Molecular Environmental Biogeochemistry Group

Li X, Qin F, Chen X, Sheng A, Wang Z, Liu J. Dissolution Behavior of Isolated and Aggregated Hematite Particles Revealed by in Situ Liquid Cell Transmission Electron Microscopy. Environmental Science & Technology [Internet]. 2019. 访问链接

Peng H, Pearce CI, N'Diaye AT, Zhu Z, Ni J, Rosso KM, Liu J. Redistribution of Electron Equivalents between Magnetite and Aqueous Fe²⁺ Induced by a Model Quinone Compound AQDS. Environmental Science and Technology [Internet]. 2019. 访问链接

刘娟∗, 盛安旭, 刘枫, 李晓旭, 琚宜文*, 刘国恒. 纳米矿物及其环境效应. 地球科学. 2018;43(5):1450-1463.

Peng H, Pearce CI, Huang W, Zhu Z*, N’Diaye AT, Rosso KM, Liu J*. Reversible Fe(II) uptake/release by magnetite nanoparticles. Environmental Science: Nano. Environmental Science: Nano [Internet]. 2018. 访问链接

You Y, Zheng S, Zang H, Liu F, Liu F, Liu J*. Stimulatory effect of magnetite on the syntrophic metabolism of Geobacter co-cultures: Influences of surface coating. Geochimica et Cosmochimica Acta [Internet]. 2018. 访问链接 Abstract

Magnetite-mediated direct interspecies electron transfer (DIET) can facilitate syntrophic metabolism in natural microbial communities and also promote the performance of the engineered systems based on syntrophic interactions. In this study, the stimulatory effect of bare synthetic magnetite (Mt), humic acid coated magnetite, and SiO2 coated magnetite (Mt-SiO2) on DIET in defined co-cultures of Geobacter metallireducens/Geobacter sulfurreducens were studied. Magnetite coated with Aldrich humic acid (HA) and Elliott Soil humic acid (HAES), respectively, were prepared, and the two kinds of humic acid influenced the ability of Mt to promote syntrophic metabolism of the co-cultures in a similar way. When weight concentration was the same, pure humic acid presented the stimulatory effect on DIET similar to bare magnetite. However, the presence of HA coating on magnetite surface caused 50% and 61%, respectively, decrease in the rates of ethanol consumption (Re) and succinate production (Rs) in DIET processes. Pure HA in the same weight concentration as the HA coating in Mt-HA induced the similar metabolism rates as Mt-HA. In the Mt-HA mediated DIET, most electrons from ethanol metabolism were transferred to G. sulfurreducens selectively through the HA coating, and magnetite core hardly contributed to DIET processes. The SiO2 coating on magnetite resulted in 81% and 89%, respectively, decreases in Re and Rs, mainly because the non-conductive SiO2 layer hindered electron transfer between magnetite core and bacteria. After eight-day incubation with the co-cultures, bare magnetite nanoparticles formed relatively larger and more compact aggregates with cells than Mt-HA and Mt-SiO2, due to the different surface charge between bare and coated Mt. The generation of dissolved Fe(II) and HCl-extractable Fe(II) due to microbial reduction of magnetite by G. metallireducens and vivianite formation were observed along with DIET processes in all DIET experiments. Based on these results, different pathways of electron transfer in defined co-cultures of Geobacters with bare and coated magnetite nanoparticles were proposed. The findings in this study demonstrate the significant effects of surface properties on the ability of magnetite to stimulate DIET, which needs to be considered in order to comprehensively understand the role and mechanisms of mineral-mediated DIET in natural and engineered systems.

Zang H, Miao C, Shang J, Liu Y, Liu J*. Structural effects on the catalytic activity ofcarbon-supported magnetite nanocomposites inheterogeneous Fenton-like reactions. RSC Adv [Internet]. 2018. 访问链接 Abstract

The catalytic reactivity of synthetic bare magnetite nanoparticles, activated carbon supported magnetite (AC-Mt), and graphene oxide supported magnetite (GO-Mt) for heterogeneous Fenton-like oxidation of methylene blue (MB) were compared, in order to investigate how the structural features of the support impact catalytic activity of the nanocomposites. The different effects of AC and GO on MB removal rate, hydroxyl radical ([radical dot]OH) production, iron leaching, and surface deactivation have been systematically studied. The rate constant of MB removal by AC-Mt was 0.1161 min-1, one order of magnitude larger than the value of bare magnetite nanoparticles (0.0566 min-1). The higher catalytic activity of AC-Mt might be attributed to the larger reactive surface area of well-dispersed magnetite for [radical dot]OH production and the recharge of the magnetite surface by the AC support via Fe-O-C bonds. However, the removal rate of MB by GO-Mt was one order of magnitude slower than that of bare magnetite nanoparticles under the same experimental conditions, presumably due to the wrapping of GO around magnetite nanoparticles or extensive aggregation of GO-Mt composites. These findings revealed the significant influence of support structure on the catalytic activity of carbon-supported magnetite nanocomposites, which is important for the development of efficient magnetite-based catalysts for wastewater treatments.

Redistribution of Electron Equivalents between Magnetite and Aqueous Fe2+ Induced by a Model Quinone Compound AQDS

Dissolution Behavior of Isolated and Aggregated Hematite Particles Revealed by in Situ Liquid Cell Transmission Electron Microsc

Reversible Fe(II) uptake/release by magnetite nanopartocles

Stimulatory effect of magnetite on the syntrophic metabolism of Geobacter co-cultures

Enhanced photocurrent production by the synergy of hematite nanowire-arrayed photoanode and bioengineered Shewanella oneidensis

Extracellular electron transfer mechanisms between microorganisms and minerals

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