ACS Applied Nano Materials
·
2023
·
IF 5.9
Xiaohui Sun,Xueying Zhao,Xuyang Zhang,Guohua Wu,Xianhui Rong,Xiangwei Wang
Ti3C2Tx MXene is a potential microwave absorption material due to its unique physical and chemical properties. However, the impedance mismatch of MXene results in low microwave absorption. In this work, 2D/2D MXene@TiO2 composites were synthesized via a simple hydrothermal oxidation method, TiO2 is derived in situ from MXene without adding any additional Ti precursors. TiO2 with low permittivity can effectively regulate the impedance matching and enhance loss mechanisms. The MXene@TiO2-6 h composite shows a reflection loss (RL) of −58.3 dB at 11.36 GHz with a thickness of 1.75 mm, and the maximum effective absorption bandwidth (EAB) is 4.08 GHz (13.92–18 GHz) at 1.26 mm. Furthermore, the 2D/2D composite can obtain efficient microwave absorption at different frequencies by adjusting the thickness; RL can reach −39.1 dB at 5.04 GHz with a thickness of 3.5 mm. The radar cross section (RCS) of MXene@TiO2-6 h is lower than −19 dB m2 at −60–60°, and the minimum RCS is −56 dB m2 at 15°. This work provides a valuable experience in developing microwave absorption materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 25
·期 35
·23761-23769
·
IF 3.3
Juanqin Xue,Peng Wang,Wen Cheng,Long Shi,Qiang Bi
TiO2/BiOI/CA electrodes with improved conductivity, reduced photoelectron–hole recombination rates, and increased reaction sites based on p–n type heterojunctions were constructed on carbon aerogels (CA) as photoelectrode substrates. Characterization based on ultraviolet-visible diffuse reflectance spectroscopy, photocurrent measurements, and impedance analysis showed that the TiO2/BiOI/CA photoelectrode with a Ti/Bi mole ratio of 0.4 exhibited the best visible light absorption, lowest photogenerated electron–hole pair recombination rate, and strongest photocatalytic degradation, with 90.4% degradation of phenol under 120 min of light. Moreover, the stability of this electrode remained at a high level. This was mainly because the energy levels of TiO2 and BiOI matched each other and the p–n heterojunction formed adjusted the energy band structure of the composite material, widened the electron transfer path, formed an internal electric field between the phase interfaces, had a higher electron transfer rate, and reduced the photogenerated electron–hole recombination rate. Since ˙OH and ˙O2− are the main active substances in the degradation of phenol, the TiO2/BiOI/CA photoelectrodes had higher degradation efficiency than BiOI/CA electrodes. This study provides a unique concept for the treatment of organic pollutant wastewater and electrode design for photoelectrocatalysis.
研究领域:
材料科学
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环境科学
·
光催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Juan Yang,Zhihui Wen,Xiaoxiao Shen,Jun Dai,Yao Li,Yingjie Li
A series of graphene-TiO 2 nanocomposites (GR-TiO 2 ) with different TiO 2 dimensionalities (including TiO 2 nanoparticles, nanotubes and nanosheets) and GR weight ratios have been prepared via the analogous in-situ synthesis approach. For the first time, a systematic comparison among GR-TiO 2 NP, GR-TiO 2 NT and GR-TiO 2 NS composite photocatalysts toward ultraviolet-driven CO 2 reduction and visible-light-induced benzylamine oxidation has been carried out based on a reasonable benchmark framework. The influences of TiO 2 dimensionalities and GR weight ratios on photocatalytic redox reactions are systematically investigated. Moreover, direct comparisons among GR-TiO 2 NP, GR-TiO 2 NT and GR-TiO 2 NS composites are also conducted in terms of reactive species generation, transient photocurrent response and interfacial charge-transfer kinetics. Due to intimate interfacial contact between graphene and two-dimensional (2D) TiO 2 nanosheets, 2D-2D GR-TiO 2 NS nanocomposites possess superior electronic coupling compared to 2D-0D GR-TiO 2 NP and 2D-1D GR-TiO 2 NT samples, which results in rapid photoinduced charge-transfer and remarkably improved photocatalytic activity for CO 2 reduction under ultraviolet irradiation. On the other hand, because of large BET surface area, GR-TiO 2 NT composites possess stronger adsorption for benzylamine and the resulting visible-light absorption, leading to greater photocatalytic activity toward selective oxidation of benzylamine under visible light illumination. Overall, the results suggest that TiO 2 nanomaterial dimensionality plays the key role in determining the interfacial charge-transfer and reaction specificity of GR-TiO 2 composite photocatalysts.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
·
2020
·Vol. 30
·期 9
·3378-3387
·
IF 1.941
Ai Cuiling,Wu Xuefang,Ke Yuting,Lei Yingjie,Shao Xiangwen
The photocatalyst sorbic acid (SA)/titanium dioxide (TiO 2 ) was successfully synthesized by sol–gel method and characterized. The composite exhibited regularly spherical particles with the size of 50 nm and the specific surface area of 90.3 m 2 g −1 , furthermore, it showed mesoporous structure and significantly improved dispersion. SA was grafted on TiO 2 surface by –COOTi and TiO 2 existed as pure anatase phase in the composite. The addition of SA made the band gap of TiO 2 increased from 3.03 to 3.35 eV, which indicting that the composite exhibited a strong response to the ultraviolet light. The optimum preparation parameters of the catalyst were as follows: n(Ti):n(SA) = 1:0.05, ethanol 60 mL, glacial acetic acid 40 mL, hydrothermal temperature 180 °C, hydrothermal time 12 h. The composite could reach the 4.31 log reduction of E. coli , with the optimum catalyst dosage of 0.7 g L −1 , irradiated by UV light for 60 min. SA/TiO 2 was an environmentally friendly, non-toxic and safe sterilized nanocomposite material appropriate for future bactericidal applications, providing a new way to effectively increase the dispersion of TiO 2 particles to achieve superior photocatalytic sterilization efficiency.
研究领域:
材料科学
·
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2025
·
IF 4.6
Yunlan Xu,Jiaxin Mou,Lin Dong,Qingmei Qiao,Dengjie Zhong
The performance of photocatalytic fuel cell (PFC) depends on photoanode, which is the key to generate photoexcited carriers and degrade organic wastes. In this study, ZnIn 2 S 4 nano-bandgap semiconductor and polypyrrole were used to modify TiO 2 to prepare polypyrrole/ZnIn 2 S 4 /TiO 2 /Ti photoanode to increase its photo-response range and the separation of photoexcited carriers. The PFC with polypyrrole/ZnIn 2 S 4 /TiO 2 /Ti photoanode and copper cathode was built to degrade RhB and generate electricity. The RhB removal rate, open-circuit voltage, short-circuit current density, and maximum power density of the photocatalytic fuel cell were 94.6 % (1 h), 0.47 V, 0.23 mA cm −2 and 21.11 μW cm −2 , respectively. The improvement of PFC performance is attributed to the good visible-light responsive properties of polypyrrole/ZnIn 2 S 4 .The presence of polypyrrole acts as both an electron donor and a hole acceptor, which provides an ideal pathway for the separation and transmission of photogenerated carriers. The synergistic effect of polypyrrole, ZnIn 2 S 4 and TiO 2 eventually increases the photocatalytic ability of the PFC. This research can offer reference for the study of TiO 2 -based efficient visible light responsive PFC.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Mu Liu,Liren Zheng,Xiaolei Bao,Zeyan Wang,Peng Wang,Yuanyuan Liu,Hefeng Cheng,Ying Dai,Baibiao Huang,Zhaoke Zheng
Atomic layer deposition (ALD) technique has been proved to be an efficient method to synthesize or modify catalyst. In this study, Cu was loaded on different TiO 2 substrates, pristine TiO 2 and black TiO 2 (denoted as H-TiO 2 ) to achieve better CO 2 photocatalytic reduction performance. Both TiO 2 @Cu and H-TiO 2 @Cu exhibited dramatic enhancement for CO and CH 4 production. The peculiar phenomenon of TiO 2 outperforming H-TiO 2 after ALD loading was further studied by a series of characterization methods. Even though H-TiO 2 showed superior performance for photocatalytic CO 2 reduction than TiO 2 , pristine TiO 2 loaded with more Cu 0/+ after ALD deposition surpassed the performance of H-TiO 2 @Cu which possessed less amount of Cu 0/+ and more Cu 2+ . Cu 0/+ is proved to be the crucial factor for CO 2 reduction and it is capable of overshadowing the influence of Ti 3+ and V o . These results indicate that not only will ALD technique significantly enhance the CO 2 reduction performance after Cu deposition, but the substrate employed for loading and the chemical state of loaded material will also influence the subsequent catalytic performance. In addition, our result provides additional experiment evidence for justifying the significance of Cu 0/+ in photocatalytic CO 2 reduction reaction.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Jingjing Wang,Yun Wang,Wei Wang,Tong Peng,Jianjun Liang,Ping Li,Duoqiang Pan,Qiaohui Fan,Wangsuo Wu
The photocatalytic reduction of U(VI) is recognized as an economical and effective way for U(VI) removal/recovery from solutions. To improve the photocatalytic activity of TiO 2 under visible light, TiO 2 was hydrogenated by NaBH 4 to generate Ti 3+ self-doped black TiO 2 (BT n ). The self-doped Ti 3+ alongside oxygen vacancies (Ov) could act as interband level to increase visible light capture and reduce the recombination of photogenerated carriers. The obtained BT n samples showed high performance for U(VI) elimination under near neutral conditions, and held an outstanding anti-interference for U(VI) over competing metal cations and anions. Methanol and ethanol could act as sacrificial donors, being favorable for the photocatalytic reduction of U(VI), while the presence of EDTA inhibited the photoreduction of U(VI). The BT n photocatalysts showed relatively high stability and reusability during the photocatalysis and elution processes. The XPS, TEM and XRD results revealed that U(VI) was photo-reduced to form UO 2 on the surface of BT n . This work may serve as an important reference for improving the photocatalytic reactivity of TiO 2 as well as for the efficient removal/recovery of U(VI) from aqueous solutions.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 11
·2801
·
IF 5.076
Guang Feng,Mengyun Hu,Shuai Yuan,Junyi Nan,Heping Zeng
Hydrogenated crystalline TiO2with oxygen vacancy (OV) defect has been broadly investigated in recent years. Different from crystalline TiO2, hydrogenated amorphous TiO2−xfor advanced photocatalytic applications is scarcely reported. In this work, we prepared hydrogenated amorphous TiO2−x(HA-TiO2−x) using a unique liquid plasma hydrogenation strategy, and demonstrated its highly visible-light photoactivity. Density functional theory combined with comprehensive analyses was to gain fundamental understanding of the correlation among the OVconcentration, electronic band structure, photon capturing, reactive oxygen species (ROS) generation, and photocatalytic activity. One important finding was that the narrower the bandgap HA-TiO2−xpossessed, the higher photocatalytic efficiency it exhibited. Given the narrow bandgap and extraordinary visible-light absorption, HA-TiO2−xshowed excellent visible-light photodegradation in rhodamine B (98.7%), methylene blue (99.85%), and theophylline (99.87) within two hours, as well as long-term stability. The total organic carbon (TOC) removal rates of rhodamine B, methylene blue, and theophylline were measured to 55%, 61.8%, and 50.7%, respectively, which indicated that HA-TiO2−xexhibited high wastewater purification performance. This study provided a direct and effective hydrogenation method to produce reduced amorphous TiO2−xwhich has great potential in practical environmental remediation.Keywords:hydrogenated TiO2−x;oxygen vacancy;hydrogenation;liquid plasma;band structure
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 16
·2200903
·
IF 10.05
Siyuan Huang,Renfu Zhang,Peipei Shao,Yiwen Zhang,Rui-Tao Wen
Electrochromic performance fading is inevitable upon extended cycling, and the limited lifetime greatly prevents large-scale commercialization of electrochromism-based devices. Here the origin of the performance degradation is uncovered and the performance restoration in TiO 2 thin films is explored. It is shown that, depending on the applied potential windows, the inserted ions are immobilized in α - traps resulting in a monotonous degradation of colored state, or immobilized in b - and modified α - traps leading to mutual degradation of colored and bleached state of the films. It is found by releasing the resided ions in various traps, the initial performance can be restored accordingly. Moreover, reversible sites and all traps are demonstrated to be interconvertible through an ion trapping and detrapping process. These results provide a general scope in understanding the electrochromism in oxide thin films and offer the scheme for potential traps control or even elimination, aiming at superior electrochromic devices.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2015
·
IF 2.719
Xi Li,Jie Li,Yingchun Li,Kai Xia
8-hydroxyquinoline aluminum/nano-TiO 2 composites were prepared via in situ. In order to make a better combination of the two component, Octavinyl-T8-silsesquioxane (8-vinyl POSS) was introduced into the composite system . The structure and properties of the samples were characterized by XRD , SEM, XPS , UV–visible absorption, Fluorescence spectra and Time-resolved emission-decay. These results show both β-phase and γ-phase of Alq 3 exist in the composite products. Meanwhile, the addition of nano-TiO 2 and 8-vinyl POSS does not change the crystalline and structure of as-prepared Alq 3 . Interestingly, however, XPS spectra shows that two new kinds of interaction forces emerge after the addition of 8-vinyl POSS, owing to the formation of Al–O–Si and Si–O–Ti bond, presumably. Besides, the emission intensity of Alq 3 /nano-TiO 2 and Alq 3 /8-vinyl POSS/nano-TiO 2 increases by 22% and 33%, respectively. The addition of TiO 2 and 8-vinly POSS will not affect the position of emission peak, but will increase the transmission efficiency in electron–hole pairs. In the meantime, surprisingly, the modified Alq 3 has a longer lifetime than as-prepared Alq 3 .
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Kexin Wang,Zhongge Luo,Bin Xiao,Tong Zhou,Jianhong Zhao,Congcong Shen,Dequan Li,Zhishi Qiu,Jin Zhang,Tianwei He,Qingju Liu
TiO 2 photocatalysts are of great interest in the fields of environmental purification, new energy and so on, because of their non-toxicity, high stability, high redox ability and low cost. However, the photogenerated carriers are severely recombined, which limits the application of TiO 2 photocatalysts. Herein, S-scheme Cu 3 P/TiO 2 heterojunction composites were successfully synthesized by a simple and efficient microwave hydrothermal method, and the results show that the hydrogen production rate of Cu 3 P/TiO 2 is 5.83 mmol∙g −1 ∙h −1 under simulated sunlight irradiation, which is 7.3 and 83.3 times higher than that of pure TiO 2 and Cu 3 P, respectively. This excellent performance is derived from the internal electric field (IEF) and energy band bending generated by the S-scheme heterojunction formed between Cu 3 P and TiO 2 . The density functional theory (DFT) calculation indicates that the Cu 3 P possess smaller work function and more negative conduction band (CB) position than that of TiO 2 , which is very conducive to greatly improve the H + reduction ability and hydrogen production performance. This work provides a new idea for the reveal of electron transfer paths and active sites in S-scheme heterojunctions and deepens the mechanism understanding.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2014
·
IF 5.9
Weijun Ke,Guojia Fang,Jing Wang,Pingli Qin,Hong Tao,Hongwei Lei,Qin Liu,Xin Dai,Xingzhong Zhao
A perovskite solar cell with a thin TiO2 compact film prepared by thermal oxidation of sputtered Ti film achieved a high efficiency of 15.07%. The thin TiO2 film prepared by thermal oxidation is very dense and inhibits the recombination process at the interface. The optimum thickness of the TiO2 compact film prepared by thermal oxidation is thinner than that prepared by spin-coating method. Also, the TiO2 compact film and the TiO2 porous film can be sintered at the same time. This one-step sintering process leads to a lower dark current density, a lower series resistance, and a higher recombination resistance than those of two-step sintering. Therefore, the perovskite solar cell with the TiO2 compact film prepared by thermal oxidation has a higher short-circuit current density and a higher fill factor.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
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