JOURNAL OF SOLID STATE CHEMISTRY
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2025
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IF 3.5
Shengming Liu,Yun Zhang,Shihua Ding,Tianxiu Song
V cation was introduced at Nb-site in CoTiNb 2 O 8 for the purpose of tuning the defects concentration. XRD analysis indicated that no secondary phase developed over the whole composition range. The sintering temperature decreased to 1150 °C in current work, compared with pure CoTiNb 2 O 8 ceramic (∼1250 °C). V-introduction inhibited grain growth and benefited grain homogenization. The decreased molecular dielectric polarizability and blue shift of Raman A 1g mode both made lower ε r from 59.2 to 41.8. Based on the X-ray photoelectron spectroscopy (XPS), V doping decreased the oxygen vacancy concentration and tuned the Co valence state. The defects compensation by oxygen and Co vacancies significantly improved Q × f up to 38,012 GHz, accompanied with a 50% rise. The slight increase in τ f was attributed to the Nb-O bond energy reduction. The CoTi(Nb 0.97 V 0.03 ) 2 O 8 had a high ε r of 54.6 with good Q × f of about 38,012 GHz and τ f =96.47 ppm/°C. Enhanced Q × f and low sintering temperature were achieved simultaneously.
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
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IF 4.939
Zhenbao Zhang,Wulan Zhou,Ziwei Yang,Jiahui Jiang,Dengjie Chen,Zongping Shao
In this work, we have demonstrated that by modifying Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) via phosphorous (P) incorporation, the hydrogen evolution reaction (HER) activity was boosted. Such P incorporation was realized through the lattice doping via an in situ method , or bulk/surface co-modification via an ex situ approach. Under optimal conditions, the derived P-doped and bulk/surface-modified BSCF exhibited η 0 of ~205 and ~159 mV, and η 10 of ~333 and ~309 mV in 1.0 M KOH, respectively. Such attractive performance resulted from multiple aspects, including the improved electrochemical active surface area , accelerated charge transfer kinetics, increased high-oxidation state of the Co cation within the Co 3+ /Co 4+ redox couple , and enlarged amount of lattice oxygen species. Moreover, the presence of amorphous regions and structure distortion of P-modified BSCF from the ex situ method greatly facilitated the HER.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Haijuan Zhang,Daqin Guan,Zhiwei Hu,Yu-Cheng Huang,Xinhao Wu,Jie Dai,Chung-Li Dong,Xiaomin Xu,Hong-Ji Lin,Chien-Te Chen,Wei Zhou,Zongping Shao
The development of crystalline-amorphous phase for oxygen-evolving reaction (OER) in water splitting is lagging, and the underlying catalysis mechanism is still unknown. Here, we can facilely construct electrochemistry-induced crystalline-amorphous phase in hybrid La 0.33 SrCo 0.5 Fe 0.5 O x (H-LSCF) nanofibers based on the behavior of high-valence cubic perovskites and Ruddlesden-Popper perovskites after the OER, where such unique combination can be artificially modulated. This nano-sized combination surpasses its pure-phase counterparts and exhibits ultra-low overpotentials of 260 mV and 240 mV at 10 mA cm −2 in 0.1 M and 1 M KOH, respectively, which can be ascribed to their favorable solid-liquid contact, higher Co valence and stronger Co-O covalency to accelerate OER electron transport. The beneficial changes in various surface properties of H-LSCF ensure its stability for 80 h and 60 h in 0.1 M and 1 M KOH, respectively. In -situ 18 O isotope-labelled experiments directly reveal that such combination can trigger exceptional lattice-oxygen activation mechanism.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Zihao Xie,Qian Yang,Xiaomin Xu,Deqing He,Yongning Yi,Hao Qiu,Huangang Shi,Yingping Pang,Wei Wang,Chao Su
The main obstacle in the commercial application of aqueous zinc-air batteries (ZABs) are emerging viable, sustainable, and safe alternatives in electrochemical energy conversion technologies. However, the practical realization of ZABs is impeded by four-electron oxygen evolution (OER) and reduction reactions (ORR) and their sluggish kinetics. Herein, we propose a niobium and fluorine co-doping strategy to regulate in situ Ba and Sr exsolution, inducing the formation of amorphous/crystalline Ba 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ heterointerfaces with an alkali treatment. Associated with the formation of a low valence state of cobalt, an abundant oxygen defects, and amorphous/crystalline feature, the catalyst enables enhanced oxygen binding energy in the OER and ORR activities. The optimized bifunctional perovskite oxide (BSCFeN-F al ) catalysts present an excellent oxygen electrocatalytic activity and stability, with much lower OER and ORR overpotentials than other perovskite oxides in this work and with negligible performance decay in accelerated durability testing. When used as an air-electrode, the BSCFeN-F al demonstrates excellent performance, achieving high power density and remarkable cycling stability. This work highlights the essential function of the heterostructure interface in oxygen electrocatalysis, opening a new avenue to advanced neutral metal-air batteries.
研究领域:
材料科学
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电化学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Xianghui Zeng,Hui Chen,Yongzheng Liu,Wei Fang,Zhaohui Huang,Lei Zhao
Solar-driven CO 2 conversion into fuels using particulate photocatalysts is a promising strategy for mitigating CO 2 emissions with minimal environmental impact. However, the efficiency of CO 2 photoreduction remains limited by the inherent trade-off between light absorption and charge transfer kinetics in single photocatalysts. Herein, we propose an innovative microtubular photocatalytic system consisting of integrated photothermal-photocatalytic materials. The system is based on hollow microtubular g-C 3 N 4 substrates, which are wrapped with thin layers of graphene oxide (GO) acting as photothermal generators, while CoS 2 nanoparticles are embedded between the layers to facilitate charge transfer. The synergistic effects of photon and thermal energy significantly reduce the activation energy by approximately 14 times, thereby promoting oriented electron transfer. Under full spectrum irradiation, the system exhibits superior CO 2 reduction performance, achieving CO and CH 4 yields of 143.73 and 60.27 μmol g −1 , respectively, surpassing the combined contributions from light and heat alone.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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