ChemElectroChem
·
2018
·Vol. 5
·期 17
·2464-2474
·
IF 4.446
Zhangxing He,Yingqiao Jiang,Jing Zhu,Yuehua Li,Lei Dai,Wei Meng,Ling Wang,Suqin Liu
Graphical P doped CNTs are prepared as catalysts for VO 2+ /VO 2 + redox reaction for vanadium redox flow batteries (VRFB) by high-temperature pyrolysis at different temperatures. The electrocatalytic properties of CNTs for the VO 2+ /VO 2 + redox reaction are significantly enhanced by P doping. The sample treated at 800 °C exhibits the highest electrocatalytic activity. This sample can act as superior catalyst to improve the energy storage performance of VRFBs. In this paper, phosphorus doped (P doped) multi-walled carbon nanotubes (CNTs) were prepared and investigated as catalyst for VO 2+ /VO 2 + redox reaction for vanadium redox flow batteries (VRFB). X-ray photoelectron spectroscopy (XPS) confirms the equable incorporation of P atoms into carbon layers of the CNTs, and that P doping has no obvious effect on the morphologies of the CNTs. The results of cyclic voltammetry and electrochemical impedance spectroscopy indicate that the electrocatalytic properties of the CNTs are significantly enhanced for the VO 2+ /VO 2 + redox couple by P doping. The sample treated at 800 °C (CNTs-P8) exhibits the highest electrocatalytic activity, with two times higher peak currents for the redox reaction catalyzed by CNTs-P8 deposited on glassy carbon than for pristine CNTs. A dynamic cell using the CNTs-P8 catalyst for VO 2+ /VO 2 + redox couple was assembled and the cell performance was evaluated. This cell exhibits better electrochemical properties including higher discharge capacity and energy efficiency, especially at high current density. The average energy efficiency of the cell for 50 cycles increases by 4.2 % at 50 mA cm −2 by using CNTs-P8. This study demonstrates that the P doped CNTs are an efficient and promising catalyst material for VO 2+ /VO 2 + redox reaction in VRFB systems.
研究领域:
材料科学
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电化学
·
能源存储
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产品关联
DOI
高影响因子
Materials Today Physics
·
2023
·
IF 11.5
Jing Huang,Guanchao He,Kang Huang,Minmin Yan,Zhongkun Zhao,Hongtao Sun,Gonglan Ye,Huilong Fei
The electrocatalytic activity of the electrode materials towards the vanadium redox couples is a major factor in determining the performance of vanadium redox flow batteries (VRFBs). Herein, we report the employment of iron single atoms supported on a monolithic porous graphene film (Fe 1 -PGF) as electrodes for catalyzing the VO 2+ /VO 2 + redox couple . The high intrinsic catalytic activity of the atomic Fe sites, the superior surface hydrophilicity , along with the enhanced mass transfer efficiency and exposure of active sites benefited from the porous structure , endow the Fe 1 -PGF electrode with improved electrochemical performance compared to metal-free PGF counterpart and commercial graphite felt electrode. Consequently, the single-cell battery assembled with Fe 1 -PGF exhibits a high voltage efficiency (77.96%) and energy efficiency (70.27%) at the current density of 60 mA cm −2 as well as lower overpotential and higher rate capability compared to the control samples. This study demonstrates that single atom catalysts (SACs) are promising candidates for catalyzing the vanadium redox couples in VRFBs and motivates the exploration of SACs in other types of redox flow batteries.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
OPTICS EXPRESS
·
2024
·Vol. 32
·期 6
·9995-10004
·
IF 3.2
Jiawei Huang,Rui Li,Hengchang Zhang,Ying Wu,Yunxia Wang,Yunxia Wang,Changchun Yan,Changchun Yan,Caiqin Han,Caiqin Han
We present a design of middle-infrared modulation absorbers based on vanadium dioxide (VO2). By using the electron beam evaporation technique, the Ag/SiO2/VO2/Ag/VO2 multilayer structure can achieve double band strong absorption in the mid-infrared, and dynamically adjust the absorption performance through VO2. The simulation results demonstrate a remarkable absorption rate of 91.8% and 98.9% at 9.09 µm and 10.25 µm, respectively. The high absorption is elucidated by analyzing the field strength distribution in each layer. Meanwhile, based on the phase change characteristics of VO2, the absorber has exceptional thermal regulation, with a remarkable 78% heat regulation range in the mid-infrared band. The size altering of the absorbing layer is effective in enhancing and optimizing the structure's absorption performance. The structure is used to characterize probe molecules of CV and R6 G by mid-infrared spectroscopy, which illustrates an impressive limit of detection (LOD) of 10−7 M for both substances. These results provide valuable insights for designing future high-performance tunable optical devices.
研究领域:
光学
·
材料科学
·
光谱学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Weiliang Zhou,Xiaojie Li,Xuan Li,Jiaxin Shao,Hengpan Yang,Xiaoyan Chai,Qi Hu,Chuanxin He
The rational design of bifunctional electrocatalysts is essential to achieve efficient hydrogen production from water splitting. Here, inspired by cocatalysts widely utilized in photocatalysis , we designed a heterostructure comprising amorphous VO 2 and crystalline NiS 2 , aiming at using VO 2 cocatalyst to boost activity of NiS 2 for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Intriguingly, we found that VO 2 displayed different co-catalytic function in boosting the OER and HER. Specifically, the VO 2 optimized the binding energy of hydrogen intermediate on NiS 2 and thus improved the HER activity. As for the OER, the amorphous VO 2 was easily dissolved in the KOH electrolyte, resulting in the generation of abundant oxygen vacancies in the in-situ generated active phase of NiOOH from NiS 2 , thereby drastically enhancing the OER activity. Consequently, the obtained VO 2 –NiS 2 @CC displayed excellent performance for overall water splitting, with a low voltage of 1.53 V at 10 mA cm −2 .
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2024
·
IF 6.3
Jia Gao,Hainan Zhang,Xiangge Han,Shuhui Liang,Weiqi Zhou,Shuliang Dou,Jiazhi Wang,Yao Li
Dynamic infrared radiation has significantly contributed to thermal comfort by adaptively radiating heat into space without necessitating external energy consumption. This study introduces a novel approach to fabricate dynamic infrared radiation-regulated materials using VO 2 nanorods. The VO 2 nanorods were synthesized via a conventional hydrothermal method. XRD and SEM analyses confirmed the high crystallinity and uniform size of the VO 2 nanorods. HRTEM measurements revealed that the nanorods had an approximate length of 1 μm and a width of 100 nm. These nanorods were combined with KBr and pressed into a tablet form. Subsequent thermal imaging was conducted to assess their dynamic infrared radiation regulation capability. Remarkably, the optimized variation in emissivity for the VO 2 -based tablets reached up to 0.46. And the Mie scattering theory was used to interprete the insight mechanism. It seems that the Q abs of VO 2 nanorod before and after phase transition dominate the dynamic infrared radiation regulation ability at different temperatures. This finding offers a novel, straightforward, and highly efficient energy-saving solution for thermal management systems.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Energy & Environmental Science
·
2012
·Vol. 5
·期 8
·8234-8237
·
IF 9.61
Yanfeng Gao,Shaobo Wang,Litao Kang,Zhang Chen,Jing Du,Xinling Liu,Hongjie Luo,Minoru Kanehira
VO2/ATO/polymer thermochromic flexible foils for smart window application were prepared by casting VO2 and Sb : SnO2 (ATO) nanoparticles. The foils exhibit an increased solar-heat shielding ability, causing a 20% decrease in solar transmittance at an ATO content of 9%, while retaining an excellent solar modulation ability (6.9%). This development represents a breakthrough for applications to smart windows.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Jie Chen,Baoquan Xiao,Changfa Hu,Hangda Chen,Juanjuan Huang,De Yan,Shanglong Peng
VO2 (B) electrode material has relatively high capacity and good cycle stability. However, its poor rate performance limits its further development because of the strong interaction between zinc ions and the main lattice of VO2 (B). Herein, considering the design principle of rate performance improvement, we furnished a different scheme from a previous multistep method of the synthesis–modification strategy of pure VO2 (B). VO2@V2C 1D/2D heterostructure was constructed by controllable partial oxidation of V2C by a one-step hydrothermal method. The unique 1D/2D heterostructure improves diffusivity and reduces the diffusion size of zinc ions at the same time, which significantly improved the rate performance of VO2. The situation at the heterostructure interface is analyzed by Raman spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet photoelectron spectroscopy. Combined with cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic intermittent title technology tests, the promotion mechanism for the rate performance of the derived VO2 is further explained. In addition, it is found that V2C MXene can be electrochemically activated when the voltage reaches 1.24 V. By further widening the voltage window to activate V2C, VO2@V2COx heterostructure was obtained, which realizes high capacity and maintains high rate performance in aqueous zinc-ion batteries. This work provides key insights for the design of high-rate-performance electrode materials for aqueous zinc-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Xue Yang,Jian Zou
The facile fabrication of VO 2 thermochromic film with outstanding solar modulation ability along with high luminous transmittance is still challenging for the large-scale practical application of VO 2 films. The dispersity of VO 2 in polymer matrix can determine the optical performance of VO 2 thermochromic film to some content. Herein, the VO 2 nanoparticles were prepared by one-step hydrothermal method and directly dispersed in polyurethane (PU) sol with different viscosity to cast the VO 2 composite film . The solar modulation ability (ΔT sol ) almost increased linearly with the logarithm of viscosity for PU sol, and ΔT sol can be enhanced to 14.5% from 6.6% while maintaining a high T lum beyond 54% only by changing the content of thickener. The ΔT sol increased further to 20.0% for the three layers film. The enhanced optical performances might be attributed to the good dispersity of VO 2 nanoparticles and pore structure in PU matrix. This study provides a novel strategy in preparing VO 2 film for the applications in smart windows.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Danting Xu,Xia Zhu,Jiakun An,Gaoyu Chen,Jianchun Bao,Xiangxing Xu
As a narrow band semiconductor at room temperature and a metallic material above ∼68 °C, functional VO2 films are widely investigated for smart windows, whereas their potential for ultraviolet–visible–infrared (UV–vis–IR) broad spectral photodetectors has not been efficiently studied. In this report, photodetectors based on VO2–ZnO nanocrystal composite films were prepared by nanocrystal-mist (NC-mist) deposition. An enhanced photodetection switching ratio was achieved covering the ultraviolet to infrared wavelength. Due to the synergetic effect of nanosize, surface, phase transition, percolation threshold, and the band structure of the heterojunction, the transfer and transport of photogenerated carriers modulate the device performance. This study probes new chances of applying VO2-semiconductor-based nanocomposites for broad spectral photodetectors.
研究领域:
材料科学
·
光电子学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Materials Technologies
·
2023
·Vol. 8
·期 21
·2300898
·
IF 6.8
Yuxin Wang,Yang Hong,Xiaokang Hu,Yang Ye,Peike Wang,Jingjing Luo,Ao Yin,Zhongqi Ren,Haipeng Liu,Xue Qi,Jiang Liu,Sisi He,Suzhu Yu,Jun Wei
Long-term effective temperature monitoring using a flexible wearable temperature sensor is critical for future health monitoring, noninvasive clinical biomonitoring, disease diagnosis, and so on. Thermistors have the merits of simple structure, ease of preparation and great sensitivity, but the preparation of thermistors with good flexibility is often at the expense of their sensitivity and requirement of high temperature. Herein, a flexible temperature sensor with stability and high sensitivity by spraying VO 2 /PEDOT:PSS composites on an SBS electrospinning substrate is reported. The sensor exhibits high thermal sensitivity (−2.712%/°C), high precision (85 mK), ultra-fast response time (1 s) and recovery time (2.5 s), enabling accurate real-time temperature detection and meeting the need for long-term temperature monitoring and tracking. As a proof of concept, this sensor is applied to monitor human skin temperature, breathing rate, and temperature recognition, and as a temperature-based input keyboard, demonstrating its tremendous potential to further develop personalized flexible sensors.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2022
·
IF 3.656
Tao Zhang,Qinggang Li
NH 4 VO 3 is an important vanadium source for the preparation of VO 2 . In the previous studies, the extra gas or solid reagents consumption is necessary for the preparation of VO 2 by using NH 4 VO 3 as vanadium source. The current work proposed a facile way for the fabrication of VO 2 (M) by the thermolysis of NH 4 VO 3 under the sealed atmosphere without extra gas or solid reagents consumption. The VO 2 (M) could be successfully synthesized by two step—thermolysis of NH 4 VO 3 at 400 °C under the sealed condition and heat treatment of VO 2 (B) at 500 °C under the N 2 condition. The dosage of NH 4 VO 3 and decomposition temperature had significant influences on the thermolysis process under the sealed condition. The NH 3 produced by the thermolysis provided a protective atmosphere that prevented the oxidization of VO 2 (B) by residual O 2 in the sealed reactor. Furthermore, the VO 2 (M) could be prepared directly under the sealed atmosphere by increasing reaction temperature to 700 °C. In this process, NH 4 VO 3 underwent a phase transition as the follows: NH 4 VO 3 →ammonium vanadium bronze→VO 2 (B)→VO 2 (M). The directly synthesized VO 2 (M) at 700 °C by the thermolysis of NH 4 VO 3 under the sealed condition showed great environmental stability and phase transition performance.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2012
·
IF 4.542
Jing Du,Yanfeng Gao,Zhang Chen,Litao Kang,Zongtao Zhang,Hongjie Luo
Application of VO 2 to smart windows calls for an enhancement of both luminous transmittance ( T lum ) and solar transmittance modulation (Δ T sol ). These two properties are related to optical constants , microstructure and film thickness. In this article, VO 2 -based films with increased microroughness are prepared by polymer assisted deposition , and ZnCl 2 is added to the precursor solution to control the microstructure of the films. Addition of ZnCl 2 increases the microroughness of films through phase separation, which largely decreases the refraction index and the reflectivity of the films, resulting in enhanced luminous transmittance and solar transmittance modulation; two films with balanced optical performance show T lum =50.5% and Δ T sol =11.3%, and T lum =59.3% and Δ T sol =10.5%, respectively. Moreover, this kind of microstructure control has no influence on doping VO 2 , which is proven by the deposition and characterization of W-doped VO 2 -based films. By the formation of a W-doped VO 2 /F:SnO 2 /glass multilayer stack, a film shows excellent thermochromic properties and low emissivities; typically, a film with a phase transition temperature, T lum , Δ T sol of 43.4 °C, 30.0%, 8.82%, respectively, and emissivity of 0.20 for monoclinic and 0.33 for rutile phase is successfully prepared.
研究领域:
材料科学
·
光学工程
✓ 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）