PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2021
·Vol. 23
·期 8
·4690-4699
·
IF 3.676
Zhengyan Zhao,Wei Liu,Yantao Shi,Heming Zhang,Xuedan Song,Wenzhe Shang,Ce Hao
We report a combination of experimental and computational mechanistic studies for the photoreduction of CO2 to CO with water, catalyzed by single-atom Fe supported on graphitic carbon nitride (g-C3N4). Density functional theory (DFT) and time-dependent DFT (TDDFT) methods were utilized to explore the behavior of single-atom Fe in g-C3N4, which is of vital importance to the understanding of the CO2 reduction reaction (CO2RR) mechanism. The calculation results reveal that the rate-limiting step of the hydrogen-bonded complex in the absence of Fe atoms is the cleavage of C–O bonds in COOH radicals during the whole CO2RR, which includes the photophysical and photochemical processes. The presence of Fe atoms not only activated CO2 in the ground state and increased the rate constant of the limiting step in the photophysical process, but also functioned as the catalytic active center, lowering the reaction barrier of the C–O bond cleavage in COOH˙ in the photochemical process and resulting in improved photocatalytic activity. In addition, DFT calculations further demonstrated that the electron and proton transfer involved in the photophysical and photochemical processes is closely related to and induced by the hydrogen bonds in the excited state.
研究领域:
材料科学
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催化化学
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环境科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Fawen Liang,Zhang Liu,Xueding Jiang,Jiesen Li,Kaibang Xiao,Weicheng Xu,Xin Chen,Jinzhi Liang,Zhifeng Lin,Meng Li,Xiaolian Wu,Hailong Wang
In this study, NaOH-modified biochar supported Fe/Mn bimetallic composite (Fe-Mn/AW-BC) was prepared to remove tetracycline (TC) through activating peroxymonosulfate (PMS). Results showed that about 97.9 % of TC was degraded and the rate constant of Fe-Mn/AW-BC + PMS system was 37 folds higher than BC + PMS system. Experimental results confirmed that both radical and non-radical pathway were contribute to the catalytic system. Density functional theory (DFT) results also suggested that Fe-Mn/AW-BC sample was favorable for adsorbing PMS based on the length O O bond from PMS and the E ads of catalysts. The superior activation ability was ascribed to the accelerating formation of reaction active species and other oxidation species by bimetallic structures of Fe-Mn and oxygenated functional groups of BC. Additionally, the redox cycles of Fe 3+ /Fe 2+ and Mn 3+ /Mn 2+ under Fe-Mn-BC synergism promoted the generation of the radicals, whereas the carbon shell effectively inhibited metals leaching of Fe-Mn/AW-BC, and 77.8 % of TC can be still removed within 60 min after five consecutive cycles. Notably, Fe-Mn/AW-BC system has special characteristic of wide pH usable range and broad-spectrum adaptability towards various organic pollutants and various water environments. Based on intermediate identification and Fukui function calculation, the degradation pathways of TC were also proposed. This study highlights the applications of biochar for the environmental catalysis.
研究领域:
环境科学
·
催化材料
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Kuangfu Huang,Ruohao Dong,Chao Wang,Wen Li,Hongxia Sun,Baoyou Geng
Design and synthesis of highly efficient, stable, and low-cost catalysts have a crucial role in the study of electrolytic water. In this work, a novel Fe–Ni layered double hydroxide (LDH) material with homogeneous heterostructures is successfully synthesized by a two-step hydrothermal method. Compared with the ordinary Fe–Ni LDH arrays prepared by one step, this structure has a rougher surface, so it has a more extensive active area, thus providing more active sites. Due to the synergistic effect of different elements and more exposure of active sites, the catalytic effect of this material for water splitting is outstanding. The post-optimized FeNi@FeNi electrode exhibits extraordinary OER (oxygen evolution reaction) and HER (hydrogen evolution reaction) performance with OER overpotentials of 193, 231, and 306 mV and HER overpotentials of 127, 173, and 253 mV when the current density is 10, 20, and 50 mA·cm–2, respectively. The improved electrolytic water performance reveals that the design of homogeneous heterostructures is maybe an alternative route to exploit high-efficiency catalysts and promote the application of nonprecious metal catalytic materials.
研究领域:
材料科学
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电化学
·
催化
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DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Xiaohui Wang,Zhilong Cheng,Bingrong Liu,Huiyi Liu,Xin Fang,Ruiqi Chai,Lishuang Ma,Yuchao Lyu,Jianye Fu,Xinmei Liu
Methane dehydroaromatization (MDA) was a promising technology for the synthesis of high value-added aromatics through natural gas. Fe/ZSM-5 catalysts were widely used in MDA reaction. However, its catalytic mechanism remained ambiguous. In this work, a novel one-pot strategy was developed for the preparation of Fe/ZSM-5 catalysts, which can delicately control the iron species and acidic property of Fe/ZSM-5 catalysts. In-situ DRIFTS and DFT calculation demonstrated that MDA followed a bifunctional mechanism and the second C–H bond breaking process of CH 4 was the rate-determining step, where methane underwent coupling and dehydrogenation at the iron active sites to generate intermediate species (ethylene), and Brønsted acid sites played a key role in determining the selectivity of aromatics. Moreover, CO-pulse chemisorption revealed the quantitative synergistic effect between metal active sites and Brønsted acid sites. Catalysts with highly dispersed iron oxide and proper density of Brønsted acid sites exhibited the best catalytic performance. This study elucidated the catalytic roles of iron species and Brønsted acid sites in Fe/ZSM-5 catalysts in MDA and provided guidance for the future development of highly active MDA catalysts.
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产品关联
DOI
高影响因子
Materials Today Physics
·
2021
·
IF 9.298
A. Wang,Y. Hu,H. Wang,Y. Cheng,T. Thomas,R. Ma,J. Wang
To improve the structure-dominant activity, rational design of oxide-based materials remains challengeable in bifunctional oxygen electrocatalysis , especially from the perspective of electronic modulation. Herein, we demonstrate that the electron configuration of inverse spinel NiCo 2 O 4 can be activated by controllable substitution of Fe into the octahedral centers. Fe-substituted NiCo 2 O 4 nanoparticles embedded in porous N-doped carbon nanofibers (NiCo 2- x Fe x O 4 /NCNF), which were synthesized by scalable electrospinning, exhibit a correlated relationship with Fe atomic content and achieve an optimal bifunctional activity (ΔE = 0.74 V) at 0.25 at.%. Theoretical calculation shows that the substitution of Co 3+ by Fe 3+ modulates the electrons filling in e g orbital of octahedral cation via delocalizing the electrons around O anions. The increased density of states around the Fermi level further regulate the adsorption energy of oxygen intermediates and lead to better bifunctional performance than commercial Pt/C + RuO 2 in rechargeable Zn-air battery. This work provides a new pathway to develop cost-effective bifunctional electrocatalysts for electrochemical energy storage and conversion .
研究领域:
材料科学
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电化学
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储能与转换
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DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 46
·30145-30156
·
IF 4.036
Haoming Ning,Zhi Zhang,Chunhai Shi,Xiaolei Ma,Jian Li,Hongyi Zhu,Jiawei Hu
In this study, Fe/N codoped porous graphitic carbon derived from macadamia shells was prepared at different temperatures as cathodic catalysts for microbial fuel cells (MFCs), with K2FeO4 as a bifunctional catalyst for porosity and graphitization. The catalyst prepared at 750 °C (referred to as MSAC-750) showed a large specific surface area (1670.3 m2 g−1), graphite structure, and high pyridine-N and Fe-NX contents. Through the electrochemical workstation test, MSAC-750 shows excellent oxygen reduction reaction (ORR) activity, with an onset potential of 0.172 V and a half-wave potential of −0.028 V (vs. Ag/AgCl) in a neutral medium, and the ORR electron transfer number is 3.89. When applied to the MFCs as cathodic catalysts, a higher maximum power density and voltage of 378.68 mW m−2 and 0.425 V were achieved with the MSAC-750 catalyst and is superior to that of the Pt/C catalyst (300.85 mW m−2 and 0.402 V). In this case, a promising method is hereby established for the preparation of an excellent electrochemical catalyst for microbial fuel cells using inexpensive and easily available macadamia shells.
研究领域:
材料科学
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环境工程
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能源科学
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DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Wei Wu,Wei Zhang,Yu Long,Jiaheng Qin,Jiantai Ma
Carbon material derived from certain MOF usually still has plenty of microporous structures, the mass transfer process is severely limited. In this work, in the assistance of dicyandiamide, nitrogen doped carbon confined atomically dispersed Fe species (Fe–N–C) with interconnected mesoporous pores by a facile one-step pyrolysis process of Fe-doped zeolitic imidazolate framework (Fe-doped ZIF) is prepared. Through simply adjusting the amount of dicyandiamide added, Fe–N–C with various morphologies, pore structures and chemical compositions could be obtained. The specific surface area of the materials increases first and then decreases with the increase content of dicyandiamide, and the pore structure also changes accordingly. Fe–N–C possesses the largest specific surface area with interconnected pore structure when the mass ratio of dicyandiamide to Fe-doped ZIF reaches 1:1 (Fe–N–C–1). And Fe–N–C–1 shows the optimal catalytic activity compared with other catalysts for the transfer hydrogenation of halonitrobenzenes. Moreover, the Fe–N–C–1 exhibits good stability and could be reused without obvious decrease of catalytic activity. This work may afford certain thought for rationally designing high-performance catalysts derived from MOF .
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Qizhan Zhang,Minghua Zhou,Xuedong Du,Pei Su,Wenyang Fu,Ge Song
To simultaneously improve the H 2 O 2 electrosynthesis, Fe(II) regeneration and pH application range in EF process, a highly efficient dual-cathode electro-Fenton (EF) process using easily available Fe(III) as catalysts for the treatment of organic wastewater at a wide pH range was first proposed, in which natural air diffusion electrode (NADE) was designed as one cathode for H 2 O 2 production without aeration and the modified carbon felt (MCF) was acted as the other cathode mainly for Fe(II) regeneration. Nitric acid modification significantly enhanced the electrochemical properties of CF and introduced more oxygen-containing functional groups. The Fe(II) regeneration rate of MCF with higher electroactive surface area was 4.7 times that of CF cathode at pH 7. It was found that as the homogeneous Fe(III) was hydrolyzed into solid hydroxides, the accompanying H + decreased the solution pH and MCF not only accelerated the dissolved Fe(III)/Fe(II) cycle but also reduced the adsorbed solid iron to ≡Fe(II) on the cathode surface. This simultaneously promoted the homogeneous and heterogeneous Fenton reactions and enhanced the efficiency of EF degradation process. For bronopol, 2,4-dichlorophenoxyacetic acid, sulfamethazine and phenol (100 mg L −1 ), the process had TOC removal of 48%−72% within 60 min with the corresponding mineralization current efficiency of 16.5%−56.2%, and the electrical energy consumption <0.225 kWh (gTOC) −1 , which all greatly advantaged over that of the conventional EF. Therefore, this process is efficient and low-cost, being very promising for the treatment of organic wastewater.
研究领域:
环境科学
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污水处理
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电化学技术
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DOI
高影响因子
Nano Research
·
2024
·
IF 9.5
Liu Dong-Xue,Deng Xin,Zhu Yong-Fu,Meng Zhe,Sun Xue-Feng,Shi Miao-Miao,Zhong Hai-Xia,Yan Jun-Min
Electrocatalytic reduction of nitrate \(({\rm{N}}{{\rm{O}}_3}^ - )\) and nitride \(({\rm{N}}{{\rm{O}}_2}^ - )\) to ammonia (NH 3 ) is of wide interest as a promising alternative to the energy-intensive Haber-Bosch route for mitigating the vast energy consumption and the accompanied carbon dioxide emission, as well as benefiting for the relevant sewage treatment. However, exploring an efficient and low-cost catalyst with high atomic utilization that can effectively facilitate the slow multi-electron transfer process remains a grand challenge. Herein, we present an efficient hydrogenation of \({\rm{N}}{{\rm{O}}_3}^ - /{\rm{N}}{{\rm{O}}_2}^ - \) species to NH 3 in both alkaline and neutral environments over the Fe 2 (MoO 4 ) 3 derived hybrid electrocatalyst with the metallic Fe site on FeMoO 4 (Fe/FeMoO 4 ). The Mo ingredient can play a synergistically positive role in further promoting the NH 3 production on Fe. As a result, Fe/FeMoO 4 behaves well in the electrochemical NH 3 generation from \({\rm{N}}{{\rm{O}}_2}^ - \) with a maximum NH 3 Faradaic efficiency (FE) of 96.53% and 87.68% in alkaline and neutral electrolyte, corresponding to the NH 3 yield rate of 640.68 and 302.56 \({\rm{mg}} \cdot {{\rm{h}}^{ - 1}} \cdot {\rm{m}}{{\rm{g}}_{{\rm{cat}}.}}^{ - 1}\) , respectively, which outperforms the Fe and Mo counterpart and other similar catalyst, showing the robust catalytic capacity of each active site.
研究领域:
催化
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电化学
·
环境科学
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材料科学
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DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Kaijie Wei,Xiaoya Feng,Hao Jiang,Chunzhong Li,Yanjie Hu
In recent years, the development of heat-resistant silicone rubber has been a research hotspot. In this paper, a kind of Fe doped TiO 2 nanoparticles (Fe-TiO 2 ) was prepared via flame spray pyrolysis, which can significantly improve the high temperature resistance of silicone rubber. The results show that, on the one hand, the prepared Fe-TiO 2 can inhibit the breakage of Si-O main chain; on the other hand, because Fe is doped into the lattice of TiO 2 , it causes the change of TiO 2 crystal phase and produces more oxygen vacancies, which is more beneficial to capture free radicals in silicone rubber matrix, so that Fe-TiO 2 can effectively inhibit the excessive cross-linking of silicone chain caused by methyl oxidation on the side of silicone rubber. TGA results showed that after adding Fe-TiO 2 , the 5 % thermal weight loss temperature of methyl vinyl silicone rubber increased from 392.8 °C to 435.6 °C.
研究领域:
材料科学
·
高分子化学
·
纳米技术
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Hui Huang,Bin Huang,Yichun Huang,Jinbei Yang,Yinnv Ye,Yucheng Chen
Attractive environmentally friendly magnetic metal-organic framework (MOF) nanocomposite GO@Fe 3 O 4 -COOH@NH 2 -MIL-101(Fe) was synthesized by a solvothermal method and characterized by X-ray diffraction, Fourier transform infrared, scanning electron microscopy, Brunauer– Emmett–Teller, and vibrating sample magnetometer, and used as an effective adsorbent for the removal of orange G from aqueous solution. The various operating parameters that effect the adsorption process, such as adsorbent dosage (0.01–0.2 g), pH (1.0–10.0), initial concentration (50–400 mg L –1 ), and temperature (298.15–318.15 K) were studied. The percent removal of orange G increases with the increment of the adsorbent dosage and decrease of the initial concentration, and the optimum pH is 6.0. The Redlich–Peterson model can be favorably applied to describe the adsorption equilibrium data, indicating that the surfaces of GO@Fe 3 O 4 -COOH@NH 2 -MIL-101(Fe) nanocomposite for the orange G adsorption are made up of homogeneous adsorption patches. The adsorption kinetics indicate that the adsorption process of GO@Fe 3 O 4 -COOH@NH 2 -MIL-101(Fe) toward orange G obeys the pseudo-second-order model and the activation energy is 16.5 kJ mol –1 . Thermodynamic parameters, ΔH = 39.81 kJ mol –1 , ΔS = –46.80 J mol –1 K –1 , and ΔG < 0, exhibit that the adsorption is exothermic and spontaneous. The maximum adsorption capacity of orange G onto GO@Fe 3 O 4 -COOH@NH 2 -MIL-101(Fe) nanocomposite is 128.8 mg g –1 . Therefore, magnetic GO@ Fe 3 O 4 -COOH@NH 2 -MIL-101(Fe) nanocomposite can be employed as an environmentally friendly and efficient adsorbent for the orange G removal from wastewater.
研究领域:
环境科学
·
纳米技术
·
材料科学
·
化学工程
·
水处理
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DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 68
·38850-38859
·
IF 2.936
Yaozu Guo,Dong Zhao,Junhua You,Wenli Pei,Yingdong Qu,Xiaoyang Wang,Qingyu Meng
Nd2Fe14B nanoparticles were successfully prepared by using a low-energy chemical method. The microscopic characteristics and formation mechanisms of the phases were investigated at each stage during the preparation of Nd-Fe-B nanoparticles. The Nd-Fe-B intermediates, Nd-Fe-B oxides and reduced Nd-Fe-B nanoparticles were detected and analyzed by using TEM, STEM, XRD, SEM, VSM and Rietveld calculations. The results showed that the intermediate of Nd-Fe-B consisted of Fe3O4 and Nd and Fe elements surrounded by nitrile organic compounds. The Nd-Fe-B oxide was composed of NdFeO3 (48.619 wt%), NdBO3 (31.480 wt%) and α-Fe (19.901 wt%), which was formed by the reaction among Nd, Fe3O4 and B2O3. NdFeO3 and NdBO3 exhibited a perovskite-like lamellar structure, and the grain size was smaller than that of α-Fe. Nd-Fe-B particles were mainly composed of Nd2Fe14B and α-Fe phases. The small particles of NdFeO3 and NdBO3 and the interstitial position between oxide particles and α-Fe were more favorable for the formation of Nd2Fe14B particles. At the same time, the surface of α-Fe particles can also diffuse to form Nd2Fe14B nanoparticles. The coercivity of Nd-Fe-B particles was 5.79 kOe and the saturation magnetization was 63.135 emu g−1.
研究领域:
材料科学
·
纳米材料
·
磁性材料
·
无机非金属材料
·
固体化学
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DOI
高影响因子