JOURNAL OF MATERIALS SCIENCE
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2022
·Vol. 57
·期 16
·7896-7908
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IF 4.682
Xu Tianye,Lu Shun,Wang Yajie,Gan Xiaoyan,Guo Liling,Liu Hanxing
Two-dimensional (2D) perovskite formed by introducing various organic spacer cations into 3D perovskite is considered to be one of the most effective methods to improve the humidity stability of perovskite materials. In order to solve the phase inhomogeneity and phase distribution nonuniformity of two-dimensional perovskites, additive engineering technique is widely used during their fabrication processes. Although many additives are proved to be effective in improving the quality of perovskite films, the mechanism of additive engineering has not been fully understood. In our work, we prepare 2D Ruddlesden–Popper perovskites based on 4-bromophenylethylammonium (BPEA) using a new additive of ionic liquids MAAc (methylammonium acetate). The (BPEA) 2 (MA) 4 Pb 5 I 16 perovskite prepared with the assistance of MAAc exhibits a stable photoelectric conversion efficiency (PCE) of 8.47%, which is much higher than the one without MAAc additive (4.79%). Besides a nearly tenfold increase in electron mobility, the unencapsulated (BPEA) 2 (MA) 4 Pb 5 I 16 -based device with MAAc additive remains 88% of its initial efficiency after 960 h exposure to air with a humidity of 20 ± 5% at room temperature, while the device without additive decreases to 63% of its initial efficiency. Meanwhile, the interactions between PbI 2 and MAAc at different temperatures and molar ratios are investigated and the formation mechanism of 2D perovskites in the presence of MAAc is proposed. It is found that an intermediate perovskite with distorted [PbI 6− x Ac x ] 4− octahedron is formed with the addition of MAAc, making the quality and photoelectric properties of the resultant films greatly enhanced.
研究领域:
材料科学
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能源技术
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光伏器件
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Shu-Fang Li,Bao-Qin Zhang,Yu-Qing Wang,Dong Yan
Prior studies have demonstrated that Ruddlesden–Popper (RP) type perovskite oxides exhibit promising electrocatalytic properties for oxygen evolution reaction (OER). However, the limited electrocatalytic activity has impeded their widespread utilization. The incorporation of heteroatoms into the Ruddlesden–Popper type structure has been identified as an effective strategy to enhance the electrocatalytic performance. This research presents the systematic design and synthesis of RP type perovskite oxide LaSrFeO 4 (LSFO), followed by the optimization of electrocatalytic activity through Ni substitution at the Fe site of SLFO to create LaSrFe 1- x Ni x O 4 (LSFNO- x , x = 0.2, 0.4, and 0.5). Therein, the LSFNO-0.4 sample achieved a current density of 10 mA·cm −2 with an overpotential of only 340 mV. Additionally, it displayed exceptional stability over 120 h in a 1.0 M KOH solution. Both experimental and theoretical studies suggest that the addition of Ni cation increases the Fe − O covalency, and impacts the morphology and surface electron density of LSFO. This substitution results in a greater electrochemically active surface area, improved electron transfer, and optimization of hydrogen/water absorption free energy. This study presents a successful approach for enhancing the OER performance of Ruddlesden–Popper LSFO through the deliberate control of Fe − O covalent bonding.
研究领域:
材料科学
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电化学
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催化
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
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2017
·
IF 4.798
Hongmei Chen,Xiaoqin Sun,Xiaoxiang Xu
Here we report two Ruddlesden-Popper type ferrite perovskites (SrO)(LaFeO 3 ) n (n = 1 and 2) which demonstrate p-type semiconductivity. Their crystal structure, optical absorption and other physicochemical properties have been systematically explored. Our results show that both ferrites crystallize in tetragonal symmetry with structural lamination along c axis. Efficient photocatalytic hydrogen production has been achieved for both samples under full range and visible light illumination. Better performance is noticed for LaSrFeO 4 with apparent quantum efficiency approaches 0.31% and 0.19% under full range and visible light illumination, respectively. The p-type semiconductivity is verified by their cathodic photocurrent as well as negative Mott-Schottky slop during Photoelectrochemical measurement. The relative lower activity for La 2 SrFe 2 O 7 compared to LaSrFeO 4 is likely due to its higher defect concentration which facilitates charge recombination. Both compounds exhibit anisotropic phenomenon for charge migrations according to theoretical calculations. Their p-type semiconductivity, strong visible light absorption, chemical inertness and high abundance of constituent elements signify promising applications in the field of solar energy conversion and optoelectronics.
研究领域:
材料科学
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能源转换技术
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光电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Guohong Pan,Yanzhu Deng,Ling Zhao,Huanwen Wang,Rui Wang,Jun Jin,Yansheng Gong,Beibei He
Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the prerequisite reactions in rechargeable zinc-air batteries (ZABs), but their kinetics are usually slow. In order to develop energy-efficient ZABs, it is highly desirable to pursue bifunctional catalysts with the accelerated reaction kinetics and the reduced overpotentials. Transition metal oxides are expected as promising alternatives to replace noble metal-based catalysts, but their catalytic activities are still far from desirable. Herein, we propose a modified layer of Ruddlesden-Popper perovskite (Pr,Sr) 2 Ni 0.5 Co 0.5 O 4-δ (RP-PSNC) on the perovskite PrNi 0.5 Co 0.5 O 3-δ (P-PNC) nanofiber by a simple impregnation method, receiving a (Pr,Sr) 2 Ni 0.5 Co 0.5 O 4-δ / PrNi 0.5 Co 0.5 O 3-δ (RP-PSNC/P-PNC) heterostructured nanofibers. The RP-PSNC/P-PNC hybrid catalyst exhibits a small overpotential and an excellent stability due to the large number of vacancies in the two-phase interface. The RP-PSNC/P-PNC-based liquid rechargeable ZAB reaches a power density of 145 mW cm −2 , and 230 h of long-term cycle performance. When assembled into flexible ZABs, it can also reach a power density of 51 mW cm −2 and a stable open circuit voltage (∼1.35 V) for 44 h. These results indicate that the bifunctional electrocatalyst of heterostructured RP-PSNC/P-PNC provides a new path for the modification of perovskites through multi-phase catalysts system, and has great potential in rechargeable ZABs and other energy conversion devices.
研究领域:
材料科学
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能源化学
✓ 已验证
DOI
高影响因子
Small
·
2024
·
IF 13
Lubing Chen,Guanchao Wang,Kazuaki Toyoura,Donglin Han
Oxygen-excess La 2 NiO 4+ δ (LNO) conducts oxide ions, electron holes, and hydroxide ions simultaneously on exposing to wet oxygen, exhibiting the potential as a cathode material in protonic ceramic fuel cells. Since the incorporation of protons in oxygen-excess LNO is via the hydration reaction assisted by interstitial oxide ions, in this work, the concentration of interstitial oxide ions is reduced and increased by substituting Ni with Cu and Co, respectively. A higher concentration of interstitial oxide ions leads to a high proton concentration, indicating the predominant role of interstitial oxide ions in the hydration reaction, different from that in the oxygen-deficient oxides, where protons are introduced by dissociative absorption of water molecules by oxygen vacancies. The theoretical calculation indicates that protons in Co-doped LNO prefer to locate between the interstitial oxide ions and unshared apical oxide ions. A trapping effect is found between protons and the oxide ions near Cu, leading to decreased proton mobility. Protonic conductivity at 400–575 °C is then directly measured by a Hebb–Wagner direct current polarization method with La 0.99 Ca 0.01 NbO 4− δ as the blocking electrode, enabling the observation that Co-doped LNO has the highest protonic conductivity among the samples studied in this work.
研究领域:
材料科学
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燃料电池研究
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产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Ting Chen,Guangjun Zhang,Kui Liu,Chenxiao Wang,Guozhu Zheng,Zuzhi Huang,Ning Sun,Lang Xu,Juan Zhou,Yucun Zhou,Shaorong Wang
Reversible proton-conducting solid oxide cells (R-PSOCs) are considered to be one of the most promising devices for efficient power generation and hydrogen production. However, the requirement of high catalytic activity for fast oxygen reduction/evolution reaction (ORR/OER) and durability under high steam concentration of air electrode materials remains the major challenge for the practical application of R-PSOCs. Here, a series of cobalt-free Ruddlesden–Popper perovskite of Nd 0.8 Sr 1.2 Ni 1-x Fe x O 4±δ are reported with mixed conductivity for enhanced ORR/OER kinetics. The R-PSOCs with an optimal Nd 0.8 Sr 1.2 Ni 0.7 Fe 0.3 O 4±δ air electrode show a high peak power density of 1.28 W cm −2 in the fuel cell mode and a promising current density of 3.24 A cm −2 at 1.3 V in the electrolysis cell mode at 700 °C. In addition, the R-PSOCs show favorable stability under the fuel cell, electrolysis, and reversible modes for hundreds of hours. This work demonstrates that the Ruddlesden–Popper materials can be utilized as suitable air electrodes for R-PSOCs.
研究领域:
材料科学
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能源技术
✓ 已验证
DOI
高影响因子
ACS Nano
·
2025
·
IF 16
Hui Zeng,Yao Wen,Yangyuan Tu,Hao Wang,Ziren Xiong,Xiaolin Zhang,Hao Zhu,Jiaqing Qi,Ruiqing Cheng,Lei Yin,Chao Jiang,Jun He
Ferroelectric tunnel junctions (FTJs) based on ferroelectric switching and quantum tunneling effects with thickness down to a few unit cells have been explored for applications of two-dimensional (2D) electronic devices in data storage and neural networks. As a key performance indicator, the enhanced tunneling electrosistance (TER) ratio provides a broader dynamic range for precise modulation of synaptic weights, improving the stability and accuracy of neural networks. Herein, we report an observation of pronounced enhancement in the TER ratio by over 4 orders of magnitude through the fabrication of large-scale heterostructures combining bismuth ferrite with two-dimensional Ruddlesden–Popper oxide Bi2FeO4. The significant difference in Schottky barrier height between Bi2FeO4 and electrodes leads to a remarkable TER value of 7.8 × 106. Moreover, benefiting from the enhanced conductance contrast between the high resistance state (HRS) and low resistance state (LRS), we demonstrate image recognition and dehaze processing using artificial neural synapses based on these FTJs. These results indicate that giant barrier height modulation can be realized through 2D Ruddlesden–Popper oxides, providing a facile technique for high-density in-memory computing applications.
研究领域:
材料科学
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纳米电子学
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类脑计算
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铁电材料
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量子器件
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
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2024
·
IF 5.1
Zhiyuan Pan,Sihan Feng,Fan Li,Xuejiao Wang,Qi Zhu,Ji-Guang Li
Near-infrared phosphor converted light-emitting diodes (NIR pc-LEDs), as a state-of-the-art type of NIR sources, are finding multifaceted applications, where phosphor is a crucial component. In hope to provide new choices for NIR lighting, we synthesized in this work the two series of Ruddlesden -Popper type layered perovskite phosphors of SrLa 2 Al 2- x O 7 : x Cr 3+ ( x = 0–0.02) and SrLa 2- y Gd y Al 1.984 O 7 :0.016Cr 3+ ( y = 0–2), followed by detailed structure and luminescence investigation. SrLa 2 Al 2- x O 7 : x Cr 3+ was found to emit ∼700–800 nm NIR light under UV excitation and be able to maintain ∼54.3 % of its room temperature intensity at 423 K, which is remarkably higher than those (∼25–30 %@423 K) of the Mn 4+ activated perovskite NIR phosphors. Luminescence regulation was achieved by substituting La 3+ with Gd 3+ , and it was revealed that Gd 3+ may act as a sensitizer to significantly enhance Cr 3+ luminescence (∼346 % at 77 K) through Gd 3+ → Cr 3+ energy transfer, which was confirmed by spectral and fluorescence lifetime analysis. The observed spectral features and the influence of Gd 3+ were rationalized by considering crystal structure, local coordination, and crystal field. Finally, an NIR pc-LED device showing strong ∼700–900 nm luminescence was fabricated to show potential application of the phosphor in night vision and plant lighting.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
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2021
·
IF 4.126
Tong Guo,Cheng Tian,Shiqi Zhao,Zihao Chu,Jingli Ma,Ying Li,Zhifeng Shi,Guangzhao Ran
Two-dimensional (2D) Ruddlesden–Popper (RP) perovskites are excellent optoelectronic materials due to their natural quantum well structure and enhanced environmental stability. However, the growth of their large-area high-quality thin films is still fundamentally challenging. Herein, a novel gravity-guided growth method is proposed to grow a wafer-scale (∼8 cm2) (PEA)2PbBr4 thin films (∼μm) with a centimeter-scale crystal domain on an inclined substrate. A model is established to elucidate the role of gravity in the growth process. It can be concluded that the tip of the precursor solution on an inclined substrate should be preferentially induced to nucleate and crystallize. In addition, the crystallization growth is directionally guided and its velocity increases as the rear contact angle decreases. Experimentally, the controllable inclination angles can optimize the quality and thickness of the films. Moreover, the arrayed photodetectors based on the resulting (PEA)2PbBr4 thin films have been demonstrated to have an extremely dark current of 10–12 A and good environmental stability. After 100 days of storage in the atmosphere for the unencapsulated samples, there is only a small photocurrent degradation of 18%. This work provides a promising solution for scalable fabrication of the large-area high-quality 2D perovskite thin films that can serve as a good candidate for stable photodetectors.
研究领域:
材料科学
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光电子学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Liping Fang,Kai Wang,Chen Han,Xinyong Li,Pei Li,Jieshan Qiu,Shaomin Liu
Piezocatalysis utilizes mechanical energy to achieve the required charge separation for redox reactions, a promising method for clean H 2 O 2 production. However, the efficiency of conventional piezocatalysts is limited by the undesirable low piezoelectricity. Herein, novel piezocatalysts composed of La, Sr, Co (Fe) in simple single perovskites (La 0.5 Sr 0.5 FeO 3-δ and La 0.5 Sr 0.5 CoO 3-δ ) and Ruddlesden-Popper (R-P) type perovskites (LaSrFeO 4-δ and LaSrCoO 4-δ ) are developed for piezocatalytic H 2 O 2 production. Results indicate that Fe-containing catalysts outperform Co-containing counterparts and the unique R-P perovskite oxides demonstrate significantly enhanced piezocatalytic performance than the corresponding single perovskites. For example, via piezocatalysis, the LaSrFeO 4-δ exhibits H 2 O 2 yields of 548 (in 10 % ethanol) and 247 µmol g −1 h −1 (without sacrificial agent), improved by a factor of 1.14, 4.94, or 21.73 compared to La 0.5 Sr 0.5 FeO 3-δ , LaSrCoO 4-δ , or La 0.5 Sr 0.5 CoO 3-δ , respectively. The piezoelectricity is an overwhelming factor in determining the H 2 O 2 generation. Furthermore, the piezoelectricity and oxygen vacancy (OV) content is well correlated. The R-P phase with lower OV exhibits a higher piezoelectricity because of the eliminated pining effect to the polarization domain reversion. Mechanism exploration suggests that H 2 O 2 formation stems from the efficient O 2 reduction via a 2-electron transferring pathway, during which the piezoelectric polarization drives the charge separation and transportation, favoring the redox reactions.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Zhuangzhuang Zhang,Shining Geng,Jiaoxia Zhang,Zilong Zhang,Qiu Xiong,Lusheng Liang,Ruixiang Mi,Zewen Xiao,Rosario Scopelliti,Peng Gao
We present a homologous series (CH3(NH2)2)2PbX4 (X = Cl, Br, I) of the Ruddlesden–Popper two-dimensional (2D) perovskite series. The new A-site cation (methyl hydrazinium, MHy) stemming from an atomic permutation of formamidine shows unique hydrogen-bond-stabilized 2D structures contrasting ethyl amine (CH3CH2NH3) and formamidine (NHCHNH2) as revealed by single-crystal X-ray diffraction. The subtle manipulation of the tolerance factor leads to (CH3(NH2)2)2PbX4 with the smallest interlayer spacing among the reported R–P 2D perovskites. A combined density functional theory calculation and experimental study assist in interpreting these disparate (electronic) structures/properties brought by similar cations. First-principles calculations also confirm the direct bandgap nature of (CH3(NH2)2)2PbI4 with wide valence and conduction bandwidths. After studying different colloidal behavior in the common polar solvents, we continued with the characterization based on the thin film samples. The homologous series (CH3(NH2)2)(CH3NH3)nPbnI3n+1 (n = 1, 2, 3, 4) multidimensional (MD) perovskite films show a characteristic decrease of the bandgap as n increases. The potential of these MD perovskites toward planar junction solar cell applications was assessed, and an initial power conversion efficiency of 5.83% was obtained from the (CH3(NH2)2)2(CH3NH3)3Pb4I13 perovskite, with reasonable stability after aging for 1200 h. This new cation provides new chances for many more homologous 2D halide perovskites for solid-state photovoltaics and other applications.
研究领域:
材料科学
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化学
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物理
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太阳能
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2024
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IF 8.1
Zhengfeng Wang,Xiaoyun Miao,Xingzhi Zhu,Shihang Guo,Donglin Han,Xiaofeng Ye,Zhaoyin Wen
The Ln 2 NiO 4+δ compound (Ln = La, Pr, Nd) finds extensive use as a cobalt-free oxygen electrode material in protonic ceramic electrolysis cells (PCECs) owing to its unique RP-type structure and remarkable catalytic activity . In this study, Cu and Zn co-substitution is employed to fabricate a series of materials, within the La 1 · 2 Sr 0 · 8 Ni 0.5 Cu x Zn 0.5-x O 4+δ system (x = 0.1, 0.2, 0.3, 0.4, denote as LSNCZ14, LSNCZ23, LSNCZ32, and LSNCZ41), and the crystal structure, conductivity, proton absorption and electrochemical properties are comprehensively investigated. The LSNCZ41 exhibits the lowest polarization resistance of 0.83 Ω cm 2 at 600 °C in the symmetric cell. The PCEC single cell incorporating the LSNCZ41 air electrode demonstrates a high electrolysis current density of 1.5 A cm −2 (1.3 V) at 600 °C under 60 % humidity in air, furthermore, negligible degradation is observed under this high current density during electrolysis for over 250 h. These results indicate that LSNCZ41 possesses a higher concentration of interstitial oxygen ions and superior proton absorption capacity , significantly expediting the oxygen reduction reaction (ORR) and ionic transport processes. This material can be considered as a promising candidate for the PCEC air electrodes due to its superior stability in air with high steam content.
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）