INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2023
·
IF 4.6
Yuping Gai,Junbo Hu,Wei Deng,Wenshuo Xie,Xiang Li,Jingjing Zhang,Dewu Long,Shanlin Qiao,Fei Jiang
Summary. Electrochemical water decomposition as a crucial approach for the gradual growth of renewable energy has attracted extensive attention. Metal-organic frameworks (MOFs) which benefit from ultra-high specific surface area, controllable nanostructures, and excellent porosity have been widely used as high activity catalyst for the decomposition of water by electrochemical means. Herein, the composition and morphology of metal–organic framework nanoclusters with bimetallic Co/Fe-incorporated PTA/FDA nanoclusters is designed for efficient and durable OER electrocatalysts, including CoFe-BTC/PTA, CoFe-BTC/FDA, and CoFe-PTA/FDA. The crystal structure of MOF materials is composed of alternating organic hydrocarbon BTC, PTA, or FDA and inorganic metal oxide layer. Co and Fe interact as central atoms, joining BTC, PTA, or FDA ligands to form a highly symmetric MOF structure. The electronic structures and active sites of various metals are different, and the insertion of iron atoms plays a certain role in the regulation of their electronic structures. CoFe-PTA/FDA shows significant OER overpotential (1.525 V vs. RHE) reached 10 mA cm-2, with 62.85 mV dec-1 for Tafel slope and pretty conspicuous stability (72 hours of continuous testing). The DFT calculation results show coordination unsaturated metal atom is the primary active center of these electrocatalytic reaction, and the coupling effect caused by adding Fe is the key to adjust the electrocatalytic activity.
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高影响因子
CARBON
·
2022
·
IF 11.307
Fangqian Han,Liu Qian,Qianru Wu,Dong Li,Shulan Hao,Lihu Feng,Liantao Xin,Tao Yang,Jin Zhang,Maoshuai He
A SiC supported iron (Fe–SiC) catalyst was developed for chemical vapor deposition (CVD) growth of carbon nanotubes. Using CO as the carbon source, sole Fe–SiC catalyst was mostly inactive for synthesizing carbon nanotubes and only trace amount of carbon deposits was produced. In contrast, the powder Fe–SiC catalyst could be activated by pressing them onto a flat SiO 2 substrate or by mixing them with porous MgO powders. Particularly, efficient growth of single-walled carbon nanotubes (SWNTs) was achieved on porous MgO promoted Fe–SiC catalyst, and predominant synthesis of (6, 5) SWNTs was realized at a reaction temperature of 650 °C. Systematic characterizations revealed that the reducibility of the Fe–SiC catalyst was enhanced by the physical contact with oxide support, which promotes the formation of small active Fe nanoparticles for the subsequent SWNT nucleation and growth. This work not only deepens our understandings to the catalyst activation mechanisms, but also helps design composite catalyst for synthesizing SWNTs.
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高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 7
·1847
·
IF 5.076
Yan Ma,Yujie Miao,Guomei Mu,Dunmin Lin,Chenggang Xu,Wen Zeng,Fengyu Xie
Great expectations have been held for the electrochemical splitting of water for producing hydrogen as a significant carbon-neutral technology aimed at solving the global energy crisis and greenhouse gas issues. However, the oxygen evolution reaction (OER) process must be energetically catalyzed over a long period at high output, leading to challenges for efficient and stable processing of electrodes for practical purposes. Here, we first prepared Fe-MOF nanosheet arrays on nickel foam via rare-earth erbium doping (Er0.4Fe-MOF/NF) and applied them as OER electrocatalysts. The Er0.4Fe-MOF/NF exhibited wonderful OER performance and could yield a 100 mA cm−2current density at an overpotential of 248 mV with outstanding long-term electrochemical durability for at least 100 h. At large current densities of 500 and 1000 mA cm−2, overpotentials of only 297 mV and 326 mV were achieved, respectively, revealing its potential in industrial applications. The enhancement was attributed to the synergistic effects of the Fe and Er sites, with Er playing a supporting role in the engineering of the electronic states of the Fe sites to endow them with enhanced OER activity. Such a strategy of engineering the OER activity of Fe-MOF via rare-earth ion doping paves a new avenue to design other MOF catalysts for industrial OER applications.Keywords:rare-earth doping;MOFs;large current;electronic structure
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PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 15
·3874-3884
·
IF 7.779
Mengchen Song,Liuting Zhang,Zhendong Yao,Jiaguang Zheng,Danhong Shang,Lixin Chen,Hong Li
Maintaining fast hydrogen storage kinetics is a key challenge for the practical application of MgH2. To address this challenge, understanding the mechanism of kinetics that declines during cycling is crucial but it has not been systematically investigated to date. In this paper, three different Fe nanocatalysts were synthesized and then doped into MgH2 to form new composites. The MgH2-Fe composite had significantly reduced operating temperatures and activation energy compared to that of undoped MgH2. During cycling, a capacity retention of 93.4% was obtained after the 20th cycle. For a better understanding of the declining performance, prolonged incubation was intentionally performed. Grain growth was found in MgH2 and the Fe nanocatalysts, which was directly responsible for capacity loss and kinetic degradation. These findings provide fundamental insights to facilitate designing and preparing catalytic hydrogen storage systems with superior cycling performance.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Hongbin Wang,Jiewen Deng,Xiaohui Lu,Li Wan,Jin Huang,Yiqing Liu
The improvement on diclofenac (DCF) degradation by Fe(II)-activated persulfate (PS) combined with bisulfite (BS) was investigated. It was observed that the introduction of BS in Fe(II)/PS process enhanced the circulation of Fe(III/II) and kept Fe(II) at a high concentration, resulting a rapid and continuous DCF degradation. The initial pH, reagent dosages and reaction temperature played important roles on DCF removal in BS/Fe(II)/PS process. The main iron species in this system were FeHSO 3 + , Fe 2+ and FeOHSO 3 H + , and their variation trends were calculated by the software of MINITEQ 3.1. Based on the alcohols quenching experiments, SO 4 − was confirmed to be the prominent reactive radical for DCF oxidation in BS/Fe(II)/PS process. Moreover, the probable DCF degradation mechanism was proposed based on the detected intermediate products and density functional theory (DFT) calculation. The BS/Fe(II)/PS system presented a synergistic effect for rapid and steady DCF degradation through the occurred cycle of Fe(II/III) (i.e., oxidation of Fe(II) by PS and then reduction of Fe(III) by BS) and solved the drawbacks of slow initial reaction of Fe(II)/BS and weak durability of Fe(II)/PS. This study could provide an effective and environmentally friendly approach to sewage treatment.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Mingyu Li,Chaoqun Li,Zhao Chunrui,Tianren Li,Jingjing Jiang,Zhonghui Han,Chongjun Zhang,Haoran Sun,Shuangshi Dong
Fe-based metal organic framework with high active site exposure, wide light absorption and fast H 2 O 2 activation are pivotal for photo-Fenton degradation of contaminants. However, insufficient active site exposure, weak visible light adsorption and low charge transfer efficiency in iron-oxo clusters usually lead to the slow Fe(II)/Fe(III) cycle. In this study, we develop a novel citric acid (CA)-modified MIL-88A(Fe) strategy to boost photo-Fenton efficiency by accelerating Fe(II)/Fe(III) cycle for emerging contaminants removal. Relationship between CA coordination mode and photo-Fenton performance was studied by using methylene blue (MB) and carbamazepine (CBZ) as model contaminants. It was found that the degradation rate constants of MIL-88A(Fe)-CA-3 were 6.5 and 2.6 times higher than those in the pristine MIL-88A(Fe) for MB and CBZ degradation, respectively. The optimized MIL-88A(Fe)-CA-3 also exhibited good recyclability, enabling multiple cycles in photo-Fenton reaction. The results of experimental characterizations and density functional theory calculations demonstrated that ligand substitution was conductive to active site exposure, visible light absorption, charge carrier transfer and Fe 2+ /Fe 3+ redox cycle, which are responsible for an improved photo-Fenton performance.
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高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2022
·
IF 4.119
Jingjing Sun,Shangqing Chen,Junfeng Wang,Yi Nie
The reduce of the silicon concentration to low level (<5 mg·L −1 ) from the reverse osmosis brine wastewater is challenging and desirable for the maintain the membrane life and performance, as well as the wastewater treatment costs. This work focuses on the removal of silicon from the reverse osmosis brine wastewater by adding FeCl 3 into the plant wastewater for simultaneous Fe(OH) 3 formation and silicon adsorption. The effects of pH, FeCl 3 dosing concentration, reaction time, and temperature on the silicon removal ratio were investigated. It was demonstrated that the silicon removal ratio could reach up to 94% and its residual concentration was 3.2 mg·L −1 , which met the require of water quality in the reverse osmosis system. These results showed that Fe(OH) 3 could effectively be formed by adding FeCl 3 and realize the efficient silicon removal from the reverse osmosis brine wastewater, even when chloride ion (Cl - ), sulfate anion ( S O 4 2 - ) and nitrate ion ( N O 3 - ) were present. Moreover, the adsorption thermodynamics, kinetics and isotherms during the process of the adsorption of silicon from the wastewater by Fe(OH) 3 were studied. The calculated adsorption capacity of silicon could reach 612.74 mg·g −1 , which was much larger than those of reported adsorbents. These results showed that the silicon removal process was spontaneously exothermic and mainly controlled by the physical adsorption and the monomolecular layer adsorption. This simple and cost-effective method could be used for the silicon removal from different kinds of Si-containing wastewater.
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高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2018
·Vol. 33
·期 1
·e4580
·
IF 3.581
Hongxu Guo,Baitong Niu,Xuemin Wu,Yi Zhang,Shaoming Ying
A nanostructured organic–inorganic framework, hexagonal NH 2 -MIL-88B, has been prepared through a facile one-pot reflux reaction and then it was characterized using various techniques. The as-prepared sample with high specific surface area (414 m 2 g −1 ) showed excellent adsorption for 2,4,6-trinitrophenol (TNP) in the liquid phase. Detailed studies of the adsorption kinetics, adsorption mechanism, adsorption isotherm, activation energy and various thermodynamic parameters were conducted. The adsorption mechanism of NH 2 -MIL-88B for TNP may be ascribed to hydrogen bond interaction, and the complexation between ─OH in TNP and unsaturated Fe(III) on the surface of NH 2 -MIL-88B. The maximum adsorption capacity of NH 2 -MIL-88B for TNP based on the Langmuir isotherm was 163.66 mg g −1 . The as-prepared NH 2 -MIL-88B adsorbent seems to be a promising material in practice for TNP removal from aqueous solution.
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高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 46
·24598-24607
·
IF 11.301
Chizhong Wang,Rong Wang,Yue Peng,Jianjun Chen,Zhen Chen,Haibo Yin,Junhua Li
Development of new groups of oxygen evolution reaction (OER) electrocatalysts based on transitional metal materials is highly attractive for renewable energy conversion and storage. Here we report a new FeNb (oxy)hydroxide catalyst, which delivered a high OER activity with an overpotential as low as 0.34 V (at 10 mA cm−2). To attain a homogeneous mixing of metal components, niobium was initially incorporated into the framework of iron oxalate dihydrate. The mixed oxalate could be structurally transformed into short-range ordered (oxy)hydroxide, the reactive species for the OER. Incorporation of Nb has been demonstrated to improve the intrinsic OER activity based on Fe species and to accelerate the charge-transfer kinetics across the solid-electrolyte interface. It is also found that strong Fe–Nb interaction can induce the formation of high-valent Fe species. Theoretical calculation results further illustrate the role of NbOx in the OER mechanism, in which Fe serves as the active site and the Nb species can promote the conversion of *OH to *O intermediates to reduce the OER overpotential.
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高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Xiang Li,Xiaoge Chen,Bo Wang,Gang Yu
The development of engineered nanomaterials has aroused great attention in controlling the existence of toxic micropollutants. However, their performance in complex environmental matrices is frequently neglected. Highly efficient enrichment coupled with synergistic degradation with low concentrations is challenging but significant in practical industrial applications. In this study, a large group of active pharmaceutical compounds (PACs) at environmentally relevant concentrations ∼ μg/L were rapidly extracted in core-shell MIL-100 (Fe), followed by effective degradation during the visible-light photo-Fenton process in situ. Unexpectedly, in natural secondary wastewater, adsorption capacities were inhibited (2–50 % decreased after 60 min), while the degradation kinetics of eight PACs were remarkably promoted (1.42–2.92 times higher). Under neutral pH, the accumulated pharmaceuticals within cages were effectively decomposed by •OH and 1 O 2 , mainly derived from visible-light-induced reduction of Fe (III)-cluster and the generation of ROS. The structural parameters (log K ow ) were closely correlated to the adsorption behavior (R 2 = 0.74), which remarkably facilitated the degradation. The powder was loaded onto the PTFE/ultrafiltration membrane in a flow-through reactor. The targeted PACs were rapidly degraded over the self-cleaning surface under visible light irradiation, implying a promising future for industrial application.
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高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Yefei Wang,Fei Chang
The development of supported metal hydride catalysts with abundant active sites is a highly desirable yet challenging endeavor in ammonia synthesis. In this work, a lithium hydride (LiH)-loaded Fe/N-co-doped porous carbon (Fe-N-C) composite (LiH/Fe-N-C) was synthesized and demonstrated as an efficient catalyst for ammonia synthesis under mild conditions. The deposition of LiH onto Fe-N-C induced a partial reduction of the Fe-N moiety, resulting in the slight aggregation of isolated Fe single-atom sites into nanoparticles. Under reducing conditions (in the presence of H2), the coordinated nitrogen in Fe-N-C can be removed, forming nitrogen vacancies (VN), while surface iron hydride species (Fe-H) are generated through the interaction between LiH and Fe-N-C. The presence of Fe atoms adjacent to VN facilitates the adsorption and activation of dinitrogen, a process that is further supported by the replenishment of VN under reaction conditions. Notably, no lithium imide or amide species (Li2NH or LiNH2) — typically regarded as key intermediates in LiH-mediated ammonia synthesis, were observed on LiH/Fe-N-C, likely due to the fast hydrogenation step. Consequently, LiH/Fe-N-C achieves an ammonia production rate of 872 mmol·gFe-1·h-1, surpassing the performance of state-of-the-art Fe-based catalysts at 300 oC and 1 MPa. This study demonstrates that the synergistic catalysis of LiH, transition metals, and their adjacent nitrogen vacancies offers a promising pathway for efficient ammonia synthesis under mild conditions.
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高影响因子
Sustainable Energy & Fuels
·
2025
·
IF 4.1
Yongheng Xiong,Yang Yu,Huangang Shi,Jifa Qu,Wenyi Tan
Single atom Fe sites, doped in CN materials, exhibit outstanding electrochemical activity for CO2-to-CO conversion. The pyrolysis of ZIF8 is a controllable method for fabricating isolated single atom metal sites. In this study, we propose a new strategy to increase the ratio of Fe in ZIF8 precursors by synergistically replacing Zn2+ with Bi3+ and Fe3+. After precursor pyrolysis, the obtained Bi/Fe–N–C catalysts, consisting of Bi sites and pyrrole-type Fe–Nx sites, serve as efficient electrocatalysts for the CO2RR. The results show that the optimized catalyst loaded with 94.8 mg per kgCat Fe exhibits a high FECO of >90.1% over a wide potential range of −0.4 to −0.7 VRHE (98.2% at −0.5 VRHE). Insights into the electrochemical reaction mechanism show that this successful design of Bi/Fe–N–C catalysts can provide a stable catalytic site to form *COOH, thus achieving energy-efficient electrochemical CO2 reduction to CO.
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高影响因子
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