APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
·
IF 19.503
Hongbo Lu,Chunli Wang,Xueming Liu,Jing Zhang,Zhang Lin,Zhengping Hao,Gang Pan
Arsenic sulfide sludge (ASS) is a typical precipitation product of acid smelting wastewater. Previous study reported that when exposed to sunlight, the release and oxidation of As(III) in ASS were markedly accelerated. However, the key factor to trigger the photocatalytic transformation of ASS is still unclear. Herein, we revealed that the coexisting Fe(II)/Fe(III) ions were critical to promote the photo-oxidation of released As(III) under visible light. We further validated that Fe(II)-stimulated photo-oxidation mechanism of As(III) in ASS was pH-dependent. In acid conditions, OH and SO 4 − were promoted by Fe(II)/Fe(III) cycling catalysis with the assistance of the reductive sulfur species from ASS, e.g. S 2− and SO 3 2− , and thus accelerated the oxidation of As(III). While in neutral conditions, the nascent ferric hydroxide colloids enhanced the oxidation rate of As(III) via photo-induced ligand-to-metal-charge transfer (LMCT) mechanism. These findings help in predicting and controlling the fate of real arsenic-containing sludge in sunlit environments.
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JOURNAL OF HAZARDOUS MATERIALS
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2021
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IF 10.588
Yuehui Tan,Xirui Wan,Ting Zhou,Le Wang,Xianqiang Yin,Aisheng Ma,Nong Wang
In this study, a novel adsorbent made from kiwi branch biochar modified with Zn-Fe (KB/Zn-Fe) was compared with original biochar to the Pb(II)'s adsorptivity from waste water. The adsorbent was synthetized by liquid-phase deposition. Batches of sorption tests were performed, and the biochars' representative properties were tested. Characterizations revealed the physicochemical properties of biochars and showed that the KB/Zn-Fe composites were successfully synthesized. The Langmuir model and pseudo-second-order kinetic model were proven to satisfactorily fit the original biochar and KB/Zn-Fe. The KB/Zn-Fe showed Langmuir maximum adsorption ability to Pb (II) in aqueous solution of 161.29 mg g -1 , compared with 36.76 mg g -1 for original biochar. The adsorption ability of Pb(II) decreased and the Pb(II) removal efficiency increased with increasing biochar dose. The effect of co-existence of NO 3 - to the absorptive capacity of KB/Zn-Fe on Pb(II) was unremarkable, but Cl - could increase the absorptive capacity. Multiple Pb(II) adsorption mechanisms by KB/Zn-Fe include surface precipitation of metal hydroxides, complexation with active functional groups and ion-exchange. This work provides guidance for future production of biochar with efficient adsorption ability, which could be used to remove Pb(II) ions from wastewater.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2021
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IF 3.764
Yuzhou Wu,Xubin Zhang,Fumin Wang,Yi Zhai,Xianbao Cui,Guojun Lv,Tao Jiang,Jiaqi Hu
Direct hydroxylation of benzene to phenol is an effective and environment-friendly route to obtain phenol. Herein, Fe-doped and cupric acetylacetonate [Cu(acac)2]-grafted mesoporous silica (Cu/Fe-SBA-15) with highly dispersed metallic sites has been synthesized and used as a heterogeneous catalyst in the hydroxylation of benzene. The physiochemical properties of the synthesized materials as well as the reciprocity between iron and copper sites were analyzed by several characterization techniques including nitrogen adsorption–desorption, X-ray diffraction, transmission electron microscopy, UV–vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. In direct hydroxylation of benzene with H2O2 as the oxidant, the prepared Cu/Fe-SBA-15 material showed great catalytic activity. Moreover, the synergistic effect between doped Fe sites and grafted Cu sites was also investigated. In this catalyst, Fe and Cu species both played the role of active sites. Excessive activity of iron would lead to benzene peroxidation, while the presence of copper sites could effectively hinder benzene peroxidation.
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Nature Communications
·
2021
·Vol. 12
·期 1
·1-10
·
IF 14.919
Liu Gongquan,Zhao Yi-Lei,He Fangyuan,Zhang Peng,Ouyang Xingyu,Tang Hongzhi,Xu Ping
Biodegradation of aromatic and heterocyclic compounds requires an oxidative ring cleavage enzymatic step. Extensive biochemical research has yielded mechanistic insights about catabolism of aromatic substrates; yet much less is known about the reaction mechanisms underlying the cleavage of heterocyclic compounds such as pyridine-ring-containing ones like 2,5-hydroxy-pyridine (DHP). 2,5-Dihydroxypyridine dioxygenase (NicX) from Pseudomonas putida KT2440 uses a mononuclear nonheme Fe(II) to catalyze the oxidative pyridine ring cleavage reaction by transforming DHP into N -formylmaleamic acid (NFM). Herein, we report a crystal structure for the resting form of NicX, as well as a complex structure wherein DHP and NFM are trapped in different subunits. The resting state structure displays an octahedral coordination for Fe(II) with two histidine residues (His 265 and His 318 ), a serine residue (Ser 302 ), a carboxylate ligand (Asp 320 ), and two water molecules. DHP does not bind as a ligand to Fe(II), yet its interactions with Leu 104 and His 105 function to guide and stabilize the substrate to the appropriate position to initiate the reaction. Additionally, combined structural and computational analyses lend support to an apical dioxygen catalytic mechanism. Our study thus deepens understanding of non-heme Fe(II) dioxygenases.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
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IF 4.539
Weifeng Li,Tao Zhang,Li Lv,Yanxiao Chen,Wenxiang Tang,Shengwei Tang
A novel strategy of room-temperature synthesis of MIL-100(Fe) with organic amine as deprotonating agent was proposed. The as-prepared solid product was denoted as R-MIL-100(Fe). The material was systematically characterized via XRD , FT-IR, XPS and SEM. The effects of operation parameters such as initial fluoride concentration, reaction time, initial pH and co-existing anions on the fluoride adsorption performance of the synthesized R-MIL-100(Fe) were studied. The maximum fluoride adsorption capacity of R-MIL-100(Fe) was as high as 23.53 mg/g at 298 K in the fluoride solution. The results indicate that the adsorption process of fluorine on R-MIL-100(Fe) belongs to surface adsorption and intraparticle diffusion . An excellent fluoride adsorption performance of R-MIL-100(Fe) was observed in a wide pH range of 4–10. The co-existing anions including Cl - , NO 3 - and SO 4 2- almost had no negative effects on the adsorption performance of R-MIL-100(Fe). However, the present of CO 3 2- or HCO 3 - brought an obvious reduction of F - adsorption capacity of R-MIL-100(Fe). Thermodynamic study results illustrate that the adsorption process was an exothermic chemisorption . Chemical combination of iron and fluorine was confirmed by FT-IR and XPS. The strong combination brings the excellent F - adsorption performance of MIL-100(Fe). R-MIL-100(Fe) was successfully regenerated and recycled five cycles with an excellent regeneration ability and recyclability.
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ACS Omega
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2021
·
IF 3.512
Binbin Jin,Ligang Luo,Longfei Xie
The utilization of CO2, as a cheap and abundant carbon source to produce useful chemicals or fuels, has been regarded as one of the promising ways to reduce CO2 emissions and minimize the green-house effect. Previous studies have demonstrated that CO2 (or HCO3–) can be efficiently reduced to formic acid with metal Fe under hydrothermal conditions without additional hydrogen and any catalyst. However, the pathways and kinetics of the autocatalytic CO2 reduction remain unknown. In the present work, the reaction kinetics were carefully investigated according to the proposed reaction pathways, and a phenomenological kinetic model was developed for the first time. The results showed that the hydrothermal conversion of HCO3– into formic acid with Fe can be expressed as the first-order reaction, and the activation energy of HCO3– is 28 kJ/mol under hydrothermal conditions.
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APPLIED SURFACE SCIENCE
·
2021
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IF 6.707
Cong Wang,Jingyu Zhao,Congmei Chen,Ping Na
In this study, we compared the differences between bimetallic oxides FeCo 2 O 4 catalyzing the oxidation of phenol by peroxydisulfate (PS) and peroxymonosulfate (PMS) under near neutral and alkaline conditions. Phenol could be completely oxidized and removed in both PMS and PS systems. X-ray photoelectron spectroscopy (XPS) analysis and density functional theory (DFT) calculations showed that there was a synergistic mechanism between Co and Fe on the catalyst surface. Although the PMS-FeCo 2 O 4 system reached the fastest reaction rate of 1.5 × 10 −1 min −1 , it showed a higher oxidants consumption and more residual total organic carbon (TOC) (36%) in solutions after reactions. Quenching experiments and electron paramagnetic resonance (EPR) analysis showed that sulfate radical (SO 4 − ), hydroxyl radical ( OH) and singlet oxygen ( 1 O 2 ) played important roles in the oxidation of phenol in PMS system. While in the PS-FeCo 2 O 4 system, in addition to free radical reactions, the non-radical mechanisms between PS and the catalyst surface played a major role in phenol oxidation, and the soluble organic matter in the PS system could be completely removed. Thus, PS has a better application prospect in the treatment of phenol. This discovery has certain guiding significance for catalyst modification and doping to improve catalyst activity and the choice of oxidant.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 31
·15252-15262
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IF 3.553
Jiang Xiaoli,He Miao,Tang Mengyi,Zheng Qiaoji,Xu Chenggang,Lin Dunmin
Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions has been considered as a promising approach for green ammonia synthesis; however, non-precious metal-based catalysts with excellent NRR electrocatalytic performance have been scarce. Herein, self-supported bimetallic electrocatalysts of Ni 12 P 5 /FeP 4 nanoplates grown on carbon cloth were synthesized by a combined process of hydrothermal technology and low-temperature phosphidation. The catalyst exhibits excellent electrocatalytic N 2 fixation performance with a high NH 3 yield rate of 3.08 × 10 −10 mol s −1 cm −2 (16.40 μg h −1 mg −1 cat
), Faradaic efficiency (39.9%) as well good durability at − 0.1 V in 0.1 M Na 2 SO 4 at ambient conditions, which are attributed to the distinctive nanostructure and rational composition. Our study paves the way for expanding the scope of NRR research and designing more efficient electrochemical ammonia synthesis in the future.
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Nano-Micro Letters
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2020
·Vol. 12
·期 1
·1-12
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IF 12.264
Xu Weiqing,Kang Yikun,Jiao Lei,Wu Yu,Yan Hongye,Li Jinli,Gu Wenling,Song Weiyu,Zhu Chengzhou
The two functional groups (nitro and amino) were introduced into MIL-101(Fe) for tuning the atomically dispersed metal active sites.
Benefiting from both geometric and electronic effects, the nitro-functionalized MIL-101(Fe) shows a superior electronic structure of active sites and low reaction energy barrier for the HO* formation.
Nitro-functionalized MIL-101(Fe)-based biosensor was successfully employed to detect acetylcholinesterase activity and organophosphorus pesticide.
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JOURNAL OF FLUORINE CHEMISTRY
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2020
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IF 2.332
Yongyang Chen,Dan Guo,Xiaochun Dong,Yahui Li,Yixuan Huang,Hao Chen,Shanping Li
Perfluorooctanoic acid (PFOA), as a refractory organic pollutant, seriously harms the environment and damages human health. Here, the electrocatalytic method was selected to degrade PFOA. In this work, perovskite catalysts doped with different elements, and corresponding gas diffusion electrodes (GDE) were prepared by the gel-sol method and citric acid complexation method. The crystal structure, microscopic morphology, and electrochemical properties of the LaNi x Y 1-x O 3 (Y = Fe, Cu, Co, Sr) perovskite catalyst electrode were analyzed by XRD, TEM, and CV. Moreover, the electrocatalytic performances of the as-prepared electrodes were assessed by the degradation of PFOA, and the Sr-doped GDE exhibited the highest degradation rate of PFOA. The optimum degradation conditions, such as the current density, pH, and initial concentration were also investigated. It was observed that when the current density was 20 mA/cm 2 , pH was 5, and initial concentration was 0.25 mmol/L, the Sr-doped GDE had the best degradation and defluorination efficiency of PFOA reached 90.0 % and 75.1 %, respectively. High performance liquid chromatography-mass spectrometry (HPLC-MS) was used to analyze the intermediate products of PFOA degradation and obtain the degradation pathway. With the combined action of OH and O 2 , PFOA was degraded by stepwise removal of CF 2 groups, which were ultimately degraded into F − and CO 2 .
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CATALYSIS TODAY
·
2020
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IF 5.825
Fei Yuan,Guanghui Zhang,Jie Zhu,Fanshu Ding,Anfeng Zhang,Chunshan Song,Xinwen Guo
Direct conversion of carbon dioxide (CO 2 ) into lower olefins (C 2 -C 4 = ) is highly attractive as a sustainable production route for its great significance in greenhouse gas emission control and fossil fuel substitution. Fe-based catalysts have been extensively studied in CO 2 hydrogenation, which usually show unsatisfactory selectivity toward lower olefins. Here we present a high-dispersion catalyst precursor CoFe 2 O 4 with Na (Na-CoFe 2 O 4 ) that offers C 2 -C 4 = space time yield as high as 2.88 μmol C2-C4= g cat −1 s -1 and olefin to paraffin ratio about 6 at CO 2 conversion higher than 41 %. High dispersion and the intimate contact between Fe and Co sites help inhibit the formation of methane, and favor a higher selectivity of C 2 + hydrocarbons, especially lower olefins. The presence of Na further promotes chain growth and suppresses the direct hydrogenation of Fe-(CH 2 ) n intermediates. A superior stability over 100 h was observed, demonstrating the promising potential of this catalyst for industrial applications.
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ANALYTICA CHIMICA ACTA
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2020
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IF 5.977
Fa-Ting Xie,Xiao-Lan Zhao,Kuan-Neng Chi,Tong Yang,Rong Hu,Yun-Hui Yang
A ratiometric electrochemical aptasensor is proposed for the detection of thrombin. In the sensor, the iron metal-organic frameworks (Fe MOFs)-labeled aptamer as signal tags was used as signal probe (SP), and the electrolyte solution [Fe(CN) 6 ] 3-/4- was utilized as an inner reference probe (IR). In the presence of thrombin, the signal of Fe-MOFs can be detected. Meanwhile, the signal of [Fe(CN) 6 ] 3-/4 -IR almost remains stable. Accordingly, thrombin concentration can be monitored with the ratio response of I Fe-MOFs-SP /I [Fe(CN)6] 3-/4- -IR . The proposed ratiometric biosensor owns a strong ability to eliminate the disturbance that arises from different DNA loading densities, environmental impact and instrumental efficiency. DNA nanotetrahedron (NTH) with three-dimensional (3D) scaffold can effectively eliminate nonspecific adsorption of DNA and protein. The accessibility of target molecules and loading amounts of signal substances could be increased because of the enhanced mechanical rigidity of well-designed 3D NTH. Thus, detection reproducibility and sensitivity can be further improved. Moreover, the biosensor only requires conjugation with one electroactive substance. The modification procedure can be greatly simplified. The biosensor owns high sensitivity with the detection limit of 59.6 fM. We expect that it will emerge as a generalized ratiometric sensor that may be useful for detecting target analytes .
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