Spatial distribution of manganese oxide minerals in the natural ferromanganese nodule of the Arctic Sea: A view from Raman spectroscopy

Understanding the role of manganese oxides in retaining harmful metals: Insights into oxidation and adsorption mechanisms at microstructure level

“…Todorokite, a prominent Mn mineral found in marine ferromanganese nodules and crusts [ 37 , [124] , [125] , [126] ], is characterized by its tunnel structure composed of triple chains of edge-sharing Mn(IV)O 6 octahedra that are corner-shared with adjacent triple octahedral chains. This arrangement results in a 3 × 3 tunnel structure, providing a significant tunnel cavity per unit cell measuring 6.9 × 6.9 Å [ 29 , 123 , 127 , 128 ].…”

“…[ 102 ] proposed a four-stage mechanism for this conversion. Furthermore, recent research also indicates that todorokite predominantly occurs in deeply buried nodules, suggesting that phyllomanganates can transform into todorokite under relatively suboxic conditions as well [ 126 , 132 ].…”

Terahertz Time-Domain Spectroscopic Characteristics of Typical Metallic Minerals

“…Various chemical-physical methods apply to the spectral characterization of rocks and metallic minerals, such as X-ray analysis [7], thermogravimetric analysis [8,9], scanning electron microscope [10], Raman spectroscopy [11], mass spectrometry [12], etc. [13,14] These methods primarily serve as qualitative or semi-quantitative research tools.…”