A highly reactive precursor in the iron sulfide system

Abstract

Iron sulfur (Fe–S) phases have been implicated in the emergence of life on early Earth due to their catalytic role in the synthesis of prebiotic molecules. Similarly, Fe–S phases are currently of high interest in the development of green catalysts and energy storage. Here we report the synthesis and structure of a nanoparticulate phase (FeSnano) that is a necessary solid-phase precursor to the conventionally assumed initial precipitate in the iron sulfide system, mackinawite. The structure of FeSnano contains tetrahedral iron, which is compensated by monosulfide and polysulfide sulfur species. These together dramatically affect the stability and enhance the reactivity of FeSnano.

Molecular‐Level Design of Pyrrhotite Electrocatalyst Decorated Hierarchical Porous Carbon Spheres as Nanoreactors for Lithium–Sulfur Batteries

“…[ 46 ] The Fe 2p 3/2 component is decomposed into 4 peaks at 709, 710.5, 712.1, and 714.1 eV, respectively. The binding energies (BEs) at 709, 710.5, and 712.1 eV can be attributed to the Fe 3+ state, bound to S species, [ 47,48 ] while the high BE at 714.1 eV could be due to Fe 3+ bound to longer chained polysulfides (S n 2− ) having larger electronegativity [ 49 ] or Fe 2 (SO 4 ) 3 . [ 48,50 ] The energy separation between the Fe 3+ 2p 3/2 shake‐up satellite peak and the Fe 2p 3/2 main peak (∆ E ) indicates the type of ligand associated with Fe 3+ , [ 46 ] i.e., as the electronegativity of the ligand decreases, so does the ∆ E .…”

“…The S 2p component could be decomposed into three main peaks at 161.3, 163.8, and 167.8 eV, which were attributed to S 2− , S n 2− , and possibly SO 4 2− , respectively. [ 47,48,51 ] The decomposed high‐resolution XPS of C 1s, O 1s, and N 1s for Fe 1− x S‐NC are presented in Figure S8a–c in the Supporting Information, respectively. It is noteworthy to point out that the signal for Fe–N x species, typically at BE of around 399 eV [ 52,53 ] was not observed on the N 1s XPS for Fe 1− x S‐NC (Figure S8c, Supporting Information).…”

Formation of diagenetic siderite in modern ferruginous sediments

“…We suggest that the carbonate GR and magnetite form in the upper reaches of the sediments or bottom water and become trapped in siderite interstices during its initial formation (Bell et al, 1987). Chemical micro-niches, such as the pore spaces within siderite, are known to preserve redoxsensitive minerals on geological time scales (Matamoros-Veloza et al, 2018), and trapping in siderite could preserve and shield these mineral grains preventing their further reaction with pore fluids during burial. Fabrics observed in lattice fringes may further suggest epitaxial growth of siderite on carbonate GR (Fig.…”

“…This stands in contrast to carbonate GR instability in laboratory experiments, even at hourly time scales (Ruby et al, 2010;Guilbaud et al, 2013;Halevy et al, 2017). GR is known to rapidly convert into an amorphous ferric oxyhydroxycarbonate under standard conditions, or to more stable phases such as goethite and lepido crocite (Legrand et al, 2004). Alternatively, carbonate GR could form through reaction with oxygen during sample exposure to the atmosphere (Tamaura et al, 1984).…”

Facile Synthesis of Sulfur‐Containing Transition Metal (Mn, Fe, Co, and Ni) (Hydr)oxides for Efficient Oxygen Evolution Reaction

“…The reaction of S 2À with transition metal ions or transition metal (hydr)oxide led to the formation of sulfurcontaining species. [31][32][33][34][35][36] While XPS confirms the presence of sulfide groups, no crystalline sulfur containing phases could be observed by XRD. With this method, we simplified the complex multistep synthesis of MO a S b into a facile one-step method overcoming the need for high temperature sulfurization.…”