scholarly journals Hydrothermal growth of VO2 nanoplate thermochromic films on glass with high visible transmittance

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jiasong Zhang ◽  
Jingbo Li ◽  
Pengwan Chen ◽  
Fida Rehman ◽  
Yijie Jiang ◽  
...  

Abstract The preparation of thermochromic vanadium dioxide (VO2) films in an economical way is of interest to realizing the application of smart windows. Here, we reported a successful preparation of self-assembly VO2 nanoplate films on TiO2-buffered glass by a facile hydrothermal process. The VO2 films composed of triangle-shaped plates standing on substrates exhibit a self-generated porous structure, which favors the transmission of solar light. The porosity of films is easily controlled by changing the concentration of precursor solutions. Excellent thermochromic properties are observed with visible light transmittance as high as 70.3% and solar modulating efficiency up to 9.3% in a VO2 film with porosity of ~35.9%. This work demonstrates a promising technique to promote the commercial utilization of VO2 in smart windows.

2019 ◽  
Vol 19 (6) ◽  
pp. 3356-3366
Author(s):  
Onruthai Srirodpai ◽  
Jatuphorn Wootthikanokkhan ◽  
Saiwan Nawalertpanya

In this study, an alternative approach is presented for developing thermo-chromic film, based on ethylene vinyl acetate copolymer (EVA) and vanadium dioxide (VO2) composite, with enhanced oxidation stability and compatibility. The neat monoclinic nanocrystalline VO2 particles were firstly prepared via a hydrothermal process, using citric acid as a reducing agent. After that, the synthesized VO2 particles were characterized, prior to mixing with maleic anhydride grafted PE. The crystalline structure, morphology and thermochromic performance of the polyethylene coated vanadium dioxide (VO2@PE) particles were then verified by SEM, TEM, DSC, XRD, FTIR techniques. After coating, a better oxidation stability of the VO2 particles was noted while the thermo-chromic performance of the VO2@PE was also maintained. After mixing with EVA, the percentage strain and tensile toughness of the VO2@PE based EVA films was the highest, followed by those of the uncoated VO2-based EVA films and the neat EVA, respectively. The VO2@PE-based films also maintained the thermochromic behavior of the monoclinic VO2. The above improvements were achieved at the expense of percentages of visible light transmittance and gel content of the EVA. This is the first report of the EVA/VO2-based thermo-chromic film, which is tougher and more stable toward oxidation than the prior state of the art. This composite film has the potential to be used as a kind of a specialty lamination material for smart windows and energy efficiency in buildings.


2010 ◽  
Vol 09 (05) ◽  
pp. 543-547 ◽  
Author(s):  
JUN WANG ◽  
SHIHE CAO ◽  
SIHUA XIA ◽  
NING GAN

Chain-like nickel arrays assembled from magnetic Ni spheres were successfully prepared through a facile hydrothermal process at 200°C under a 0.25 T external magnetic field. The external magnetic field is strongly believed to be the driving force of the self-assembly. The sample was highly crystalline as confirmed by the X-ray diffraction (XRD) patterns. The scanning electron microscope (SEM) and transmission electron microscope (TEM) images show that all Ni spheres are closely interconnected to form chains, with ~ 950 nm in diameter and ~ 1 cm in length, which arrange into vertical arrays on the silicon substrate. The coercivity and remnant magnetization ratio of the sample, 670 Oe and 0.612, respectively, are substantially higher than for the sample prepared without an applied external magnetic field (68 Oe and 0.336). Such enhancements can be attributed to their novel superstructure, shape anisotropy, reduced demagnetization factor, etc. This process can be used to fabricate large arrays of uniform chains of magnetic materials and modulate their magnetic properties.


2018 ◽  
Vol 6 (29) ◽  
pp. 7896-7904 ◽  
Author(s):  
Huiyan Xu ◽  
Zhengfei Dai ◽  
Chen Wang ◽  
Kewei Xu ◽  
Fei Ma ◽  
...  

Vanadium dioxide (VO2) is a phase-transition material exhibiting great potential in the field of smart windows for energy saving.


NANO ◽  
2016 ◽  
Vol 11 (06) ◽  
pp. 1650071 ◽  
Author(s):  
Wei Zhang ◽  
Chao Hu ◽  
Jie Tan ◽  
Zhujun Fan ◽  
Fangli Chi ◽  
...  

The composite [Formula: see text]-FeOOH nanorods/Ag3PO4 photocatalyst has been successfully fabricated through a facile hydrothermal process combined with a successive in situ precipitation technique. The SEM and TEM images show that Ag3PO4 particles have been successfully loaded on the surface of FeOOH nanorods. The photocatalytic activities of the [Formula: see text]-FeOOH/Ag3PO4 composite were investigated for their efficiency on the degradation of Rhodamine B (RhB) under ultra-violet light and visible light irradiation, and the results showed that the [Formula: see text]-FeOOH/Ag3PO4 composite possessed remarkable photocatalytic activities. The enhanced photocatalytic activity can be attributed to the strong absorption in visible light and the effective separation of photogenerated hole–electron pairs between Ag3PO4 and [Formula: see text]-FeOOH.


RSC Advances ◽  
2017 ◽  
Vol 7 (54) ◽  
pp. 34096-34103 ◽  
Author(s):  
Yuehan Su ◽  
Ping Chen ◽  
Fengliang Wang ◽  
Qianxin Zhang ◽  
Tiansheng Chen ◽  
...  

A novel visible-light-driven CDs/TiO2/g-C3N4 photocatalyst was successfully synthesized by doping CDs in TiO2 nanoparticles and the surface of g-C3N4 nanosheets via a facile hydrothermal process and was confirmed by characterization methods.


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Yuxi Zhao ◽  
Rongcheng Liu ◽  
Fan Yan ◽  
Dawei Zhang ◽  
Junjin Liu

The windblown sand-induced degradation of glass panels influences the serviceability and safety of these panels. In this study, the degradation of glass panels subject to windblown sand with different impact velocities and impact angles was studied based on a sandblasting test simulating a sandstorm. After the glass panels were degraded by windblown sand, the surface morphology of the damaged glass panels was observed using scanning electron microscopy, and three damage modes were found: a cutting mode, smash mode, and plastic deformation mode. The mass loss, visible light transmittance, and effective area ratio values of the glass samples were then measured to evaluate the effects of the windblown sand on the panels. The results indicate that, at high abrasive feed rates, the relative mass loss of the glass samples decreases initially and then remains steady with increases in impact time, whereas it increases first and then decreases with an increase in impact angle such as that for ductile materials. Both visible light transmittance and effective area ratio decrease with increases in the impact time and velocities. There exists a positive linear relationship between the visible light transmittance and effective area ratio.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 440
Author(s):  
Yuan Deng ◽  
Shi-Qin Li ◽  
Qian Yang ◽  
Zhi-Wang Luo ◽  
He-Lou Xie

Smart windows can dynamically and adaptively adjust the light transmittance in non-energy or low-energy ways to maintain a comfortable ambient temperature, which are conducive to efficient use of energy. This work proposes a liquid crystal (LC) smart window with highly efficient near-infrared (NIR) response using carbon nanotubes grafted by biphenyl LC polymer brush (CNT-PDB) as the orientation layer. The resultant CNT-PDB polymer brush can provide the vertical orientation of LC molecules to maintain the initial transparency. At the same time, the smart window shows a rapid response to NIR light, which can quickly adjust the light transmittance to prevent sunlight from entering the room. Different from common doping systems, this method avoids the problem of poor compatibility between the LC host and photothermal conversion materials, which is beneficial for improving the durability of the device.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4079
Author(s):  
Radhalayam Dhanalakshmi ◽  
Nambi Venkatesan Giridharan ◽  
Juliano C. Denardin

Magnetic-field-accelerated photocatalytic degradation of the phenol red (PR) as a model organic pollutant was studied using rare-earth elements modified BiFeO3 (Bi1−xRxFeO3 (R = Ce, Tb; x = 0.0, 0.05, 0.10 and 0.15); BFO: RE) nanostructures. The nanostructures were prepared via the hydrothermal process and their morphological, structural, functional, optical and magnetic features were investigated in detail. The effect of magnetic fields (MFs) on photocatalysis were examined by applying the different MFs under visible light irradiation. The enhanced photodegradation efficiencies were achieved by increasing the MF up to 0.5T and reduced at 0.7T for the compositions x = 0.10 in both Ce and Tb substituted BFO. Further, mineralization efficiencies of PR, reproducibility of MF-assisted photocatalysis, stability and recyclability of BFO: RE nanostructures were also tested.


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