Surface states and reactivity of pyrite and marcasite

Uhlig, I.; Szargan, R.; Nesbitt, H.W.; Laajalehto, K.

doi:10.1016/s0169-4332(01)00283-5

Cited by 185 publications

(97 citation statements)

References 23 publications

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“…The surface properties of cleaved surfaces of binary semiconductors having the sphalerite structure extensively studied over the past few decades (Hinkel et al 1988, Eastman et al 1980, Leiro et al 1998, Nesbitt et al 1998, 2002, Uhlig et al 2001, Biegelsen et al 1990a, b, Pashley et al 1988, Kaxiras et al 1986, Nakada & Osaka 1991. However, few studies of ternary semiconductors have been performed.…”

Section: Previous Studiesmentioning

confidence: 99%

“…Owing to spectral broadening, identifi cation of the surface contributions in the S 2p spectra of bornite is not as straightforward as in other sulfi des (Harmer et al 2004, Harmer & Nesbitt 2004, Nesbitt et al 1998, Schaufuss et al 1998a, Uhlig et al 2001. Thus, an alternative approach to the spectral fi tting is required.…”

Section: Spectral Fi Tmentioning

confidence: 99%

“…Consequently, similar core-level shifted peaks should be observed on the high-binding-energy side of the Cu 2p and Fe 2p signals, representing surface cations with lower electron-density than the fully coordinated bulk cations. Surface core-level shifts have been observed in a variety of semiconducting compounds, including InSb (Hinkel et al 1988), GaSb (Eastman et al 1980), PbS (Leiro et al 1998), FeS 2 (pyrite and marcasite, Nesbitt et al 1998, Uhlig et al 2001, Fe 1-x S (pyrrhotite), NiS (millerite, Nesbitt et al 2001) and CuFeS 2 (Harmer et al 2004).…”

Section: Origin Of the Surface Monomermentioning

confidence: 99%

“…The broad nature of the contribution may suggest the presence of longer oligomer chains, possibly trimers or tetramers. Surface polymeric species have been observed on a variety of mineral surfaces including chalcopyrite (Harmer et al 2004) and löllingite (Uhlig et al 2001). The implication is that the sulfur-rich surface has undergone reconstruction.…”

Section: Origin Of the Surface Polymersmentioning

confidence: 99%

“…This is the lowest energy state for such a surface, and is indicated by a surface core-level shift in XPS spectra. Surface core-level shifts have been observed in a variety of covalent chalcogenides and other semiconductors, including InSb (Hinkel et al 1988), GaSb (Eastman et al 1980), PbS (Leiro et al 1998), FeS 2 (pyrite and marcasite, Nesbitt et al 1998, Uhlig et al 2001, Fe 1-x S (pyrrhotite), NiS (millerite, Nesbitt et al 2001), CuFeS 2 (Harmer et al 2004) and have been associated with autocompensated surfaces. The bornite structure has few surfaces that contain both cations and anions, such as the (011) and the (110) planes.…”

Section: Fracture Surfaces and Reconstructionmentioning

confidence: 99%

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Reconstruction of Fracture Surfaces on Bornite

Harmer¹,

Pratt²,

Nesbitt³

et al. 2005

The Canadian Mineralogist

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Synchrotron-radiation X-ray Photoelectron Spectroscopy (SRXPS) and conventional X-ray Photoelectron Spectroscopy (XPS) have been used to study a pristine fracture-surface of bornite (Cu 5 FeS 4 ). Comparisons of these high-resolution spectra reveal, for the fi rst time, four distinct contributions to the S 2p spectra. The main symmetric peak of the S 2p spectra for bornite is located at about 163.51 eV and is derived from bulk S atoms. The broad nature of the bulk contribution, in comparison to other 3d transition-metal sulfi des such as chalcopyrite, is consistent with the presence of eight crystallographically distinct S sites within the structure, these sites being energetically as well as structurally distinct. A second peak located at 160.1 eV is attributed to a surface monomeric species (S 2-) of lower coordination. The presence of a second broad surface-contribution at 162.1 eV likely represents surface polymeric species (S n 2-). The presence of surface sulfur polymers indicates the stabilization of the bornite surface upon fracture through formation of S-S bonds. These data suggest that surface polymers form where polar surfaces are exposed during conchoidal fracture. A high binding-energy tail was observed at about 163 eV and extends to about 166 eV, the origin of which is uncertain. Conventional XPS Cu 2p and Fe 2p spectra collected from a pristine fracture-surface of bornite reveal a Cu 1+ peak centered at about 932.2 eV and a high-spin Fe 3+ peak centered at 708 eV.Keywords: X-ray photoelectron spectroscopy, bornite, sulfi des, iron, copper, surface speciation. SOMMAIRENous avons utilisé la spectroscopie photo-électronique des rayons X en rayonnement synchrotron (SRXPS) et la spectroscopie photo-électronique des rayons X conventionnelle (XPS) pour étudier une surface fracturée très fraiche de la bornite (Cu 5 FeS 4 ). A la suite de comparaisons de ces spectres à résolution élevée, nous démontrons pour la première fois quatre contributions distinctes au spectre de l'atome S 2p. Le pic symétrique principal du spectre de S 2p de la bornite est situé à environ 163.51 eV, et il est dérivé de la masse globale des atomes de S. La nature généralisée de cette contribution globale, par rapport aux autres sulfures de métaux de transition 3d tels la chalcopyrite, concorde avec la présence de huit sites S cristallographiquement distincts dans la structure, tous ces sites étant aussi énergétiquement et structuralement distincts. Un second pic situé à 160.1 eV est attribuable à une espèce de surface monomérique (S

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Section: Previous Studiesmentioning

confidence: 99%

Section: Spectral Fi Tmentioning

confidence: 99%

Section: Origin Of the Surface Monomermentioning

confidence: 99%

Section: Origin Of the Surface Polymersmentioning

confidence: 99%

Section: Fracture Surfaces and Reconstructionmentioning

confidence: 99%

See 3 more Smart Citations

Reconstruction of Fracture Surfaces on Bornite

Harmer¹,

Pratt²,

Nesbitt³

et al. 2005

The Canadian Mineralogist

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Highly Efficient and Stable Saline Water Electrolysis Enabled by Self‐Supported Nickel‐Iron Phosphosulfide Nanotubes With Heterointerfaces and Under‐Coordinated Metal Active Sites

Martin‐Diaconescu

et al. 2022

Adv Funct Materials

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Direct seawater electrolysis is proposed as a potential low-cost approach to green hydrogen production, taking advantage of the vastly available seawater and large-scale offshore renewable energy being deployed. However, developing efficient, earth-abundant electrocatalysts that can survive under harsh corrosive conditions for a long time is still a significant technical challenge. Herein, the fabrication of a self-supported nickel-iron phosphosulfide (NiFeSP) nanotube array electrode through a two-step sulfurization/phosphorization approach is reported. The as-obtained NiFeSP nanotubes comprise abundant NiFeS/NiFeP heterointerfaces and under-coordinated metal sites, exhibiting outstanding activity and durability for the hydrogen and oxygen evolution reactions (HER and OER) in simulated alkaline-seawater solution (KOH + NaCl), with an overpotential of 380 (HER) and 260 mV (OER) at 500 mA cm -2 and outstanding durability of 1000 h. Theoretical calculations support the observed outstanding performance, showing that the heterointerface and under-coordinated metal sites synergistically lower the energy barrier of the rate-determining step reactions. The NiFeSP electrode also shows good catalytic performance for the urea oxidation reaction (UOR). By coupling UOR with HER, the bifunctional NiFeSP electrode pair can efficiently catalyze the overall urea-mediated alkaline-saline water electrolysis at 500 mA cm -2 under 1.938 V for 1000 h without notable performance degradation.

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A Magnetic Cloud Bomb for Effective Biofilm Eradication

Qian

Zhang

et al. 2023

Adv Funct Materials

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Skin and soft tissue infection (SSTI) is an inflammatory condition caused by bacteria, and the eradication of biofilms is an important problem when treating such infections. Because of the low dispersibility and biofilm permeability of magnetic antibacterial materials, biofilm removal is difficult and infection persists. To solve these problems, inspired by conventional cloud bombs, a magnetic “nano‐cloud bomb” by adjusting the synthesis ratio to alter the shape of an assembled zeolitic imidazolate framework (ZIF), namely ZIF‐L‐Fe, is synthesized simply and rapidly. ZIF‐L‐Fe has a flower‐like clustered structure with sharp edges, which prevents the stacking of 2D ZIF nanoleaves, thereby enhancing the dispersion of Fe nanoparticles and increasing biofilm penetration under the action of magnetism. Additionally, ZIF‐L‐Fe retains the photothermal and catalytic properties of nanoparticles, which can kill methicillin‐resistant Staphylococcus aureus (MRSA) at low temperature and efficiently catalyze hydrogen peroxide (H2O2). Because of its magnetic effect, ZIF‐L‐Fe can rapidly penetrate biofilm, thus forming craters and destroying the local biofilm structure. Accordingly, the proposed strategy of clustered ZIF‐loaded delivery of Fe provides a novel concept that requires further development for clinical application to the treatment of biofilm infections.

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Surface states and reactivity of pyrite and marcasite

Cited by 185 publications

References 23 publications

Reconstruction of Fracture Surfaces on Bornite

Reconstruction of Fracture Surfaces on Bornite

Highly Efficient and Stable Saline Water Electrolysis Enabled by Self‐Supported Nickel‐Iron Phosphosulfide Nanotubes With Heterointerfaces and Under‐Coordinated Metal Active Sites

A Magnetic Cloud Bomb for Effective Biofilm Eradication

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