Journal of Physical Chemistry C
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2024
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IF 3.3
Xinmiao Gai,Jia Qu,Nan Zhang,Cun You,Fuqing Zhang,Tao Lv,Qiang Tao,Pinwen Zhu,Yan Li,Xin Wang
Bi2Ru2O7 is a weak metal pyrochlore with static disorder from lone-pair electrons. The suppression of static disorder can be observed by in situ Raman spectroscopy, and the abnormal turning point in resistivity can be found at high pressure. X-ray photoelectron spectroscopy (XPS) of bismuth and ruthenium, low-temperature magnetic susceptibility, and magnetization curve were studied, indicating that there were different valence states between bismuth and ruthenium. The in situ high-pressure structure evolution and conductivity in Bi2Ru2O7 were investigated up to 30.4 and 32.7 GPa, respectively. The electronic structure evolution was studied by first-principles calculations up to 30.0 GPa. Some of the Raman peaks related to static disorder were suppressed at around 2.5 and 18.0 GPa, respectively. The [RuO6] octahedron was compressed and distorted with pressure, and the triangular distortion increased in the range of 18.0 and 24.4 GPa. The high-pressure resistivity was measured by the four probe method. It slowly decreased at first and then increased slowly after 2.5 GPa due to the effects of static disorder and the applying pressure. After 18.0 GPa, the resistivity increased rapidly because of the pressure-induced lattice distortion, which led to the weakening of the conductivity of the sample under high pressure. All observations showed that the lattice distortion was influenced by the combined effects of static disorder and pressure before 18.0 GPa, which caused the resistivity to decrease first and then increase. As static disorder is suppressed, Bi2Ru2O7 is close to standard pyrochlore and the conductivity after 18.0 GPa, which is consistent with the theoretical calculation results of band gap.
研究领域:
材料科学
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凝聚态物理
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产品关联
DOI
高影响因子
Small
·
2026
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IF 12.1
Chang Ju,Yuxing Wang,Xinyu Liu,Zijing Xie,Shuijian He,Lin Hu,Xiaolei Huang,Rui Shi,Yana Liu,Jiguang Zhang,Xiaodong Wu,Yunfeng Zhu,Jun Wang
Anion-exchange membrane water electrolysis (AEMWE) represents a prospective technology for hydrogen production but suffers from the lack of efficient oxygen evolution electrocatalysts with high activity, robust stability, and reduced cost. Herein, we report pyrochlore-type bismuth ruthenates (Bi 2 Ru 2 O 7 , BRO) as promising electrocatalysts for oxygen evolution reaction (OER), which exhibits more than 20 times higher OER activity than RuO 2 yet with 48.3 wt.% less Ru content. The high intrinsic activity of BRO originates from the regulated local electronic structure of Ru sites by Bi, optimizing the adsorption behavior of oxygen intermediates and thus boosting the OER kinetics. Moreover, the assembled AEM electrolyzer with BRO as the anode can show a higher energy saving efficiency and a slower activity decay over a 120-h continuous operation in comparison to RuO 2 electrolyzer.
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产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2025
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IF 3.9
Qi Feng,Lu Sun,Penghui Zhu,Xuguang Li,Xiaofeng Miao,Jing Zhao,Mark C. Williams,Chi Zhang
Significant progress has been achieved in enhancing the oxygen evolution reaction (OER) performance of pyrochloric oxides through geometric and electronic structure regulation. However, the issue of A-site cation segregation in these materials remains underexplored. In this study, Bi2Ru2O7, a promising OER electrocatalyst, is synthesized via a sol–gel method, and its surface is modified using l-ascorbic acid to address Bi3+ segregation. This treatment selectively removes the Bi2O3 passivation layer, inducing an amorphous RuOx layer that forms a heterostructure with crystalline Bi2Ru2O7. This engineered structure significantly enhances catalytic performance, reducing the overpotential to 259 mV at 10 mA cm–2 and maintaining stability after continuous operation for >30 h. Comprehensive characterization, electrochemical testing, and density functional theory calculations reveal that the improvements stem from an increased number of oxygen vacancies and enhanced electron transfer. This work underscores the importance of surface engineering to mitigate A-site segregation, providing a new strategy for optimizing Ru-based pyrochlores in energy conversion technologies.
研究领域:
材料科学
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电化学
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能源转换技术
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2025
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IF 7.9
Qi Feng,Lu Sun,Penghui Zhu,Xiaofeng Miao,Xuguang Li,Jing Zhao,Fuqin Deng,Yajun Wang,Zheng Liu,Guangxia Wang
Efficient and durable electrocatalysts for the oxygen evolution reaction (OER) are vital for advancing renewable energy technologies, particularly in water-splitting systems. Herein, we report a novel surface engineering strategy to enhance the OER performance of Bi 2 Ru 2 O 7 (BRO) pyrochlore oxide by constructing amorphous/crystalline heterostructures. Using four surface treatment agents—nitric acid, hydrogen peroxide, vitamin C, and sodium borohydride—we successfully induced an amorphous RuOx layer on crystalline BRO, significantly increasing specific surface area, oxygen vacancies, and active sites. Among these, vitamin C-treated BRO (BRO-VC) exhibited exceptional OER activity, achieving a low overpotential of 297 mV at 10 mA cm −2 in 1 M KOH, outperforming untreated BRO (349 mV), other treated variants, and commercial RuO 2 (410 mV). Density functional theory (DFT) calculations reveal that the RuO x /BRO heterostructure shifts the d-band center, optimizing adsorption energies of OER intermediates and reducing overpotential. This work demonstrates that tailoring amorphous/crystalline interfaces via surface treatment offers a powerful approach to designing high-performance OER catalysts, providing critical insights into structural engineering for electrocatalytic applications.
研究领域:
材料科学
·
电化学
✓ 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）