fabricating novel composites with interesting photo-/electrochemical properties. It is desirable to gain insights into the reactivity of MXenes, enabling the controllable transformation of MXenes. Here, a one-pot hydrothermal synthesis method of MXene-based photocatalyst is validated by harnessing the reducibility of Nb 2 CT x MXene . The origin of reducibility of Nb 2 CT x during the hydrothermal oxidation process was demonstrated as the active hydrogen produced from the water splitting in the presence of Nb 2 CT x , which reduced Ru 3+ in situ to Ru nanoparticles on Nb 2 O 5 nanowires derived from Nb 2 CT x . Compared with the traditional photo-deposition method, the chemical valance of the noble metal Ru/Pt obtained by the one-pot synthesis method was closer to the metal state, which reduced the charge transfer resistance by 82.5%. It led to the photocatalytic hydrogen production of 10.11 mmol·h −1 ·g −1 with 41.25% apparent quantum yield at 313 nm.
研究领域:
材料科学
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光催化
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能量转换
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纳米材料
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氢气生产
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DOI
高影响因子
MATERIALS & DESIGN
·
2017
·
IF 4.364
Puhong Wen,Lili Ai,Taotao Liu,Dengwei Hu,Fangyi Yao
The regular orthorhombic Nb 2 O 5 (O-Nb 2 O 5 ) rectangle nanosheets dominantly exposed (010) facet are synthesized by a hydrothermal topological reaction with a precursor of K 4 Nb 6 O 17 ·4.5H 2 O (KNbO). The structure and morphology of the samples obtained at different temperatures and pH values of reacting solution are investigated. The results suggest that there are two topological reactions in this process. One is the acid-exchanging reaction transforming into H 4 Nb 6 O 17 ·3H 2 O (HNbO) nanosheets from KNbO rectangle nanosheets , and the other is dehydration reaction transforming into O-Nb 2 O 5 rectangle nanosheets from HNbO nanosheets. And the {010} facets of O-Nb 2 O 5 crystal are transformed from the {010} facets of HNbO crystal in the ingenious topological reaction. The photoelectric performance of the obtained O-Nb 2 O 5 nanosheets is evaluated by decomposing water to H 2 under 370 nm UV light illumination and measuring the accompanying photocurrent . The photocurrent density is 680 nA·cm − 2 generated by splitting water with O-Nb 2 O 5 nanosheets as photocatalyst , and it is 4.3 times of the contrast sample. The result indicates that the (010) facet of O-Nb 2 O 5 is one of the highest photocatalytic active surfaces and shows high photoelectric conversion efficiency. Thus, the O-Nb 2 O 5 nanosheets dominantly exposed (010) facet have potential applications in photocatalyst and photoelectric nanodevices .
研究领域:
材料科学
·
光催化
·
纳米材料
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无机化学
·
能源材料
✓ 已验证
DOI
高影响因子
DESALINATION
·
2026
·
IF 9.9
Markos Medhin Ashebo,Zixiao Xu,Haolan Shi,Huancheng Dong,Ningning Liu,Fei Yu,Jie Ma
1D Nb 2 O 5 nanorods grown in situ uniformly on the surface 2D Nb 2 C MXene. • Nb 2 O 5 nanorods act as passivation layers, mitigating MXene restacking and oxidation. • Interfacial charge transfer between Nb 2 O 5 and Nb 2 C accelerates electron kinetics. • The Nb 2 O 5 -Nb 2 C hybrid exhibits excellent desalination performance and cycling stability. Self-stacking and oxidative instability limit the ion accessibility and cycling stability of MXene electrodes in capacitive deionization (CDI). To address these limitations, a controlled partial derivation strategy was used to construct Nb 2 O 5 nanorods on Nb 2 CT x MXene nanosheets, forming 1D Nb 2 O 5 nanorod/2D Nb 2 C heterostructure. The derived Nb 2 O 5 nanorods increased the accessible surface area, provided expanded ion intercalation channels, suppressed Nb 2 CT x restacking, and also acted as a partial passivation layer to inhibit further MXene oxidation. Electrochemical measurements showed that the Nb 2 O 5 -Nb 2 C electrode exhibited higher capacitance and lower charge-transfer resistance than pristine Nb 2 C, suggesting improved interfacial charge transfer behavior and ion storage kinetics. The Nb 2 O 5 -Nb 2 C hybrid delivered a salt adsorption capacity (SAC) of 51.2 mg g −1 at 1.6 V, an average salt removal rate (SAR) of 1.7 mg g −1 min −1 , and retained 90.5% of its initial capacity after 200 cycles. These results indicate that controlled partial oxidation can not only mitigates the instability of Nb 2 C, but also improves ion accessibility, electrochemical kinetics, and cycling durability of Nb-based MXene electrodes for CDI. Download: Download high-res image (360KB) Download: Download full-size image
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DOI
高影响因子
RARE METALS
·
2020
·Vol. 40
·期 2
·374-382
·
IF 2.161
He Si-Ru,Zou Jian-Peng,Chen Li-Bao,Chen Yue-Jiao
Abstract In this work, nickel/T-Nb 2 O 5 nanoparticles encapsulated in mesoporous carbon nanofibers (denoted as Ni/T-Nb 2 O 5 @CNFs) are successfully prepared through a simple electrospinning route and succedent heating treatment. The presence of Ni in carbon nanofibers is beneficial for enhancing the electronic conductivity and the initial Coulombic efficiency. Ni/T-Nb 2 O 5 nanoparticles are homogeneously incorporated in carbon nanofibers to form a nanocomposite system, which provides effective buffering during the lithiation/delithiation process for cycling stability. The Ni/T-Nb 2 O 5 @CNFs show high surface area (26.321 m 2 ·g −1 ) and mesoporous microstructure, resulting in higher capacity and excellent rate performance. The Ni/T-Nb 2 O 5 @CNFs exhibit a remarkable capacity of 437 mAh·g −1 at a current density of 0.5 A·g −1 after 230 cycles and a capacity of 173 mAh·g −1 at a current density up to 10.0 A·g −1 after 1400 cycles. This work indicates that nickel/T-Nb 2 O 5 nanoparticles encapsulated in carbon nanofibers can be a promising candidate for anode material in high-power LIBs. Graphic abstract
研究领域:
材料科学
·
能源存储
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产品关联
DOI
高影响因子
Green Energy & Environment
·
2019
·
IF 0
Xiaolan Deng,Yuqi Jiang,Zengxi Wei,Minglei Mao,Ramyakrishna Pothu,Hongxia Wang,Caiyun Wang,Jinping Liu,Jianmin Ma
Increasing the energy density, power density as well as widening the operation voltage are essential to electrochemical capacitors to meet the practical energy demands. Herein, a novel flexible quasi-solid-state dual-ion asymmetric supercapacitor (ASC) with Ni(OH) 2 and Nb 2 O 5 nanosheets directly grown on stainless steel mesh is developed. In the dual-ion ASC, Nb 2 O 5 negative and Ni(OH) 2 positive electrodes react with Li + and OH − respectively in alkaline gel electrolyte to store energy, which is quite different from conventional alkali metal ion SCs and alkaline SCs. The as-assembled flexible device has an extended working voltage of 1.7 V and delivers a capacity of 5.37 mAh cm −2 , a maximum energy density and power density of 0.52 mWh cm −3 and 170 mW cm −3 , respectively. The device maintains around 60% capacity retention after long cycling up to 1000 cycles. Moreover, our device can light up a LED light efficiently upon fast charging. The proposed quasi-solid-state dual-ion ASC has potential applications in future portable electronics and flexible energy storage devices.
研究领域:
材料科学
·
能源存储技术
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产品关联
DOI
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Wan-Jing Yu,Zhiyuan Liu,Qiongyu Dai,Maria A. Tsiamtsouri,Tianhui An,Hui Tong
Niobium-oxide based materials are well-known in electrochemical energy area because of their unique structural advantage, which can realize fast ion insertion/extraction and interfacial pseudo-capacitance effects. However, instinct poor electrical conductivity and terrible volume change of Nb 2 O 5 under lithiation/delithiation have hindered its practical application. Here, a three-dimensional (3D) graphene network has been constructed by a simple hydrothermal reaction and utilized to buffer the severe structural variation of Nb 2 O 5 . Meanwhile, silver nanoparticles have been incorporated into this 3D structure through silver-mirror reaction, by which the charge-transfer ability of the composite (Ag-Nb 2 O 5 @rGO) can be significantly improved. The obtained Ag-Nb 2 O 5 @rGO can contribute a charge capacity of ∼ 208.0 mAh/g at 0.5C and ∼ 106.6 mAh/g up to 20C. Meanwhile, superior cyclic performance with ∼ 80 % capacity retention after 500 cycles at 2.5C can be achieved. This demonstrates that the Ag-Nb 2 O 5 @rGO composite can work as a high-performance anode for electrochemical energy devices.
研究领域:
材料科学
·
能源存储
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产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2022
·Vol. 34
·期 16
·2200756
·
IF 32.086
Xi Lin,Shuhui Xia,Liang Zhang,Yuanyuan Zhang,Songmei Sun,Yuehui Chen,Shuo Chen,Bin Ding,Jianyong Yu,Jianhua Yan
Achieving high selectivity and conversion efficiency simultaneously is a challenge for visible-light-driven photocatalytic CO 2 reduction into CH 4 . Here, a facile nanofiber synthesis method and a new defect control strategy at room-temperature are reported for the fabrication of flexible mesoporous black Nb 2 O 5 nanofiber catalysts that contain abundant oxygen-vacancies and unsaturated Nb dual-sites, which are efficient towards photocatalytic production of CH 4 . The oxygen-vacancy decreases the bandgap width of Nb 2 O 5 from 3.01–2.25 eV, which broadens the light-absorption range from ultraviolet to visible-light, and the dual sites in the mesopores can easily adsorb CO 2 , so that the intermediate product of CO* can be spontaneously changed into *CHO. The formation of a highly stable Nb CHO* intermediate at the dual sites is proposed to be the key feature determining selectivity. The preliminary results show that without using sacrificial agents and photosensitizers, the nanofiber catalyst achieves 64.8% selectivity for CH 4 production with a high evolution rate of 19.5 µmol g −1 h −1 under visible-light. Furthermore, the flexible catalyst film can be directly used in devices, showing appealing and broadly commercial applications.
研究领域:
材料科学
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环境科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）