JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2025
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IF 6.2
Guodong Hong,Zhenqiang Yu,Dexin Kong,Taoli Huhe,Rui Shan,Haoran Yuan,Yong Chen
Currently, the selection of iron valence states in composite-modified magnetic biochar prepared by co-pyrolysis exhibits a high degree of blindness. Therefore, this study compares the performance of biochar preparation via co-pyrolysis of three different iron valences (Fe 2 + , Fe 3+ , and Fe 6+ ) and potassium oxalate (K 2 C 2 O 4 ) composite modification for tetracycline (TC) removal. The results indicate that the co-activation of potassium oxalate with different iron valences led to the formation of magnetic biochar with varying elemental contents, morphologies, and structures. Batch adsorption experiments demonstrate that KF3-BC has a high tetracycline removal rate over a wide pH range (3 – 11) and at high coexisting ion concentrations (1 – 100 mmol/L). Furthermore, experiments with synthetic swine wastewater in different matrices, the adsorption capacity of KF3-BC for TC (at a concentration of 100 mg/L) exceeds 81.09 mg/g. Additionally, under optimal conditions of 30 °C and pH = 5, the theoretical maximum adsorption capacity (Q max ) for TC is as follows: KF3-BC (236.91 mg/g) > KF6-BC (169.42 mg/g) > KF2-BC (51.34 mg/g) > BC (38.41 mg/g). The adsorption processes of KF2-BC, KF3-BC, and KF6-BC all conform to the Pseudo-second-order and Freundlich models, implying that TC adsorption occurs at the multilayer molecular adsorption on heterogeneous surfaces, primarily driven by chemisorption. The primary adsorption mechanism between KF-BCs and TC molecules is the π–π EDA interactions. Additionally, hydrogen bonding, cation–π complexation, electrostatic interactions, and pore filling also contribute to the adsorption process. This study can assist in selecting the optimal iron source and chemical activator for composite modification of biochar for the adsorption of TC in wastewater.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2025
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IF 8.2
Yudong Zhang,Yuan He,Jun Li,Yang Xu,Yang Yang,Yao Ge,Xun Zhu,Qiang Liao
Optimizing non-noble catalysts for the oxygen reduction reaction (ORR) is crucial for advancing energy storage and conversion technologies. This study investigates the influence of iron valence states and nitrogen precursor contents on the physicochemical properties and electrochemical performance of lignin-based Fe–N–C catalysts. Catalysts are synthesized using different valence iron sources and varying pyrrole contents. The results reveal that iron(II) doping increases microporosity and specific surface area, while iron(III) doping enhances mesoporous and iron contents of the carbon materials. XPS and Raman spectroscopy confirm the successful incorporation of Fe–Nx active sites in the as-prepared LFeIIIPx catalysts. Electrochemical tests demonstrate that LFeIIIP10 exhibits the highest ORR activity, surpassing commercial Pt/C in half-wave potential (E1/2) and limiting current density (JL). The direct formate fuel cell (DFFC) with an LFeIIIP10 air cathode achieves a maximum power density of 24.7 mW cm–2, 32% higher than that with a Pt/C cathode. This study highlights the critical role of tailoring iron valence states and nitrogen levels to develop high ORR performance, cost-effective Fe–N–C catalysts, providing valuable insights for the future design of non-noble metal catalysts in energy applications.
研究领域:
材料科学
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能源技术
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2015
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IF 7.435
Xuning Li,Jiayi Liu,Alexandre I. Rykov,Hongxian Han,Changzi Jin,Xin Liu,Junhu Wang
Two kinds of Fe–Co Prussian blue analogues (Fe–Co PBAs) with different iron valence state, Fe 3 [Co(CN) 6 ] 2 ·12H 2 O and Fe[Co(CN) 6 ]·2H 2 O, were developed as the photo-Fenton catalysts for in-depth investigation of the heterogeneous Fenton reaction mechanism. These two catalysts showed exceptionally high efficiencies for the degradation of Rhodamine B. The efficient redox cycling of iron species in the Fe–Co PBAs photo-Fenton process was deeply explored by Mössbauer spectroscopy. The excellent photo-Fenton activities of these Fe–Co PBAs were ascribed to the existence of highly dispersed water coordinated iron sites and abundant vacancies in the metal-organic-frameworks. Singlet oxygen was identified by radical scavenger experiments and electron paramagnetic resonance spectroscopy, which plays a key role in the photo-Fenton process. Based on these comprehensive experimental results, a novel radical reaction mechanism was proposed. This work not only opens up a new avenue for the application of Fe–Co PBAs, but also gives a deeper insight into the mechanisms of heterogeneous Fenton reactions.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
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2024
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IF 3.9
Ao Wang,Gang Li,Cheng Li,Yujie Tang,Dong Yan,Jian Li,Lichao Jia
Using solid oxide cells to produce and utilize hydrogen is an effective method for addressing energy demands. In this study, vanadium (V) was doped into the B site of the La 0.3 Sr 1.7 Fe 1.3 Ni 0.2 Mo 0.5 O 6-δ double perovskite, which served as the electrode material for symmetrical solid oxide cells. Doping with high-valence V 4+ /V 5+ reduced both the average Fe valence state and the concentration of oxygen vacancies, while simultaneously decreasing the reducing activity of the material and enhancing its stability. After operating at 750 °C and ± 400 mA cm −2 for 150 h, the degradation rates for Cell-LSFNM were 4.56 % and 8.32 %, respectively, while those for Cell-LSFVNM were only 0 % and 3.32 %, respectively. Although V doping slightly diminished the electrochemical performance of the single cell, it significantly improved long-term operational stability in solid oxide fuel/electrolysis cell (SOFC/SOEC) modes.
研究领域:
材料科学
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电化学
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能源材料
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固体氧化物电池
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功能陶瓷
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DOI
高影响因子
Inorganic Chemistry Frontiers
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2020
·Vol. 8
·期 3
·766-776
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IF 5.958
Hua-Shuai Hu,Yang Li,Gao Deng,Ya-Ru Shao,Ke-Xin Li,Chong-Bin Wang,Yuan-Yuan Feng
The development of low-cost, highly active and stable electrocatalysts for the oxygen evolution reaction (OER) is desirable and challenging. In this work, we report nickel foam (NF) supported low-crystalline NiCoFe nanosheet array electrocatalysts derived from NiCo layered double hydroxide via spontaneous cation exchange reaction. Driven by the redox properties of NiCo layered double hydroxide and iron salt precursors, the entire cation exchange reaction process is completed without extra energy input. The chemical composition and catalytic properties of the as-prepared NiCoFe/NF catalysts are strongly dependent on the valence state of the Fe cation in the iron salt precursors. The NiCoFe/NF–FeSO4 catalyst with FeSO4 as the iron salt precursor exhibits satisfactory OER activity with a much lower overpotential of 293 mV to reach a current density of 100 mA cm−2 as compared with NiCoFe/NF–Fe2(SO4)3 (η100 = 333 mV), NiCo/NF (η100 = 425 mV) and commercial RuO2 (η100 = 399 mV) catalysts. Moreover, NiCoFe/NF–FeSO4 also exhibits impressive long-term durability for the OER. The current density remains nearly unchanged during the 95 h of continuous OER test, demonstrating a promising application in actual industrial water electrolysis. These findings indicate that the iron ion valence states in the iron salt precursors have a significant impact on the composition of the catalysts and thus affect their catalytic performances. This work is instructive for the rational design and preparation of highly efficient Earth-abundant electrocatalysts for the OER.
研究领域:
材料科学
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电化学
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DOI
高影响因子
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