JOURNAL OF ENVIRONMENTAL ENGINEERING
·
2022
·Vol. 148
·期 8
·04022036
·
IF 2.479
Jia Deng,Xiaobao Zeng,Feng Wu,Zheng Fang,Yitao Dai,Li-Zhi Huang
Metal porphyrin structure is believed to be the active site for microbiological reductive dechlorination. In this work, a biomimetic Hemin catalyst was used for the electrochemical dechlorination of trichloroethylene (TCE). Cyclic voltammetric analysis demonstrates the high electrochemical reactivity of Hemin toward reductive dechlorination of TCE, which is further confirmed by controlled potential electrolysis. TCE can be fully dechlorinated to acetylene, ethylene, and ethane. Density functional theory calculations show the appearance of unpaired electron spins on coordinatively unsaturated Fe sites. The breakage of the Fe–Cl bond in Hemin with the formation of coordinatively unsaturated FeII sites shows reactivity toward TCE-to-dichloroethylene (DCE) conversion, but FeII sites with the coordination to Cl atoms have no reactivity. Lowering the applied potential to −2.1 V generates coordinatively unsaturated FeI sites, showing much higher reactivity toward TCE reduction compared with FeII sites. The energy barrier involving complete dechlorination of TCE was decreased from 1.83 eV by FeII sites to 0.86 eV by FeI sites. FeI sites can continue to contribute to TCE dechlorination in electrochemical systems. Our study provides a novel biomimetic electrochemical approach for the dechlorination of TCE in groundwater.
研究领域:
环境化学
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电化学
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催化
·
材料科学
·
理论化学
✓ 已验证
DOI
高影响因子
AICHE JOURNAL
·
2025
·
IF 4
Ying Tang,Dongsheng Xie,Xiaomin Guo,Lining Fang,Hui Zeng,Zebao Rui
Plasmonic photochemical N 2 fixation has received widespread attention owing to the attractive plasmonic enhancement effects in improving solar-to-NH 3 conversion efficiency. However, the weak N 2 adsorption affinity in metallic plasmonic photocatalysts and insurmountable interfacial barriers in metal–semiconductor plasmonic photocatalysts lead to rapid charge carrier recombination instead of participating in N 2 -to-NH 3 conversion. Herein, a photothermal catalyst Fe-dispersed MoO 3− x /MXene with synergistic plasmon resonance hybridization structure is fabricated for photothermal N 2 fixation. The hybrid plasmon resonance effects derived from MXene and MoO 3− x induce a strong optical response across the ultraviolet–visible-near-infrared range and generation of energetic charge carriers, and the induced photothermal effect further accelerates electron extraction, transport, and surface reaction kinetics. Moreover, the abundant oxygen vacancies and Fe sites can intensify the N 2 adsorption and donate the energetic electrons into the anti-bonding system for the stimulative N H coupling process. A high NH 3 formation rate of 87.1 μmol g −1 h −1 is achieved under solar-level illumination.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2025
·
IF 8.4
Yaxing Bai,Xuefeng Hu,Huixian Du,Meng Gao,Zilong Li,Yuhuan Fei
To expand the utilization of discarded walnut shells and enhance the photocatalytic activity of graphitic carbon nitride(g-C 3 N 4 ), the carbon-rich graphitic carbon nitride anchored with Fe sites (FeW-CN) was synthesized via a walnut shell-based biochar-assisted strategy. Unlike the direct thermal copolymerization of melamine for g-C 3 N 4 , the iron-loaded walnut shell-based biochar (FeW) was first synthesized, followed by thermal copolymerization of melamine with FeW to form FeW-CN. The C substitution on the triazine ring enhanced the light absorption and electron migration for FeW-CN. And the Fe sites interacting with N-(C) 3 further improved the migration and the utilization rate of photogenerated carriers. During the degradation of 2-Mercaptobenzothiazole, FeW-CN showed excellent photocatalytic performance and stability compared with g-C 3 N 4 . Moreover, FeW-CN maintained excellent photocatalytic performance in river water. Combination of electron paramagnetic resonance with active species quenching experiments, the synergistic mechanism of singlet oxygen, holes, and superoxide radicals was confirmed in the FeW-CN system. Compared to g-C 3 N 4 , the Fe sites and C substitution enhanced the production of singlet oxygen.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhouyang Ma,Jiawei Wu,Fuling Yang,Shuli Wang,Huan Wen,Ligang Feng
Given its initially low activity and difficulty in active phase formation, Fe site regulation is rarely touched in FeNi-based oxygen evolution reaction (OER) catalysts. Herein, the Fe sites regulation and activity deciphering are demonstrated by selective phase transformation taking nitrogen-doped carbon confined FeNi nanoparticles derived from Fe 2 Ni-MIL-MOF pyrolysis as an example; driven by the reduction atmosphere and Kirkendall effect assisted by melamine pyrolysis, some Fe and Ni sites were separated to form metallic Fe and FeNi alloy and the subsequent fluorination process induced the ionic compound FeF 2 formation rather than NiF 2 , offering a good platform to evaluate the influence of active Fe phase for OER catalysis. Theoretical calculations combined with ex-situ and in-situ spectral characterization techniques proved the complete convention of FeF 2 into a high-valent and reactive intermediate state of FeOOH. Considering the stable metallic state of Ni, the largely improved catalytic performance could be attributed to the Fe site regulation and the subsequent synergistic catalysis effect. Compared to the traditional iron-based catalyst, theoretically, the electronic structure of FeF 2 was more conducive to the active FeOOH phase formation and significantly lowered the reaction energy barrier for OER. By addressing the aforementioned problems, low overpotential and good stability for OER catalysts were realized. The current work showed valid proof of the FeNi-based catalysts regulation via Fe sites for energy-relevant catalysis reactions.
研究领域:
材料科学
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电化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Qiang Zhang,Ranxiao Ao,Ruijie Gao,Huaming Yang
Transition metals with 3d unoccupied orbitals have superior catalytic activity, but inherent high spin suppresses their adsorption capability, leading to sluggish polysulfide conversion kinetics for Li–S batteries. Herein, we provide Fe–O–Si bridge bonds to manipulate eg filling and induce a high-to-medium spin transition of Fe3+ sites, which enhances polysulfide adsorption and facilitates sulfur redox reaction kinetics. The resultant cathodes exhibit outstanding performances under high sulfur loading, which can deliver a high battery specific energy of 1061 mA h·g–1 even after 100 cycles in Li–S pouch batteries. This work provides new insights into the kinetic and multi-step conversion mechanism of the sulfur redox reaction process, helping in the understanding and design of spin-dependent catalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2024
·
IF 6.1
Guiyuan Yang,Fangyuan Hu,Li-Li Cui,Meihong Fan,Xin Ge,Xingquan He,Wei Zhang,Tewodros Asefa
Sustainable electrochemical energy conversion and storage systems are expected to alleviate the energy shortages and environmental crisis that are currently facing the world. To bring the large-scale deployment of these energy systems to reality, the development of highly efficient, sustainable, and stable electrocatalysts is key. In this work, an electrocatalyst composed of homonuclear paired Fe sites coordinated onto N-doped carbon, labelled as Fe2–N–C-900, is reported. The material is synthesized by preparing, and then pyrolyzing at 900 °C, Fe(III)-tetrapyridinylporphyrin-modified zeolitic imidazolate framework-8 (ZIF-8). The electrocatalyst displays excellent activity for the oxygen reduction reaction (ORR), with an onset potential of 0.990 V vs. RHE, a positive half-wave potential of 0.869 V vs. RHE, and a limiting current density of 6.7 mA cm−2, which are all superior to those of the benchmark noble metal-based ORR catalyst Pt/C. This is attributed to its high-density of catalytically active Fe2–N6 sites, large electrochemically active surface area, and small charge transfer resistance. The electrocatalyst also functions well for the ORR on an air electrode in an aqueous zinc–air battery while showing high catalytic activity, remaining stable, and giving a peak power density of 166.3 mW cm−2. Its performance here, too, exceeds that of a Pt/C-based zinc–air battery.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2024
·Vol. 11
·期 5
·2275-2288
·
IF 5.8
Yadan Song,Yalong Liu,Yangju Li,Haipeng Hu,Kexin Huang,Zhe Zhang,Zhongxian Li,Wanning Cao,Kai Jiang,Dapeng Wu
The poor anti-interference ability of radical-dominated processes continues to be a hindrance to the effectiveness of purification and the practical use of peroxymonosulfate-based advanced oxidation processes (PMS-AOPs). Herein, iron, nitrogen, and sulfur co-doped porous carbon sheets (Fe–SNC) were successfully synthesized via a one-step pyrolysis process by adopting Mohr's salt and ZIF-8 sheets as precursors to efficiently activate PMS. Quenching experiments and electron paramagnetic resonance (EPR) characterization indicated that singlet oxygen (1O2) played the most important role in phenol degradation. Based on the variation in the material structure and density functional theory (DFT) calculations, the study revealed the specific mechanism of sulfur embedded in rich Fe3C, Fe4N, and Fe–Nx catalytic sites as an activator of PMS in the degradation of the pollutant of interest. In addition, S-doping sites were shown to shorten the distance between PMS and the catalyst due to electron polarization of the catalyst surface, which facilitated PMS adsorption. According to ultra-high-resolution electrospray time-of-flight mass spectrometry and the predictions of ECOSAR software, the aquatic ecological environment would not be harmed by degradation intermediates. As a consequence, this heterogeneous system possesses admirable anti-interference in pollutant elimination. These conclusions provide instructions for the creation of S-doped porous carbon sheets for effective water treatment.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2020
·Vol. 16
·期 52
·2006113
·
IF 11.459
Zhengyuan Zhang,Jinhui Hao,Yahui Lu,Yuqi Xu,Longhua Li,Weidong Shi
The oxygen evolution reaction is critical to the efficiency of many energy technologies that store renewable electricity in chemical form. However, the rational design of high-performance and stable catalysts to drive this reaction remains a formidable challenge. Here, a facile ink-assisted strategy to construct a series of stable and advanced composite electrocatalysts with single Fe sites for permitting seriously improved performance characteristics is reported. As revealed by a suit of characterization techniques and theoretical methods, the improved electrocatalytic performance and stability can be attributed to the unique coordination states of Fe in the form of distorted Fe O 4 C and the interfacial effect in the composite system that optimize and stabilize single Fe sites in changing to better configurations for intermediates adsorption. The findings provide a novel strategy to in-depth understanding of practical guidelines for the electrocatalyst design for energy conversion devices.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Science
·
2022
·Vol. 10
·期 2
·2204079
·
IF 17.521
Xu Chen,Ziqi Tian,Qihao Yang,Linjuan Zhang,Qiu Yang,Liang Chen,Zhiyi Lu
The reuse of powdered activated carbon (PAC) vitally determines the economics and security of the PAC-based adsorption process, while state-of-the-art PAC regeneration technologies are usually unsatisfactory. Here, it is demonstrated that isolated Fe sites anchored on commercial PAC enable fast H 2 O 2 activation to produce Fe-based reactive oxygen species for highly efficient PAC regeneration at room temperature. Taking rhodamine B as a representative pollutant, PAC decorated with isolated Fe sites realize H 2 O 2 based regeneration with negligible adsorption capacity degradation for 10 cycles. Moreover, in terms of the PAC loss rate, this technology is greatly superior to traditional Fenton-based regeneration technology. Further operando experiments and theoretical calculations reveal that the high regeneration performance can be attributed to the isolated HO FeO motifs, which activate H 2 O 2 via a nonradical reaction pathway. These findings provide a very promising strategy toward reducing the cost of H 2 O 2 -based PAC regeneration technology.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Jinxia Yang,Zhaoxia Hu,Youlei Feng,Zehua Zou,Xiaoping Chen,Qingxiang Wang
Oxygen evolution reaction (OER) is one of the most important issues for hydrogen production from water splitting. During the OER process, electrochemical reconstruction is widely observed for the majority of electrocatalysts, which is strongly related to the formation and evolution of real active species. Herein, bimetal metal-organic framework (MOF) with an equal ratio of Co and Fe sites is screened to exhibit the superior OER property. An obvious reconstruction is observed to transform single MOF phase into the heterostructure composed of active CoOOH and FeOOH. Meanwhile, the generation of Co 3+ species is more reliant on the blessing of electricity and electrolyte than that of Fe 3+ species. As a result, the optimal electrocatalyst shows the overpotential of 267 mV at 10 mA/cm 2 and ultra-low Tafel slope of 24.7 mV/dec with a stable OER performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·Vol. 20
·期 32
·2311132
·
IF 13
Huazhang Guo,Jithu Raj,Zeming Wang,Tianyu Zhang,Kang Wang,Lili Lin,Weidong Hou,Jiye Zhang,Minghong Wu,Jingjie Wu,Liang Wang
Metal phthalocyanine molecules with Me-N 4 centers have shown promise in electrocatalytic CO 2 reduction (eCO 2 R) for CO generation. However, iron phthalocyanine (FePc) is an exception, exhibiting negligible eCO 2 R activity due to a higher CO 2 to * COOH conversion barrier and stronger * CO binding energy. Here, amine functional groups onto atomic-Fe-rich carbon dots (Af-Fe-CDs) are introduced via a one-step solvothermal molecule fusion approach. Af-Fe-CDs feature well-defined Fe-N 4 active sites and an impressive Fe loading (up to 8.5 wt%). The synergistic effect between Fe-N 4 active centers and electron-donating amine functional groups in Af-Fe-CDs yielded outstanding CO 2 -to-CO conversion performance. At industrial-relevant current densities exceeding 400 mA cm −2 in a flow cell, Af-Fe-CDs achieved >92% selectivity, surpassing state-of-the-art CO 2 -to-CO electrocatalysts. The in situ electrochemical FTIR characterization combined with theoretical calculations elucidated that Fe-N 4 integration with amine functional groups in Af-Fe-CDs significantly reduced energy barriers for * COOH intermediate formation and * CO desorption, enhancing eCO 2 R efficiency. The proposed synergistic effect offers a promising avenue for high-efficiency catalysts with elevated atomic-metal loadings.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Research
·
2019
·
IF 0
Ting He,Bingzhang Lu,Yang Chen,Yong Wang,Yaqiang Zhang,John L. Davenport,Alan P. Chen,Chih-Wen Pao,Min Liu,Zhifang Sun,Alexander Stram,Alexander Mordaunt,Jairo Velasco,Yuan Ping,Yi Zhang,Shaowei Chen
Rational design of single-metal atom sites in carbon substrates by a flexible strategy is highly desired for the preparation of high-performance catalysts for metal-air batteries. In this study, biomass hydrogel reactors are utilized as structural templates to prepare carbon aerogels embedded with single iron atoms by controlled pyrolysis. The tortuous and interlaced hydrogel chains lead to the formation of abundant nanowrinkles in the porous carbon aerogels, and single iron atoms are dispersed and stabilized within the defective carbon skeletons. X-ray absorption spectroscopy measurements indicate that the iron centers are mostly involved in the coordination structure of FeN4, with a minor fraction (ca. 1/5) in the form of FeN3C. First-principles calculations show that the FeNx sites in the Stone-Wales configurations induced by the nanowrinkles of the hierarchically porous carbon aerogels show a much lower free energy than the normal counterparts. The resulting iron and nitrogen-codoped carbon aerogels exhibit excellent and reversible oxygen electrocatalytic activity, and can be used as bifunctional cathode catalysts in rechargeable Zn-air batteries, with a performance even better than that based on commercial Pt/C and RuO2 catalysts. Results from this study highlight the significance of structural distortions of the metal sites in carbon matrices in the design and engineering of highly active single-atom catalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
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