APPLIED SURFACE SCIENCE
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2022
·
IF 7.392
Zhiyuan Yu,Xin Gu,Yu Gao,Xiaoli Guan,Shuaizhao Jin,Hongjiang Li,Hui Zhang,Xiang Liu
La 0.67 K 0.33- x Sr x MnO 3 thin films were grown on LaAlO 3 ( 010 ) substrates via sol–gel and spin coating methods. The replacement of K ions with Sr ions affected the e g electron bandwidth and concentration of Mn 3+ /Mn 4+ pairs as well as effectively modulated the magnetic/orbital order and lattice structure. Consequently, the ferromagnetic metal to paramagnetic insulation transition was affected, which further optimized the resistivity, temperature coefficient of resistivity ( TCR ), peak TCR temperature ( T K ), and peak resistivity temperature ( T P ). At temperatures below 230 K, temperature-independent scattering and electron-electron scattering were practically not observed in the films. Overall, electrical properties of films improved with an increase in the Sr doping content. The superior La 0.67 K 0.27 Sr 0.06 MnO 3 film exhibited a maximum TCR of 11.88% K −1 (298.3 K), which is approximately 31% higher than that of bulk ceramic with the same composition . The as-developed films exhibit significant potential for application in uncooled infrared bolometers .
研究领域:
材料科学
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物理学
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DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 5
·1783
·
IF 3.4
Chuanqi Liu,Wen Zhang,Dingyu Yang,Haibo Tian,Jun Zhu
The all-inorganic perovskite cesium lead bromine (CsPbBr3) has attracted much attention in the field of X-ray detectors because of its high X-ray absorption coefficient, high carrier collection efficiency, and easy solution preparation. The low-cost anti-solvent method is the main method to prepare CsPbBr3; during this process, solvent volatilization will bring a large number of holes to the film, leading to the increase of defects. Based on the heteroatomic doping strategy, we propose that Pb2+should be partially replaced by Sr2+to prepare leadless all-inorganic perovskite. The introduction of Sr2+promoted the ordered growth of CsPbBr3in the vertical direction, increased the density and uniformity of the thick film, and achieved the goal of CsPbBr3thick film repairing. In addition, the prepared CsPbBr3and CsPbBr3:Sr X-ray detectors were self-powered without external bias, maintaining a stable response during on and off states at different X-ray dose rates. Furthermore, the detector base on 160 µm CsPbBr3:Sr had a sensitivity of 517.02 µC Gyair−1cm−3at zero bias under the dose rate of 0.955 µGy ms−1and it obtained a fast response speed of 0.053–0.148 s. Our work provides a new opportunity to produce cost-effective and highly efficient self-powered perovskite X-ray detectors in a sustainable way.Keywords:X-ray;self-powered detectors;perovskite thick film;Sr-doped CsPbBr3
研究领域:
材料科学
·
物理学
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DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Jinni Shen,Yuhua Zhong,Jianhan Lin,Haifeng Li,Chengwei Qiu,Xu Liu,Xun Wang,Rong Hu,Jinlin Long,Xuxu Wang,Zizhong Zhang
Photocatalytic water splitting on metal oxides often faces oxygen evolution inefficiency, reflecting the complex interplay of its two half-reactions. Strategies like heterojunctions, cocatalyst loading, or noble metal nanoparticles addition have been explored to address this. Using γ-Ga 2 O 3 nanosheets as a model, we uncovered the formation of −O-O- species as the key barrier to stoichiometric splitting. To tackle this, a strategy was devised, Sr-doping to inhibit surface peroxidation. The resultant Sr-doped γ-Ga 2 O 3 (Sr-Ga 2 O 3 ) significantly improved activity and stability, achieving balanced H 2 and O 2 production under 125 W mercury lamp light. Upon further enhancement with Rh/Cr 2 O 3 cocatalyst via photoreduction, the Sr-Ga 2 O 3 /(Rh/Cr 2 O 3 ) composite demonstrated a remarkable 8.7 mmol·g −1 ·h −1 H 2 and 4.4 mmol·g −1 ·h −1 O 2 evolution rate, 8.3 times higher than γ-Ga 2 O 3 alone, with a 34.1 % quantum efficiency under 260 nm light. This represents a record performance for Ga 2 O 3 -based photocatalytic water splitting. Mechanistically, Sr doping alters surface chemistry to favor direct oxygen release. Our study elucidates molecular-level insights into non-stoichiometric splitting mechanisms and offers a potent strategy to boost metal oxide photocatalysts’ water-splitting efficiency.
研究领域:
材料科学
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环境科学
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能源化学
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DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2020
·
IF 2.029
Jianxia Zhang,Li Liu,Chao Sun,Xiaosong Li,Bing Zhao,Xiangnan Ju,Chunxia Tian,Dan Sun,Guijun Nian
The 3D layered α-Fe 2 O 3 microflowers assembled by pure and Sr-doped nanosheets were prepared by hydrothermal and annealing methods. SEM morphological characterization results show that after the introduction of Sr, the microflowers are assembled from more layered nanosheets. XPS indicates that the material can provide more surface oxygen vacancy defects and oxygen adsorption sites, which is beneficial to the improvement of gas sensitivity. The response of 3 wt% Sr-doped α-Fe 2 O 3 with alkaline earth metal element Sr to 100 ppm ethanol (82.1) is 2.37 times that of pure α-Fe 2 O 3 (34.5) to ethanol at low temperature (220 °C).
研究领域:
材料科学
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化学
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DOI
高影响因子
IONICS
·
2025
·
IF 2.6
Wan ZiYi,Lv JingBo,Zhang YaXin
High-entropy perovskite oxides (HEPOs) have emerged as promising electrode materials for supercapacitors. In this study, we successfully synthesized a series of HEPOs La 1- x Sr x (Co 0.2 Mn 0.2 Fe 0.2 Ni 0.2 Cu 0.2 )O 3 , using the sol–gel method. We thoroughly investigated the impact of Sr doping on the electrochemical properties of HEPO materials. Our findings indicate that the incorporation of a small amount of Sr enhances ionic conductivity and promotes the formation of oxygen vacancies and ionic vacancies within the crystal structure. The incorporation of Sr significantly improves the electrochemical performance of HEPOs materials. La 0.9 Sr 0.1 (Co 0.2 Mn 0.2 Fe 0.2 Ni 0.2 Cu 0.2 )O 3 electrode exhibits a maximum specific capacitance of 204.33 F/g at a scan rate of 2 mV/s, a significant increase compared to the undoped La(Co 0.2 Mn 0.2 Fe 0.2 Ni 0.2 Cu 0.2 )O 3 sample. Furthermore, La 0.9 Sr 0.1 (Co 0.2 Mn 0.2 Fe 0.2 Ni 0.2 Cu 0.2 )O 3 electrode exhibits excellent rate performance, maintaining 74% of its capacity when the current density was increased from 1 to 5 A/g. It also exhibits good cycling stability, with nearly no attenuation after 1000 cycles. Therefore, these results underscore the potential of our synthesized high-entropy perovskite oxides as electrode materials for supercapacitors applications.
研究领域:
材料科学
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电化学
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储能技术
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DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 33
·17417-17425
·
IF 7.443
Rui Tang,Longwei Yin
We present a novel Sr-doped TiO2/SrTiO3 nanorod array heterostructure for dye-sensitized solar cells (DSSCs) via a facile two-step hydrothermal process, with a tunable microstructure, optical response and photoelectrical conversion properties. The chemical composition components and microstructures of Sr-doped TiO2/SrTiO3 nanorod array heterostructures are investigated using XRD, XPS, SEM and TEM characterization techniques, respectively. It is shown that the treatment of rutile TiO2 nanorod arrays in Sr(NO3)2 solution results in the self-doping of Sr into the lattice of TiO2 and formation of Sr-doped TiO2/SrTiO3 nanorod array heterostructures, inducing a transition of optical response properties from the ultraviolet region to the visible region. The photogenerated electrons and holes can be effectively separated due to the formation of SrTiO3/Sr-doped TiO2 heterostructures with a uniquely matched band-gap energy structure, resulting in greatly enhanced photoelectric conversion efficiency performance. Electrochemical impedance spectroscopy and photoluminescence results show that the formation of Sr-doped TiO2/SrTiO3 heterostructures can effectively prolong the charge carrier lifetime. The dye loading capacity on the Sr-doped TiO2/SrTiO3 heterostructures can be improved through the functionalization bonding of the hydroxide group on the surface of the electrode material. DSSCs based on the optimized Sr-doped TiO2/SrTiO3 heterostructure photoanode achieve the highest energy conversion efficiency of 4.70% (one sun illumination), nearly 1.5 times higher than the bare rutile TiO2 photoanode (3.10%).
研究领域:
材料科学
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能源科学
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DOI
高影响因子
Sustainable Energy & Fuels
·
2021
·Vol. 5
·期 17
·4295-4310
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IF 6.367
Ke Gao,Xianglei Liu,Tong Wang,Zhonghui Zhu,Ping Li,Hangbin Zheng,Chao Song,Yimin Xuan,Yongliang Li,Yulong Ding
Solar thermochemical CO2-to-fuel conversion via two-step redox cycles is a promising strategy to solve climate change and energy storage challenges simultaneously. However, ideal thermochemical materials possessing moderate operation temperature, high yield, good stability, and rapid kinetics operating under isothermal and near-isothermal conditions are still missing. Here, we propose Sr-doped SmMnO3 for moderate-temperature near-isothermal CO2-to-fuel conversions. A record-high isothermal cycle CO yield (376.1 μmol g−1) at no more than 1300 °C is reported based on Sm0.6Sr0.4MnO3. No obvious decay is observed during 14 cycles although grain sizes have increased to some extent. The weakened Mn–O bond induced by Sr doping helps to create more oxygen vacancies, and thus contributes to enhanced yield of both O2 and CO. The oxidation reaction is fast with a CO yield of 58.6 μmol g−1 in 15 minutes, which is 5.6 times as high as that of CeO2 under the same cycling conditions between 1300 °C and 1000 °C. Detailed kinetics for the oxidation step is unveiled based on the Šesták–Berggren model. In addition, SmxSr1−xMnO3 can capture full-spectrum solar energy with a solar absorptance of more than 86.6% in stark contrast to 13.5% for CeO2, making the required concentration ratio to drive reactions decrease by 33.4%. This work provides new materials for high yield and stable thermochemical CO2-to-fuel conversion under moderate-temperature near-isothermal conditions, and paves the way for the development of CO2 splitting techniques directly driven by low-concentration solar energy with high efficiencies.
研究领域:
材料科学
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可再生能源
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环境科学
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产品关联
DOI
高影响因子
ChemElectroChem
·
2022
·Vol. 9
·期 15
·e202200475
·
IF 4.782
Shu-Fang Li,Jie Zheng,Liang Hu,Yao Ma,Shuang Zhao,Chuan-Hui Zhu,Dong Yan
Graphical Substitute A-site : The effect of Sr-doping on the performance of double perovskite La 2 CoMnO 6 for catalyzing oxygen evolution reaction (OER) has been studied. The A-site partially substituted compounds, which were obtained via a facile sol-gel method, have proved to have better OER performances compared with La 2 CoMnO 6 . A higher content of oxygen vacancies together with the optimized e g orbit filling make contribution to the enhanced OER activity. Developing effective electrocatalysts for oxygen evolution reaction (OER) is crucial for exploring clean fuels. Owing to the flexible structure and unique 3d electron structure, perovskite has been considered as a promising candidate for OER electrocatalyst. Here, we report a range of A-site partially substituted perovskite obtained via a facile sol-gel method, La 2- x Sr x CoMnO 6 ( x =0.2, 0.4, 0.6, 0.8, and 1.0, LSCMO- x ). LSCMO- x has been proved to have better OER performances. Therein, LSCMO-0.8 shows the best OER catalytic performance among these A-site partially substituted perovskites. The OER overpotential of LSCMO-0.8 catalyst is 0.39 V, which is reduced by 80 mV compared to parent perovskite La 2 CoMnO 6 (LCMO, 0.47 V). The experimental studies have shown that LSCMO-0.8 exhibits a higher content of oxygen vacancies compared with LCMO, which may be the factor for the enhanced OER activity. Meanwhile, it is revealed that Sr doped in the A site can efficiently optimize the e g orbit filling. This work manifests that doping Sr into perovskites appropriately is an effective strategy for the improvement of OER activity.
研究领域:
材料科学
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电化学
·
催化
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 52
·期 1
·420-428
·
IF 5.6
Junjie Zang,Laijun Liu,Xiuyun Lei,Congling Yin
A series of Aurivillius-type Sr x Ba 1-x Bi 2 Ta 2 O 9 (SBBT, x = 0–1) ceramics were synthesized using a conventional solid-state reaction route and systematically investigated concerning their crystal structure and ferroelectric properties. High-resolution synchrotron XRD refinements indicate that BaBi 2 Ta 2 O 9 crystallizes in the polar A 2 1 am space group rather than I 4/ mmm , confirming the presence of local non-centrosymmetric distortions. A thermal-driven phase transition from orthorhombic to tetragonal is proposed for BBT. The disorder of Ba/Bi cations occurs in BaBi 2 Ta 2 O 9 . Increasing Sr-doping level tends to decrease the orthorhombic structural distortion of Sr x Ba 1-x Bi 2 Ta 2 O 9 . Raman spectroscopy reveals a redshift of the 840 cm −1 band with increasing Sr content x, consistent with the elongated minimum Ta-O distance within TaO 6 octahedra. The x = 0–0.4 compositions exhibit strong dielectric frequency dispersion, while the x = 0.8–1 samples display frequency-independent sharp dielectric peaks. Low-x compositions exhibit pinched P - E loops characteristic of relaxors, whereas high-x samples display squared P - E loops indicative of normal ferroelectrics. Vogel-Fulcher analysis and a phenomenological model reveal that Sr doping suppresses the dynamics of polar nano-region (PNRs) and increases their size across the x = 0–0.4 sample. These phenomena confirm a transition from relaxor to normal ferroelectricity in the SBBT system introduced by increasing Sr-doping level. This work provides new insights into the structure-property correlations in Aurivillius-phase relaxor ferroelectrics, offering guidance for the high-performance energy-storage materials design.
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DOI
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2022
·
IF 5.443
Ziwei Dong,Tian Xia,Qiang Li,Jingping Wang,Shuang Li,Liping Sun,Lihua Huo,Hui Zhao
Highly active cathode materials are crucial to accelerating the commercialization of intermediate-temperature solid oxide fuel cells (IT-SOFCs). Herein, Sr-doped Pr 0.94 Ba 1- x Sr x Co 2 O 5+ δ (PBS x CO) perovskite oxides are evaluated by experimental and theoretical studies. The phase transformation from tetragonal layered double perovskite to cubic simple perovskite can be identified with increasing the Sr fraction. Benefiting from enhanced electrical conductivity and oxygen surface rate, the PBS x CO catalysts deliver excellent electrochemical performance, as evidenced by symmetrical and completed cells test. Among all compositions, the Pr 0.94 Ba 0.7 Sr 0.3 Co 2 O 5+ δ (PBS0.3CO) cathode has the lowest polarization resistance ( R p ) of 0.031 Ω cm 2 at 700 °C. The PBS0.3CO cathode-based fuel cell produces a peak power density of 1077 mW cm −2 , along with a steady operating for 130 h at 700 °C. From the density functional theoretical (DFT) calculations, it is discovered that stronger Co 3d-O 2p hybridization is recognized in the Sr substituting model compared with undoped one. Furthermore, the decreased free energy for oxygen adsorption may facilitate the oxygen reduction reaction (ORR) kinetics. These findings highlight the origin of optimal ORR activity induced by A-site alkaline earth doping in the perovskite catalysts, endowing the rational design of oxide catalysts.
研究领域:
材料科学
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能源科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Shuangqian Ma,Zhongyang Wang,Lan Yang,Danning He,Ming Yang,Liping Tong,Xiao Zhou,Tongxiang Fan
Ceramics with low solar absorptivity and high infrared emissivity play an important role in radiative cooling applications. BaTiO 3 , for instance, is one promising radiative cooling ceramic, although it has been mainly explored only in electronics. In this work, the solar-reflective and infrared-radiative properties of Sr-doped BaTiO 3 are studied systematically. Ba 1- x Sr x TiO 3 ( x = 0, 0.2, 0.25, 0.3, 0.35) ceramics synthesized by sol-gel method were investigated in terms of their microstructure, phase transition, and optical properties . Increasing infrared emissivity and solar absorptivity were observed with increasing Sr content. The optimized Ba 1- x Sr x TiO 3 achieves solar absorptivity of 0.17 and infrared emissivity of 0.78. The lowest absorptivity-emissivity ratio of 0.24 was observed for Ba 0.8 Sr 0.2 TiO 3 . Meanwhile, the solar absorptivity and infrared emissivity exhibited temperature stabilization, even affront heat-induced phase transition. Finally, the coupling relation between band gap, Ti–O vibration, and optical properties of Ba 1- x Sr x TiO 3 ceramics are clarified, which is promising to improve their radiative cooling performance.
研究领域:
材料科学
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光学
·
热能工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Lanlan Guo,Wei Zhao,Linlin Dong,Xin Shi,Guodong Wang,Rui Li,Jianliang Cao,Xueli Yang,Xiaolian Liu,Yan Wang
The construction of high-performance sensitive materials is a basis for excellent sensors. Among prior SnS 2 -based sensors, high sensing performance often accompanies high operating temperatures or expensive costs, which limits their practical use. Herein, we employed Sr doping and NaBH 4 treatment strategies to increase the S-vacancies content in the SnS 2 microflowers. Particularly, this composite sensitive material shows large specific surface area, low crystallinity and rich S-vacancies content, which enables this sensor excellent sensing properties toward NO 2 , with a response of 4.7 toward 5 ppm NO 2 at 100 °C. In addition, this sensor has a low detection limit for NO 2 as low as 0.2 ppm, which is a lower value compared to many SnS 2 -based NO 2 sensors as reported. XRD, SEM, TEM, EPR and BET characterization combined with density functional theory (DFT) calculations are adopted to illustrate the enhancement mechanism toward NO 2 of the composite sensitive materials fabricated in this work. This study provides new ideas and scientific basis for the construction of metal sulfide based NO 2 sensors, which has important theoretical significance and application value.
研究领域:
材料科学
·
传感器技术
·
计算化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）