JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2021
·
IF 4.464
Ping Qiu,Shouwu Xu,Kaili Zhang,Zhongyuan Jiang,Daming Gong,Changfeng Chen
Cu@Cu 2 O films were prepared by electrochemical deposition method. The obtained Cu@Cu 2 O films were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), confocal Raman spectroscopy (CRS), UV–visible absorption spectroscopy and Photoluminescence (PL) spectroscopy. Electrochemical measurements were performed under intermittent visible light illumination to assess the photoelectrochemical cathodic protection effect of the prepared Cu@Cu 2 O films. The results indicated that a lower deposition potential could facilitate the reduction of Cu 2 O grain size together with an increase number of Cu. But the deposition potential has no obvious influence on the band-gap of the composite films, which exhibited n-type semiconductor properties. The open circuit potential of 304 stainless steel by coupling with the Cu@Cu 2 O-0.3 V films presented the most negative shift of −179 mV under visible-light illumination. The related photocurrent density was 0.13 mA·cm −2 . The photoelectrochemical conversion mechanism and the photoelectrochemical cathodic protection effects of the Cu@Cu 2 O films were discussed in detail.
研究领域:
材料科学
·
电化学
·
腐蚀与防护
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Xiaoming Liu,Binquan Wu,Xueya Chen,Liushui Yan,Huiqin Guo,Kexin Li,Luping Xu,Jun Lin
In this work, a series of Mn x Cd 1-x S solid solutions as efficient photocatalysts for hydrogen evolution with visible light response were synthesized via a co-precipitation method firstly. Then, the hierarchical Bi 2 MoO 6 /Mn 0.2 Cd 0.8 S heterostructured composite was prepared by combining Mn 0.2 Cd 0.8 S composite with Bi 2 MoO 6 nanocrystalline through a hydrothermal process. The optimized Mn 0.2 Cd 0.8 S composite's photocatalytic activity is more than 3 times of pristine CdS and the prepared Bi 2 MoO 6 /Mn 0.2 Cd 0.8 S nanocomposites exhibited a significantly improved photocatalytic activity for hydrogen evolution from water with visible light response comparing with single Mn 0.2 Cd 0.8 S composite. The optimized photocatalytic activity of Bi 2 MoO 6 /Mn 0.2 Cd 0.8 S composite is around 10 times of pristine CdS. The excellent photocatalytic activity of Bi 2 MoO 6 /Mn 0.2 Cd 0.8 S composite might be ascribed to the well-matched energy band structures of the Bi 2 MoO 6 and Mn 0.2 Cd 0.8 S. Furthermore, the heterojunctions in Bi 2 MoO 6 /Mn 0.2 Cd 0.8 S composite might also do some contributions to improve its photocatalytic activities to some extent. A possible photocatalytic mechanism was proposed. Due to its excellent photocatalytic activity and good stability for hydrogen evolution from water, the obtained hierarchical Bi 2 MoO 6 /Mn 0.2 Cd 0.8 S composite has potential application in photocatalytic hydrogen evolution from water by using solar power.
研究领域:
材料科学
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能源科学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Rui Wang,Jun Shen,Wenjing Zhang,Qinqin Liu,Mingyi Zhang,Zulfiqar,Hua Tang
Artificial Z-scheme heterostructure photocatalysts , inspired by the natural photosynthesis, have been explored for water contamination owing to the efficiency of charge carriers separation and enhanced redox capacity. Herein, a novel step-scheme TiO 2 /W 18 O 49 heterojunction integrating TiO 2 nanosheets and spindle-like W 18 O 49 was prepared via a two-step solvothermal method. The TiO 2 /W 18 O 49 heterojunction with the optimum ratio exhibited excellent photodegradation of RhB higher by a factor of 2.26 and TC degradation higher by a factor of 3.32 than the pristine TiO 2 when exposed to visible light. The reactive free radical trapping experiment indicated •O 2 − was determined to the dominant reactive species. Furthermore, XPS analysis and •O 2 − quantification measurements confirmed a build-in electric field induced step-scheme structure in TiO 2 /W 18 O 49 composites, which effectively enhanced the separation of carriers, thus improved photocatalytic activity. The present study will offer a new perception related to the formation of step-scheme heterostructure for photocatalytic degradation.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2013
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IF 2.39
Yongyong Deng,Youjian Chen,Bingang Chen,Jianhua Ma
In this study, a series of p-CuBi 2 O 4 /n-NaTaO 3 heteronanostructures were synthesized with the grinding–annealing method. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalysts exhibit enhanced photocatalytic activity for methyl blue dye degradation under visible-light irradiation. The highest photocatalytic degradation efficiency was observed when the sample calcined at 500 °C with 50 wt.% CuBi 2 O 4 content. On the basis of the calculated energy band positions, the mechanism of enhanced photocatalytic activity was discussed.
研究领域:
材料科学
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光催化化学
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环境功能材料
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纳米材料
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能源与环境技术
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DOI
高影响因子
Materials Chemistry Frontiers
·
2023
·Vol. 7
·期 17
·3754-3761
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IF 7
Xue Han,Zhaolong Liu,Zhongnan Guo,Xiaojing Feng,Yan Gao,Shifeng Jin,Wenxia Yuan
Chemical intercalation has great potential to realize exotic electrical properties in van der Waals materials. Here we report the Ge intercalation in layered Nb dichalcogenides NbX2 (X = Se and S), which can induce ultrahigh conductivity and novel transport properties. Using the chemical vapor transport method, single crystals of two intercalated materials, namely, Ge0.33NbS2 and Ge0.26NbSe2, were grown. Despite the similar structures with an edge-sharing NbX6 triangular prism, the intercalated Ge shows different configurations in these two compounds, which is ordered in sulfide but disordered in selenide. The measurement of transport properties demonstrated that both Ge0.33NbS2 and Ge0.26NbSe2 are metallic and interestingly the conductivity of Ge0.33NbS2 at 300 K reaches 6.83 × 104 S cm−1, which is higher than those of other metallic transition metal dichalcogenides and even comparable to that of the electrode material Pt. Ge0.33NbS2 also shows high carrier mobility (83.40 cm2 V−1 s−1 at 300 K) and unsaturated linear magnetoresistance, while negative magnetoresistance was observed in Ge0.26NbSe2 below 10 K. The first-principles calculations indicated that the ultrahigh conductivity in Ge0.33NbS2 is ascribed to the non-trivial topological bands near the Fermi surface. Our work highlights the effective regulation of transport properties of van der Waals materials via modulating the band structures by chemical intercalation.
研究领域:
凝聚态物理
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材料科学
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纳米电子学
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DOI
高影响因子
NANOTECHNOLOGY
·
2024
·Vol. 35
·期 42
·425703
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IF 2.9
Yuan-Jun Song,Peng Xia,Xiao-Yang Zhang,Tong Zhang
To address the global energy shortage and mitigate greenhouse gas emissions on a massive scale, it is critical to explore novel and efficient photocatalysts for the utilization of renewable resources. Bi-based metal oxide (BixMOy) semiconductors composed of bismuth, transition metal, and oxygen atoms have demonstrated improved photocatalytic activity and product selectivity. The vast number of element combinations available for BixMOy materials provides a huge compositional space for the rational design and isolation of promising photocatalysts for specific applications. In this study, we have systematically investigated the electronic and optical properties over Bi2O3 and a series of selected BixMOy group materials (BiVO4, BiFeO3, BiCoO3, and BiCrO3) by calculating band structure, basic optical property features, mobility and separation of charge carriers. It is clearly noted that the band gap and band edge position of the BixMOy group materials can be tuned in a wide range in comparison to Bi2O3. Similarly, the light response of BixMOy also can be broadened from the ultraviolet to the visible light region by adjusting the selection of transition metals. Additionally, the analysis of the effective mass of charge carriers of these materials further confirms their possibility in photocatalytic reaction applications because of the appropriate separation efficiency and mobility of carriers. A selection of experimental investigations on the crystal structure, composition, and optical properties of Bi2O3, BiVO4, and BiFeO3 as well as their catalytic performance in the degradation of methylene blue over was also conducted, which agree well with the theoretical predictions.
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Xiaobo Han,Junting Yang,Hengbin Zhao,Qingchun Wang,Fei Ruan,Weixiang Shang,Jinxiao Bao,Yuwei Ma
The construction of a heterojunction with multichannel charge transfer represents an effective strategy for achieving efficient visible light photocatalytic hydrogen production. In this study, the TiO 2 /CdS/Co 2 P ternary photocatalyst was synthesized by stepwise assembly method. The UPS and work function(Φ) results confirmed the band structure and associated band bending of TiO 2 /CdS/Co 2 P, the multichannel electrons transfer from CdS to TiO 2 and CdS to Co 2 P can induce more charge carriers to participate in photocatalytic reaction. Moreover, combine with the results of 3D model charge density and photoelectric performance characterization, proves that the as-prepared ternary photocatalyst accelerates the transfer of photo-generated electrons and reduces the charge recombination rates. According to the Gibbs free energy results, Co as the additional active site is beneficial for hydrogen desorption, thus achieving a high hydrogen production result. Based on the synergistic effects, TiO 2 /55CdS/5.5Co 2 P presented a relatively high hydrogen evolution rate of 250.9 μmol h −1 under the visible light irradiation (λ ≥ 420 nm), which is almost 2 times higher than CdS/5.5Co 2 P (122.8 μmol h −1 ). This work provides theoretical guidance and practical insights for constructing ternary heterojunction structures with central-to-bilateral electron migration to achieve efficient visible-light photocatalytic hydrogen production.
研究领域:
材料科学
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能源科学
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光催化
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产品关联
DOI
高影响因子
Coatings
·
2022
·Vol. 12
·期 4
·439
·
IF 3.236
Xiangduo Cui,Kamale Tuokedaerhan,Haotian Cai,Zhenchuan Lu
Lanthanum-doped HfO2films were deposited on Si by sol–gel technology. The effects of annealing temperature on the optical properties, interface chemistry, and energy band structure of Lanthanum-doped HfO2films have been investigated. The crystallinity and surface morphologies of the films are strongly dependent on the annealing temperature. X-ray diffraction (XRD) analysis showed a monoclinic phase, and there was a tendency to preferentially grow with increasing temperature. The calculated grain sizes ranged from 17.1 to 22.4 nm on average. It was also confirmed from Raman spectroscopy that increasing the annealing temperature can improve the crystallinity of the films. The surface of the film was smooth, and the film had good interfacial contact with the silicon substrate. The band gap increased from 5.53 to 5.91 eV with increasing annealing temperature. The calculated conduction band offset and valence band offset both exceeded 1 eV. In conclusion, smaller grain size, good crystallinity and interfacial contact can be obtained by adjusting the annealing temperature. Higher conduction band and valence band offsets can meet the minimum barrier height requirements of complementary metal oxide semiconductors (CMOS) and have potential applications.Keywords:high-k gate;sol–gel;thin films;annealing temperature
研究领域:
材料科学
·
半导体物理
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DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2023
·
IF 5.4
Xia He,Yuanduo Qu,Siqi Liao,Junkai Wang,Jinling Hu,Lianfeng Duan
A WO 3 /BiVO 4 /CdS-CdSe multistage heterojunction film with a well-matched energy band was constructed to solve the bottleneck problem of photocathodic protection technology not being able to work in round-the-clock continuous operation in practical applications. The WO 3 nanoplate as optoelectronic storage was closely combined with the BiVO 4 , which demonstrated a faster electron transfer rate, to promote photoelectron separation and transfer. Meanwhile, sensitization of CdS-CdSe quantum dots could extend light absorption to the visible region. The photoelectrochemical experiment results showed that the potential of 304 stainless steel as the protected material was negatively shifted to −1.09 V (vs. Ag/AgCl), after coupling with WO 3 /BiVO 4 /CdS-CdSe in 3.5 wt% NaCl solution under simulated sunlight (AM 1.5 G). Notably, the lower potential in this system could also remain for 7 h without the sunlight to achieve round-the-clock photocathodic corrosion protection .
研究领域:
材料科学
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电化学
·
能源科学
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产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Meirong Zhang,Jingyang Wang,Yipin Cheng,Bincheng Ren,Qiuhan Wu,Dong Ma,Honghong Gong,Dengfeng Gao,Zhicheng Zhang
Metallized film capacitors are widely used for their high-power density, high breakdown strength and prominent machining performance. However, achieving high energy density and high discharge efficiency simultaneously in dielectric polymers remains a significant challenge. To address this issue, the novel random copolymer P(MMA-VN) is synthesized via the copolymerization of 2-vinyl naphthalene (2-VN) and methyl methacrylate (MMA). This approach takes advantage of the free volume adjustment capability of rigid conjugated naphthalene rings as side groups, as well as their energy band modulation effect, to enhance energy storage performance. Experimental results reveal that the incorporation of naphthalene rings increases the free volume of the methyl side groups, thereby improving polarization and suppressing relaxation losses. Furthermore, the modification of the energy levels in naphthalene introduces trap energy levels, which enhance carrier trapping ability and effectively reduce leakage loss and the probability of thermal and electrical breakdown. As a result, the P(MMA-VN) with 5 mol% VN unit exhibits outstanding performance, including an ultrahigh energy density (19.3 J cm − 3 ) and remarkable discharging efficiency (>89%) at 800 MV m −1 . This study proposed a novel strategy to reconcile conflict between high energy density and high efficiency in dielectric polymers by regulating free volume and energy level structures.
研究领域:
材料科学
·
能源存储
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DOI
高影响因子
PHYSICA B-CONDENSED MATTER
·
2024
·
IF 2.8
Qihuang Deng,Hong Liu,Yangrui Wang,Maolin Bo,Tielin He,Xue Zhang,Yue Li,Jinliang Zhu,Yue Pei,Yefeng Feng
BaTiO 3 (BTO) based nanoceramics play an important role in electronic devices. Here, we synthesized three BTO-based high-entropy nanoceramics and calculated their band gaps via density functional theory (DFT). Firstly, cubic high-entropy ceramic powders, namely (La 0.2 Ca 0.2 Sr 0.2 Ba 0.2 Li 0.2 )TiO 3 , Ba(Ti 0.2 Sn 0.2 Zr 0.2 Hf 0.2 Nb 0.2 )O 3 and Ba(Ti 0.2 Sn 0.2 Hf 0.2 Zr 0.2 Ta 0.2 )O 3 , were synthesized. Then, composition and morphology of powders was determined. Ultimately, their band gaps were calculated. We clarified the influence of metal co-doping on band gaps. Dirac-cone band-structure was found in Ba(Ti 0.2 Sn 0.2 Zr 0.2 Hf 0.2 Nb 0.2 )O 3 . Compared with BTO (band gap 1.821 eV), BTO-based high-entropy ceramics can have the reduced band gaps (1.549 eV; 0.001 eV; 0 eV) using various co-doping. By high-entropy strategy, conductive ability of BTO-based ceramic is regulated. Experimental results of polymer/ceramic composite dielectrics and theoretical results of ceramics are consistent. Dirac-cone ceramic filler is promising for preparing polymer-based composites for energy storage. This research enables mass preparation of high-entropy ceramic/polymer dielectric composites.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Ying Hao,Zijun Min,Hao Guo,Penghui Shi,Yulin Min,Jinchen Fan,Qunjie Xu
The design of energy band structures and the construction of composite materials are effective ways to improve photocatalytic activity. Hence, Zn x Cd 1−x In 2 S 4 /MoS 2 composites were first prepared in this work by combining Zn x Cd 1−x In 2 S 4 solid solution and MoS 2 nanosheets. The solid solution strategy partly avoided the potential conflicts between visible-light absorption and redox capacity through energy band modulation, and MoS 2 provided more active sites and facilitated the separation of photogenerated carriers. This reasonable structural design improved the visible-light absorption capacity, achieved the appropriate redox potential, promoted carrier separation and transfer during photocatalysis. As-prepared composites of Zn 1/2 Cd 1/2 In 2 S 4 /MoS 2 -18.9% showed excellent photocatalytic hydrogen evolution performance under visible-light illumination, which provided a hydrogen evolution rate of 2255.21 μmol g −1 h −1 with an quantum yield of 19.55% under incident monochromatic light of 420 nm. Zn 1/2 Cd 1/2 In 2 S 4 /MoS 2 composites also displayed long-term stability after five photocatalytic cycles. Finally, the relevant photogenerated charge transfer and catalytic mechanisms of Zn x Cd 1−x In 2 S 4 and Zn 1/2 Cd 1/2 In 2 S 4 /MoS 2 composites were proposed and analyzed.
研究领域:
材料科学
·
能源科学
✓ 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）