Nanomaterials
·
2022
·Vol. 12
·期 6
·1002
·
IF 5.719
Sushu Wan,Yajie Zhu,Daocheng Hong,Yuxi Tian
One of the unique characteristics of semiconductors is the strong dependence of their properties on crystal defects and doping. However, due to the species diversity and low density, it is very difficult to control the type and concentration of the defects. In perovskite materials, crystal defects are randomly formed during the fast crystallization process, causing large heterogeneity of the samples. Here, in this work, we report a controllable method to introduce surface defects on CH3NH3PbI3perovskite materials via the interaction with 1,4-benzoquinone (BQ) molecules on the gas and solid interface. After the adsorption of BQ molecules on the perovskite surface, surface defects can be generated by photoinduced chemical reactions. The concentration of the defects can thus be controlled by precisely regulating the laser irradiation time. The concentration of the defects can be characterized by a gradually decreased PL intensity and lifetime and was found to influence the atmospheric response and the subsequent acetone-induced degradation of the materials. These results demonstrate that crystal defects in perovskite materials can be controllably introduced, which provides a possible way to fully understand the correlation between the nature and chemical structure of these defects.Keywords:lead halide perovskite;polycrystalline thin films;defect modification;defect concentration;optical microscopy
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 33
·期 3
·2210551
·
IF 19.924
Hang Geng,Mengyang Wang,Songfan Wang,Dongxing Kou,Zhengji Zhou,Wenhui Zhou,Yafang Qi,Shengjie Yuan,Litao Han,Yuena Meng,Sixin Wu
Abundant intrinsic defects and defect clusters in Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells lead to severe nonradiative recombination and limited photoelectric performance. Therefore, developing effective method to suppress the detrimental defects is the key to achieve high-efficiency solar cell. Herein, a convenient two-step cooling strategy in selenization process is reported to suppress the Cu Zn and Sn Zn defects and defect clusters synergistically. The results show that rapid cooling during section from selenization temperature to turning temperature can inhibit the volatilization of Sn and restrain the corresponding Sn-related defects, while slow cooling during the subsequent temperature section can reduce the degree of Cu-Zn disorder. Benefitting from the synergistic effect of two-step cooling, a significantly lowered concentration of Sn Zn and Cu Zn defect and their defect clusters [2Cu Zn +Sn Zn ] in absorber is observed, meanwhile, a reduced band tailing effect and promoted carrier collection efficiency of the photovoltaic device is obtained. Finally, a device with improved open-circuit voltage ( V oc ) of 505.5 mV and efficiency of 12.87% is achieved. This study demonstrates the impact of cooling process on defects controlling for the first time and provides a simple and effective new strategy for intrinsic defect control, which may be universal in other inorganic thin film solar cells.
研究领域:
材料科学
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太阳能技术
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半导体物理
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2021
·
IF 4.641
Xinshan Rong,Shixian Zhang,Jian Rong,Jing Wei,Xuchun Qiu,Zhiren Wu
Z-scheme nitrogen-deficient graphitic carbon nitride/ferric oxide (GCN x /FO) photocatalysts were obtained by a one-step calcination method. The number of nitrogen defects was tuned by the application of KOH, while the ferric oxide phase and magnetism was controlled by the usage of ferrous oxalate. Interconversion between the hematite (α) and maghemite (γ) phases of Fe 2 O 3 was analyzed by X-ray diffraction, and magnetism of the GCN x -0.1/FO products provided via vibrating sample magnetometer test. The introduction of nitrogen defects narrowed the bandgap and extended the spectral range of light absorption while improving the ability to capture and activate N 2 effectively. Surface defects were employed as active sites, and the ammonia generation concentration reached approximately 69.7 μmol/L/h by N 2 photofixation under visible light. Due to their ease of synthesis and tuning, high photocatalytic activity, convenient and rapid collection for reuse, and excellent stability, GCN x /FO composited photocatalysts possess vast potential for use in clean ammonia production.
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
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Xinli Ma,Jinxi Zhang,Yang Sun,Chen Wu,Guangyu Geng,Jing Zhang,Enxiu Wu,Linyan Xu,Sen Wu,Xiaodong Hu,Jing Liu
Defect engineering is a promising means to create patterns on two-dimensional (2D) materials to enable unconventional properties. However, defects usually exist abundantly and randomly on 2D materials, which makes it difficult to tune the properties in a controllable manner. Therefore, it is highly desirable to find out the formation mechanism and controllable fabrication method of defects on 2D materials. In this report, we systematically investigated the line defects on monolayer MoS2 formed by introducing oxygen during the CVD growth. The line defects were formed due to the overoxidation of the MoS2 flake along crystal boundaries, which bulged out of the surface and had the same surface potential as the basal plane. Therefore, the MoS2 flake with line defects maintained the optical and electrical integrity but exhibited distinct properties as compared to the pristine one. By controlling the oxygen concentration during CVD growth, the density of the line defects can be precisely controlled to implement controllable property tuning. Moreover, during the transfer process, the MoS2 flake was easily broken along the line defects, which increased the active sites to achieve enhanced hydrogen evolution reaction performance. This work is expected to inspire the development of patterned functional 2D materials by defect engineering.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
RENEWABLE ENERGY
·
2024
·
IF 9
Huajing Zhou,Tiancheng Li,Fawen Zhang,Faze Chen,Zilian Liu,Rongrong Miao,Qingqing Guan,Lingxiang Zhao,Liang He
Intrinsic point defects in metal core-shell materials can regulate electron redistribution, thereby reducing catalytic energy barriers and enhancing their ORR activity. However, their specific contributions to electron transfer and mass transport pathways remain unclear. In this study, defect-rich hollow O Co @Co 3 O 4 nanoparticles were successfully synthesized using ZIF-67(Co) as a sacrificial template through controlled annealing and internal electric field substitution reactions. High-resolution electron microscopy analysis and density functional theory (DFT) calculations co-revealed the growth mechanism of Co and O vacancies, as well as antisite defects. The formation of oxygen vacancies significantly lowered the energy barrier for Co vacancy formation, playing a crucial bridging role in the development of antisite defects. The electric field polarization induced by Co-O atomic displacement resulted in asymmetric charge distribution, optimizing the adsorption of active hydrogen (H*) and oxygen atoms and facilitating the generation and release of reactive oxygen species (ROS). Electrocatalytic experiments demonstrated that under the combined action of singlet oxygen ( 1 O 2 ) and H*, bisphenol A (BPA) can be efficiently degraded. This study successfully bridges the knowledge gap between atomic defects and advanced electrocatalysis, providing a new perspective and insight for the in-depth analysis of the structure-performance relationship of electrocatalyst materials in the future.
研究领域:
材料科学
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环境科学
·
电催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Jianghua Zhao,Yifan Wang,Huai Liu,Rui Zhang,Wenlong Jia,Junhua Zhang,Yong Sun,Lincai Peng
Defect engineering is an effective strategy to enhance the photocatalytic performance of ZnIn2S4 (ZIS), but it remains a formidable challenge to manipulate the cationic defects in the catalyst because of their high formation energies. Herein, dual Zn and In defects have been successfully created in the ZnIn2S4 (ZIS-5) with a facile cetyltrimethylammonium chloride (CTAC)-assisted hydrothermal method. The resulting ZIS-5, rich in cation vacancies, achieved a 3.6-fold higher 2,5-diformylfuran (DFF) yield (92.0%) than the pristine ZIS (25.8%) for the visible-light-driven photocatalytic air-oxidation of 5-hydroxymethylfurfural (HMF). Especially, ZIS-5 delivers a high DFF productivity of 1600 μmol g–1 h–1, significantly surpassing the previously reported catalysts (75–953 μmol g–1 h–1) for the photocatalytic oxidation of HMF to DFF in air. Density functional theory (DFT) simulations revealed that the presence of dual Zn and In defects endows the catalyst with defect states that intersect the Fermi level and lower work function. These enhance the migration and separation of photogenerated carriers in ZIS-5, significantly promoting O2 activation and resulting in the generation of more reactive oxygen species (·O2– and 1O2) for the catalytic oxidation of HMF. This study offers valuable insights for guiding the design of photoredox reaction systems through cationic-defect-engineering strategies, enabling the efficient valorization of biomass-derived platform chemicals.
研究领域:
材料科学
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催化化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Jianghua Yang,Zewen Ji,Shujuan Zhang
The identification of defects and their roles in photocatalytic production of hydrogen peroxide (H2O2) with carbon nitride (CN) is a challenging but important task. Here, a simple route was employed to generate defects in CN by tuning the ratio of the two synthesis precursors: acetylacetone (AcAc) and urea. In this way, a set of modified CNs (AxCN) with dual defects (C doping and surface −OH modification) were successfully fabricated. The one with an AcAc-to-urea ratio (x) of 0.05 showed a photocatalytic H2O2 production rate of 3.6 mmol·g–1·h–1, which was greater than most of the reported CNs. Moreover, the selectivity of H2O2 production was increased from 60% (CN) to 85% (A0.05CN). On the basis of density functional theory and the first-principles calculation, the high performance of A0.05CN was attributed to the synergistic roles of the dual defects in oxygen reduction reactions. The C doping enhanced the anchoring of dioxygen, while the −OH group facilitated the diffusion of charge carriers. The finding here provides an insight into the defect engineering for green generation of H2O2.
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
·
2022
·
IF 16.744
Pengxian Li,Junfeng Ren,Caixia Li,Jiaxu Li,Kai Zhang,Tingting Wu,Bin Li,Lei Wang
Interface engineering is considered as an effective way to inhibit dendrite growth and side reactions in rechargeable zinc ion batteries (ZIBs). Herein, to explore the best treatment routes on how to construct multi-functional protective layers with MOF-based nanomaterials, defect-rich CeO 2 polycrystals are designed with Ce-MOF-808 precursor as ion-selective smart artificial SEI for ZIBs. Interestingly, crystal defects which can provide active sites for Zn 2+ transfer, are introduced to MOF-CeO 2 via pyrolysis. Furthermore, the negative Zeta potential gives high selectivity to cations and shielding effect to anions, inhibiting the side reactions. Besides, MOF-CeO 2 can promote the desolvation process of Zn[(H 2 O) 6 ] 2+ and balance Zn-ion flux by pores. Impressively, synergistic effects on dendrite inhibition by chemical stability, crystal defects, surface charge properties, and hierarchically porous structure are investigated comprehensively. Therefore, MOF-CeO 2 @Zn anode exhibited ultra-stable plating/stripping behavior (more than 3200 h) and high Coulomb efficiency (99.5 % at 2 mA cm −2 ). This multi-functional protective layer also significantly improves the overall performance of Zn||MnVO full battery, with high-capacity retention at 5 A/g after 10,000 cycles.
研究领域:
材料科学
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电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2019
·Vol. 25
·期 55
·12842-12848
·
IF 5.16
Hong Li,Xiao-Fang Jia,Qing Zhao,Ju-Ping Ma,Jian-Dang Liu,Bang-Jiao Ye,Yoshihiro Kuroiwa,Chikako Moriyoshi,Zhi-Yong Li,Qi Liu,Jun-Ying Zhang,Hong-Tao Sun
Graphical Beyond ferroelectricity : The defective [Bi 2 O 2 ] 2+ layers in Aurivillius phases show broadband near-IR luminescence that covers the telecommunication and biological optical windows (see figure). The luminescence was identified to stem from oxygen vacancies and defect complexes. This offers a probe for the examination of defect states in Aurivillius-phase ferroelectrics and possibilities for coupling both physical behaviors. Aurivillius phases have been routinely known as excellent ferroelectrics and have rarely been deemed as materials that luminesce in the near-infrared (NIR) region. Herein, it is shown that the Aurivillius phases can demonstrate broadband NIR luminescence that covers telecommunication and biological optical windows. Experimental characterization of the model system Bi 2.14 Sr 0.75 Ta 2 O 9− x , combined with theoretical calculations, help to establish that the NIR luminescence originates from defective [Bi 2 O 2 ] 2+ layers. Importantly, the generality of this finding is validated based on observations of a rich bank of NIR luminescence characteristics in other Aurivillius phases. This work highlights that incorporating defects into infinitely repeating [Bi 2 O 2 ] 2+ layers can be used as a powerful tool to space-selectively impart unusual luminescence emitters to Aurivillius-phase ferroelectrics, which not only offers an optical probe for the examination of defect states in ferroelectrics, but also provides possibilities for coupling of the ferroelectric property with NIR luminescence.
研究领域:
材料科学
·
光学
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Xingxing Zhou,Minghe Cao,Zhijian Wang,Yun Rao,Qu Luo,Bo Yang,Hua Hao,Zhonghua Yao,Zhiyong Yu,Hanxing Liu
Sr 0.99 Ce 0.01 Ti 1-x O 3 (SCT, x = 0, ± 0.0025, ± 0.0050, 0.0075) ceramics were prepared by solid state reaction methods and sintered in air atmosphere at different temperatures, with a soaking time of 2 h. The dielectric properties of all samples presented excellent temperature independence over a broad temperature range from 25 to 330 ℃ and frequency independence between 10 kHz and 1 MHz. Sr 0.99 Ce 0.01 Ti 0.9925 O 3 (SCT0.9925) ceramics sintered in air atmosphere exhibited a high permittivity (~5400) and a low dielectric loss (~0.01) measured at room temperature and 1 kHz. XPS and complex impedance spectroscopy analysis confirmed that the high permittivity and low dielectric loss were attributed to the fully ionized oxygen vacancies and giant defect-dipoles in Ti-deficient samples. However, a higher dielectric loss of Ti-rich samples is owing to the destruction of giant defect dipoles, in which highly localized electrons were transformed into hopping electrons.
研究领域:
材料科学
·
陶瓷工程
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Pan Li,Shuang Zhu,Haifeng Hu,Lingju Guo,Tao He
Photocatalytic conversion of CO 2 into hydrocarbons by utilization of the solar energy is considered a promising approach to mitigate energy crisis and the environmental issues. Since the defects in a catalyst play an important role in CO 2 reduction, herein, the porous ZnO nanoplates with vacancy defects are synthesized by annealing ZnS(en) 0.5 precursor in air at different temperature. The defect amount in ZnO changes with the annealing temperature, resulting in different photocatalytic activity for CO 2 reduction. The related mechanism has been studied both experimentally and theoretically. Raman spectra and chemical composition of the obtained catalysts are used to determine the defects. Transient techniques are used to investigate the separation of photogenerated charge carriers. CO 2 adsorption capacity for different catalysts is also measured. First-principles calculation is used to study the adsorption and activation of CO 2 on the ZnO surface. We envision that this work may afford an efficient approach to develop the semiconductor photocatalysts with superior activity via defects engineering.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 17
·10260-10268
·
IF 10.7
Yingfen Li,Xingye Chen,Runxi Wang,Nian Zhou,Fang Huang,Jun Zhao,Zhenghua Su,Shuo Chen,Guangxing Liang
In this study, Sb2S3 was introduced into the two-step selenization process to promote bottom grain growth and reduce the surface roughness of the Cu2ZnSn(S,Se)4 light-absorber layer. The introduction of Sb doping in Cu2ZnSn(S,Se)4 can passivate bulk and interface defects and a small conduction band offset (CBO) can be found, which facilitate the improvement of heterojunction carrier transport properties. Similarly, simulations illustrated that Sb doping improved device efficiency by controlling bulk and interface defects and band alignment. This optimized method facilitated the penetration of Sb, resulting in a high-quality CZTSSe absorber layer. Ultimately, the research culminated in a significant enhancement, yielding a solar cell with an impressive efficiency of 13.11%. These findings offer new possibilities for kesterite solar cells and advance the potential of CZTSSe materials in thin film photovoltaic applications.
研究领域:
材料科学
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光伏技术
·
半导体物理
·
薄膜太阳能电池
·
无机功能材料
·
固态电子学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）