Hematite facet-mediated microbial dissimilatory iron reduction and production of reactive oxygen species during aerobic oxidation

摘要: Microbial dissimilatory iron reduction and aerobic oxidation affect the biogeochemical cycles of many elements. Although processes have been widely studied, underlying mechanisms, especially how surface structures oxides these redox processes, are poorly understood. Therefore, {001} facet-dominated hematite nanoplates (HNP) {100} nanorods (HNR) were used to explore effects structure on microbial processes. During stage, production total Fe(II) normalized by specific area (SSA) was higher for HNP than HNR due steric ligand-bound conformation connection between different exposed facets electron donors from microorganisms. However, during both SSA- Fe(II)-normalized reactive oxygen species (ROS), including hydrogen peroxide (H2O2) hydroxyl radical (•OH), HNP. Theoretical calculation results showed that exhibited a lower activation energy barrier reaction facets, supporting experimental observation had ROS efficiency These indicated characteristics not only mediated Fe(III) but also affected microbially reduced Fe(II). Accessibility atom determined Fe(III), dominated This study advances our understanding mechanisms through which produced (oxyhydr)oxides