Journal of Environmental Sciences
·
2021
·
IF 5.565
Ji Li,Chenlu Shi,Wenbin Zeng,Yaru Wang,Zebin Hong,Yibing Ma,Liping Fang
Electron shuttles such cysteine play an important role in Fe cycle and its availability in soils, while the roles of pH and organic ligands in this process are poorly understood. Herein, the reductive dissolution process of goethite by cysteine were explored in the presence of organic ligands. Our results showed that cysteine exhibited a strong reactivity towards goethite – a typical iron minerals in paddy soils with a rate constant ranging from 0.01 to 0.1 hr −1 . However, a large portion of Fe(II) appeared to be “structural species” retained on the surface. The decline of pH was favorable to generate more Fe(II) ions and enhancing tendency of Fe(II) release to solution. The decline of generation of Fe(II) by increasing pH was likely to be caused by a lower redox potential and the nature of cysteine pH-dependent adsorption towards goethite. Interestingly, the co-existence of oxalate and citrate ligands also enhanced the rate constant of Fe(II) release from 0.09 to 0.15 hr −1 ; nevertheless, they negligibly affected the overall generation of Fe(II) in opposition to the pH effect. Further spectroscopic evidence demonstrated that two molecules of cysteine could form disulfide bonds (S-S) to generate cystine through oxidative dehydration, and subsequently, inducing electron transfer from cysteine to the structural Fe(III) on goethite; meanwhile, those organic ligands act as Fe(II) “strippers”. The findings of this work provide new insights into the understanding of the different roles of pH and organic ligands on the generation and release of Fe induced by electron shuttles in soils.
研究领域:
土壤科学
·
环境化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Nano
·
2023
·
IF 7.3
Ruixue Wang,Kun Li,Narcisse Tsona Tchinda,Wenxing Wang,Lin Du
Ammonia (NH3), the most common alkaline gas in the atmosphere, participates in heterogeneous reactions on the surface of aerosols and produces ammonium (NH4+). While most previous studies have focused on the effect of NH3 on the heterogeneous reactions of other gases on mineral dust aerosols, little research has been done on the heterogeneous reactions of NH3 influenced by acidic gases. Here, the effects of sulfur dioxide (SO2), formic acid, acetic acid and acrylic acid on the heterogeneous reaction of NH3 on the surface of nano α-Fe2O3 particles were investigated. We found that NH3 can promote the dissolution of α-Fe2O3 through NH3–Fe complexation and be oxidized to NO3−, while the addition of acidic gas inhibits the NH3–Fe complex formation and converts it into physical adsorption. SO2 promoted the conversion of NH3 to NH4+, while weakly inhibiting the oxidation of NH3 to NO3− by competing for oxidation sites under light conditions. Organic acids, on the other hand, inhibited the heterogeneous conversion of NH3, and strongly competed for oxidation sites under light conditions, significantly reducing NO3− production. This study reveals the various influences of acidic gases on NH3 heterogeneous reactions on α-Fe2O3 particles, which helps to improve the understanding of atmospheric processes involving NH3, acidic gases, and mineral dust aerosols.
研究领域:
大气化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Hanxiao Liao,Kejun Chen,Xin Wang,Feng Liu,Xiaorong He,Jiaxin Tong,Pengfei Tan,Xueyi Guo,Jun Pan
Nickel–iron (NiFe) materials with flexible structure and component have shown all-right potency for the alkaline oxygen evolution reaction (OER) due to their low reaction barriers. However, most of NiFe catalysts suffer from inferior electrocatalytic stability induced by unfavorable Fe dissolution. Herein, the selective sulfuration of FeOOH/Ni(OH) 2 (NiFe) is developed to construct a reliable Fe─S interaction in FeOOH/Ni 3 S 2 /Ni(OH) 2 (NiFeS) composite and subsequently restrain the Fe dissolution, realizing durable OER stability. X-ray absorption spectroscopy and theoretical calculations demonstrate that the strong Fe─S interaction affords more electrons to metal sites, thereby stabilizing Fe sites. Meanwhile, the tailored Fe sites with shortened interatomic distance are conducive to inducing double lattice oxygen mechanism (dLOM) for further improving OER activity. Consequently, NiFeS displays a seven-fold improvement of OER stability and a decreased overpotential compared to NiFe. Moreover, the anion exchange membrane water electrolysis (AEMWE) cell using NiFeS as anode presents an impressive durability for 300 h with negligible attenuation of 0.26 mV h ─1 at 1.0 A cm ─2 at 60 °C. This work provides a new approach to conquer the Fe leakage in NiFe catalysts and enhance the catalytic stability, escorting for their industrial application.
研究领域:
材料科学
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电化学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2021
·Vol. 8
·期 3
·698-710
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IF 8.131
Kejian Li,Xiaozhong Fang,Tao Wang,Kedong Gong,Muhammad Ali Tahir,Wei Wang,Jin Han,Hanyun Cheng,Guanjun Xu,Liwu Zhang
Water-soluble low-molecular-weight dicarboxylic acids (DCAs) and corresponding salts are ubiquitous in the atmosphere. They could efficiently form chelates with iron in atmospheric particles, which could be photoexcited to generate a series of strong oxidants, and have profound impacts on atmospheric chemistry. However, the influences of iron–DCAs complexes on the heterogeneous uptake of atmospheric trace gases are unclear. In this study, the effects of dominant dicarboxylic acid salts (including oxalate, malonate, and succinate) on the heterogeneous SO2 conversion with hematite nanoparticles were systematically investigated using film flow reaction and in situ DRIFTs experiments. It was found that a trace amount of DCA salts could significantly accelerate sulfate formation under solar light illumination. Additionally, similar results were also observed on the Arizona test dust, a proxy of authentic mineral dusts. Moreover, the iron solubility was increased owing to the effects of oxalate complexation, especially under light irradiation. Furthermore, the reaction mechanisms for the enhanced SO2 uptake and iron dissolution in the presence of DCA salts were proposed, and atmospheric environmental implications were discussed.
研究领域:
环境科学
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大气化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2019
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IF 7.149
Xiao-Cheng Liu,Wen-Qiang Li,Yi-Ran Wang,Guan-Nan Zhou,Yi-Xuan Wang,Chuan-Shu He,Gong-Ming Wang,Yang Mu
Promotion of iron solubility using ligands is the preliminary step in the homogeneous electro-Fenton (EF) process at a mild pH, but the chelate efficiencies of most organic ligands are unsatisfactory, resulting in insufficient Fe(II) availability. In this study, atomic H* was, for the first time, introduced to the EF process to accelerate the regeneration of the Fe(II)-complex at a mild pH using a Ni-deposited carbon felt (Ni-CF) cathode. The introduction of atomic H* significantly elevated total organic carbon (TOC) abatement of ciprofloxacin (CIP) from 42% (CF) to 81% (Ni-CF) at a natural pH. In the presence of humic acids (HAs), atomic H* introduced via Ni-CF enhanced the CIP degradation rate to 10 times that of the CF at a mild pH. The electron spin resonance (ESR), density functional theory (DFT) calculations, electrochemical characterization, and in situ electrochemical Raman study clearly demonstrated that the atomic H* generated from the Ni-CF cathode was highly efficient at reducing Fe(III)-complexes at a natural pH. Additionally, the Ni-CF could generate atomic H* without significant nickel leaching. Thus, the atomic H* could continuously facilitate iron cycling and, consequently, enhance pollutant mineralization via the homogeneous EF process at a mild pH in an environmentally friendly manner.
研究领域:
环境科学
·
化学工程
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水处理
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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