WATER RESEARCH
·
2022
·
IF 13.4
Jingli Ren,Yutong Liu,Weimin Cao,Liyang Zhang,Fen Xu,Juan Liu,Yubo Wen,Jian Xiao,Lei Wang,Xiaoxiong Zhuo,Junfeng Ji,Yuanyuan Liu
Sediment-associated Fe(II) is a critical reductant for immobilizing groundwater contaminants, such as Cr(VI). The reduction reactivity of sediment-associated Fe(II) is dependent on its binding environment and influenced by the biogeochemical transformation of other elements (i.e., C, N and Mn), challenging the description and prediction of the reactivity of Fe(II) in natural sediments. Here, anaerobic batch experiments were conducted to study the variation in sediment-associated Fe(II) reactivity toward Cr(VI) in natural sediments collected from an intensive agricultural area located in Guangxi, China, where nitrate is a common surface water and groundwater contaminant. Then, a process-based model was developed to describe the coupled biogeochemical processes of C, N, Mn, Fe, and Cr. In the process-based model, Cr(VI) reduction by sediment-associated Fe(II) was described using a previously developed multirate model, which categorized the reactive Fe(II) into three fractions based on their extractabilities in sodium acetate and HCl solutions. The experimental results showed that Fe(II) generation was inhibited by NO 3 - and/or NO 2 − . After NO 3 − and NO 2 − were exhausted, the Fe(II) content and its reduction rate toward Cr(VI) increased rapidly. As the Fe(II) content increased, the three reactive Fe(II) fractions exhibited approximately linear correlations with aqueous Fe(II) concentrations ( C F e 2 + ), which was probably driven by sorptive equilibrium and redox equilibrium between aqueous and solid phases. The model results indicated that the reaction rate constants of the three Fe(II) fractions ( k n ) significantly increased with incubation time, and log( k n ) correlated well with C F e 2 + [ log ( k 1 ) = 2.84 C F e 2 + − 0.17 , log ( k 2 ) = 5.90 C F e 2 + − 2.49 and log ( k 3 ) = 3.09 C F e 2 + − 3.37 ]. The numerical model developed in this study provides an applicable method to describe and predict Cr(VI) removal from groundwater under dynamic redox conditions .
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DOI
高影响因子
CRYSTENGCOMM
·
2021
·Vol. 23
·期 43
·7650-7657
·
IF 3.545
Tingting Sun,Shuangyan Lin,Zhikun Xu,Lin Li
Two-dimensional (2D) metal–organic frameworks (MOFs) with highly exposed electro-active surface are regarded as promising oxygen evolution reaction (OER) electrocatalysts. This work demonstrates the in situ conversion of NiCo-LDH (LDH: double-layer hydroxide) into an Fe-doped NiCo-MOF on a conductive substrate (Fe-NiCo-MOF/NF) by a two-step hydrothermal method. The hierarchical book-like structure of the Fe-NiCo-MOF/NF electrode provides a large electro-active surface and improved electron transport capability, leading to enhanced oxygen evolution performance in an alkaline environment. Specifically, Fe-NiCo-MOF/NF needs an overpotential of 290 mV to drive a current density of 50 mA cm−2, which is 136 mV lower than that of the precursor NiCo-LDH. Additionally, its activity can be maintained for at least 20 h at a high current density of 200 mA cm−2. Moreover, the real active centers of the catalyst were discovered to be the metal oxides converted during the OER cycles. This work used a simple hydrothermal method to enhance the OER performance, which is convenient for direct application of MOF materials in electrocatalysis fields.
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高影响因子
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.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Cailing Song,Qianwen Jin,Wen Zhang,Chenchen Hu,Zhumabay Bakenov,Yan Zhao
Lithium-sulfur (Li-S) batteries have drawn a lot of attention owing to the high theoretical capacity of 1675 mAh g −1 , environmental friendliness and relative abundance of sulfur. Nevertheless, the severe dissolution and migration of lithium polysulfides (LiPSs) and poor conductivity of sulfur greatly hinder the practical application of Li-S batteries. In this work, Fe-Ni-P@nitrogen-doped carbon (named as Fe-Ni-P@NC) derived from Fe-Ni Prussian blue analog (Fe-Ni PBA) was used as highly efficient sulfur host for Li-S batteries. The Fe-Ni-P particles not only enhance the adsorption of LiPSs but also effectively promote the conversion of LiPSs. In addition, the CN – of PBAs can readily generate nitrogen-doped carbon during pyrolysis, which can improve the conductivity of composites. Due to these advantages, Li-S batteries using S@Fe-Ni-P@NC composites cathodes exhibited good electrochemical performance with outstanding rate capability and stable cycling over 500 cycles with a lower capacity fading rate of 0.08% per cycle at 1 C.
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高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Liping Fang,Baolin Gao,Fangbai Li,Kai Liu,Jialin Chi
The incorporation of secondary metal atoms into iron oxyhydroxides may regulate the surface chemistry of mediating electron transfer (ET) and, therefore, the biogeochemical pollutant processes such as arsenic (As) in the subsurface and soils. The influence of incorporating two typical metals (Cu and Zn) into a specific {001} hematite facet on O 2 activation by surface-bound Fe(II) was addressed. The results showed that Cu-incorporated hematite enhances As(III) oxidation in the presence of Fe(II) under oxic conditions and increases with increasing Cu content. Conversely, Zn incorporation leads to the opposite trend. The As(III) oxidation induced by surface-bound Fe(II) is positively related to the Fe(II) content and is favorable under acidic conditions. Reactive oxygen species (ROS), such as superoxide (·O 2− ) and H 2 O 2 , predominantly contribute to As(III) oxidation as a result of 1-electron transfer from bound Fe(II) to surface O 2 on hematite and radical propagation. Electrochemical analysis demonstrates that Cu incorporation significantly lower the oxidation potential of Fe(II) on hematite, whereas Zn led to a higher reaction potential for Fe(II) oxidation. Subsequently, distinct surface reactivities of hematite for the activation of O 2 to form ROS by surface-bound Fe(II) are evidenced by metal incorporation. Our study provides a new understanding of the changes in the surface chemistry of iron oxyhydroxides because of incorporating metals (Zn and Cu), and therefore impact the biogeochemical processes of pollutants in soils and subsurface environments.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Yali Guo,Xu Xing,Yanan Shang,Baoyu Gao,Lei Zhang,Qinyan Yue,Li Qian,Zihang Wang
To insight into the selective adsorption mechanism of fluoride in the bimetallic system, Fe-La or Al-La composites were comparatively embedded onto the cellulose/graphene hybrids (CG hybrids) to fabricate the Fe-La@CG hybrids or Al-La@CG hybrids for fluoride uptake with existing phosphate. The results showed that Al-La@CG hybrids were mainly in the amorphous nature, while Fe-La@CG hybrids have the identical diffraction peaks as compared with those of hydrated lanthanum oxides (HLO) and hydrated iron oxides (HFO). Fluoride capture by Al-La@CG and Fe-La@CG hybrids followed the similar tendencies with the pH altering, but the adsorption performance of Al-La@CG hybrids was better than that of Fe-La@CG hybrids at the same pH levels. Adsorption of fluoride onto Al-La@CG hybrids exhibited less sensitivity and high selectivity with existing phosphate as compared with that of Fe-La@CG hybrids, which further indicated that the Al-La@CG hybrids were more preferable for fluoride adsorption. The fraction areas of La-F and Al-F accounted for 79.1 % and 20.9%, which indicated that the fluoride onto the Al-La@CG hybrids was mainly based on the La species. Similarly, La-F in exhausted Fe-La@CG hybrids accounted for 55.6%, higher than that (44.4%) of Fe-F.
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Lin Li,Shuiyun Shen,Guanghua Wei,Xiaolin Li,Kun Yang,Qi Feng,Junliang Zhang
There remain great challenges in exploring cost-effective and highly efficient non-noble metal electrocatalysts to catalyze the oxygen reduction reaction (ORR) of proton exchange membrane fuel cells (PEMFCs). Also, a further validation on their performances under a fuel cell operating condition draws sustained attention. Herein, we report a comprehensive investigation on the ORR performances of a series of pyrolyzed Fe–N–C composites that use phenanthrolene as the nitrogen precursor, and the effects of carbon supports, transition metal precursors, and annealing temperatures are examined in detail. Electrochemical measurements combined with different physicochemical characterizations are employed to clarify the function of critical structures including the specific surface area, microstructure, nitrogen content, nitrogen type, and corresponding proportion on their ORR and fuel cell performances. It demonstrates a half-wave potential of 0.79 V and almost a four-electron pathway. When using the as-optimized Fe–N–C composite as the cathode catalyst of a PEMFC, the maximum power density reaches as high as 540 mW cm–2.
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高影响因子
Inorganic Chemistry Frontiers
·
2024
·
IF 6.1
Qingtao Wang,Xia Hu,Kai Cui,Yanxia Wu,Guofu Ma,Ziqiang Lei,Shufang Ren
An oxygen reduction reaction (ORR) catalyst is a crucial component of metal–air batteries. Herein, modified carbon nanotubes are used to support iron phthalocyanine, followed by the fabrication of single-atom and cluster coexisting catalysts by the fast microwave method. The two catalysts have Fe–N5 and Fe–P–N4 coordination structures, respectively. Electrochemical tests show that the FeNC/Fe–N5–C and FeNC/Fe–P–N4–C catalysts have half-wave potentials of 0.906 and 0.886 V in an alkaline solvent, respectively. The Zn–air battery prepared with the FeNC/Fe–N5–C catalyst has a specific capacity of 791 mA h g−1 and a maximum power density of 190 mW cm−2. DFT calculations show that the axial coordination bonds in FeNC/Fe–N5–C and FeNC/Fe–P–N4–C are conducive to the acceleration of the transfer of electrons. The d-band centers of the axial coordination Fe–N5 and Fe–P–N4 are closer to the Fermi level, confirming that the presence of the axial coordination bonds enhances the adsorption of the reaction intermediates and reduces the ORR barriers.
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高影响因子
TETRAHEDRON
·
2011
·Vol. 67
·期 41
·7909-7912
·
IF 3.011
Wei Lu,Han Jiang,Fangyu Hu,Liming Jiang,Zhiquan Shen
A novel fluorogenic receptor 1 was prepared by the reaction of thiosemicarbazide with 1-naphthaldehyde. Based on in situ-formed 1 –Fe(III) complexes having the specific binding affinity for F − anions, this sensory system allows rapid recognition and quantitative detection of fluoride in neutral aqueous media in an ‘off–on’ fashion. The fluoride measurement method not only exhibits a low detection limit but also has strong anti-interference ability to common coexisting ions, as evidenced by competitive experiments.
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高影响因子
Journal of Physical Chemistry C
·
2017
·
IF 4.536
Wanfeng Li,Fang Zhang,Xingde Xiang,Xiucheng Zhang
Nickel-based ferrocyanides have attracted wide interest as cathode for aqueous sodium-ion batteries in fields of sustainable energies such as wind and solar, owing to excellent cycling stability and high-rate capability. However, they suffer from low specific capacities (∼60 mAh g–1). Herein, Na2Ni0.4Co0.6[Fe(CN)6] nanocrystallites are reported for the first time as high-capacity cathode for aqueous sodium-ion batteries. Its electrochemical properties and redox mechanism have been understood by combining the X-ray diffraction technique, Fourier-transform infrared spectroscopy, cyclic voltammetry, electrochemical impedance microscopy, and charge/discharge measurements. It is revealed that the material undergoes a reversible three-step single-phase reaction mechanism during Na extraction through sequential electrochemical oxidation of nitrogen-coordinated Co2+ ions and carbon-coordinated Fe2+ ions and achieves superior electrochemical performance with a high reversible capacity of 85 mAh g–1 at 0.5 C, an average operating potential of 0.62 V (vs Ag/AgCl), and a high capacity retention of 90% after 100 cycles. The combination of high specific energy and good cycling performance enables the Na2Ni0.4Co0.6[Fe(CN)6] material exhibiting promising application for high-performance aqueous sodium-ion batteries.
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高影响因子
ANALYST
·
2013
·Vol. 138
·期 16
·4526-4531
·
IF 3.969
Ya Li Liu,Xi Juan Zhao,Xiao Xi Yang,Yuan Fang Li
In this paper, a nanosized porous metal–organic framework, Fe-MIL-88NH2, was facilely prepared with a uniform octahedral shape by the addition of acetic acid, and for the first time was demonstrated to possess intrinsic peroxidase-like activity. Kinetic analysis and electron spin resonance measurements indicated that the catalytic behavior was consistent with typical Michaelis–Menten kinetics and follows a ping-pong mechanism. As a novel peroxidase mimic material, Fe-MIL-88NH2 shows the advantages of high catalytic efficiency, ultrahigh stability and high biocompatibility in aqueous medium compared with natural enzymes and other peroxidase nanomimetics. Here, Fe-MIL-88NH2 was used to quickly catalyze oxidation of the peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 to produce a colored product, which provided a simple, sensitive and selective method for the colorimetric detection of glucose. Glucose could be linearly detected in the range from 2.0 × 10−6 to 3.0 × 10−4 M with a detection limit of 4.8 × 10−7 M, and the color variation for glucose response was also obvious by visual observation at concentrations as low as 2.0 × 10−6 M. More importantly, the colorimetric method could be successfully applied to the determination of glucose in diluted serum samples.
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CHINESE JOURNAL OF CATALYSIS
·
2025
·
IF 17.7
Xu Lin,Danyang Li,Shiqing Huang,Panpan Sun,Yan Huang,Shitao Wang,Lirong Zheng,Dapeng Cao
The limited activity of atomically-dispersed M-N-C electrocatalysts severely restricts their applicability in the oxygen reduction reaction (ORR) for proton exchange membrane fuel cells (PEMFC). Herein, we design and synthesize Se-doped Fe-N-C hierarchical porous electrocatalyst (FeN 4 /SeC 2 ) by optimizing carbon structure and FeN 4 coordination environment. The FeN 4 /SeC 2 electrocatalyst exhibits outstanding ORR activity in 0.1 mol L –1 HClO 4 , and the resulting PEMFC presents a peak power density of 1.20 W cm –2 in H 2 -O 2 condition at a back pressure of 200 kPa, ranking in the top levels among most reported non-precious metal catalyst-based fuel cells. The lower O 2 transfer resistance of FeN 4 /SeC 2 -based membrane electrode assembly than FeN 4 -based one means faster O 2 transport in triple-phase boundary (TPB), and Density functional theory calculation further reveals that the synergistic catalysis between porous SeC 2 and FeN 4 -OH species can efficiently lower the energy barriers for the rate-determining step of the ORR. In short, the outstanding performance of FeN 4 /SeC 2 in PEMFC is ascribed to the Se-doping, which introduces more defects and larger mesoporosity and therefore facilitates ionomer infiltration and O 2 transfer and charge transfer in TPB. The effective strategy of enhancing mass and charge transfers in TPB is anticipated to be applicable in the construction of highly efficient ORR electrocatalysts.
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