A Density Functional Theory study of the chemical surface modification of β-SiC nanopores

Calvino, M.; Trejo, Alejandro; Cuevas, J.L.; Carvajal, E.; Duchen, Gonzalo; Cruz‐Irisson, M.

doi:10.1016/j.mseb.2012.02.009

Cited by 7 publications

(4 citation statements)

References 24 publications

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“…These states are most likely due to the extra p orbitals introduced by the O atoms. In comparison with our previous results [ 13 ], we see a similar behavior in the electronic band gap in the mixed Si and C surface scheme as in the bridge-bonded case. However, some key differences exist, such as the irregular changes in the band gap caused by a change in the chemical environment during the geometry optimization.…”

Section: Discussionsupporting

confidence: 88%

“…The porous structures were modeled using the supercell scheme described elsewhere [ 13 ], where Si and C atoms were removed in the [001] direction of an otherwise perfect 3C-SiC crystal. The porosity (p) was defined as the ratio between the removed atoms and the original number of atoms in the supercell.…”

Section: Methodsmentioning

confidence: 99%

“…For example, in our previous work [ 12 ], we addressed the effects of quantum confinement and, to a lesser scale, the effect of the C or Si richness in the surface of H-terminated pSiC on the electronic structure. In addition, we studied the effect of oxygen (O) atoms on the surface passivation of pSiC with mixed surface configurations [ 13 ]. However, we did not perform a detailed study on the effects of O at the pSiC surface with only C or Si atoms, or a study on the difference between a bridge bond (X-O-X, X = Si or C) and an O double bond at the surface of the pores.…”

Section: Introductionmentioning

confidence: 99%

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Computational simulation of the effects of oxygen on the electronic states of hydrogenated 3C-porous SiC

et al. 2012

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A computational study of the dependence of the electronic band structure and density of states on the chemical surface passivation of cubic porous silicon carbide (pSiC) was performed using ab initio density functional theory and the supercell method. The effects of the porosity and the surface chemistry composition on the energetic stability of pSiC were also investigated. The porous structures were modeled by removing atoms in the [001] direction to produce two different surface chemistries: one fully composed of silicon atoms and one composed of only carbon atoms. The changes in the electronic states of the porous structures as a function of the oxygen (O) content at the surface were studied. Specifically, the oxygen content was increased by replacing pairs of hydrogen (H) atoms on the pore surface with O atoms attached to the surface via either a double bond (X = O) or a bridge bond (X-O-X, X = Si or C). The calculations show that for the fully H-passivated surfaces, the forbidden energy band is larger for the C-rich phase than for the Si-rich phase. For the partially oxygenated Si-rich surfaces, the band gap behavior depends on the O bond type. The energy gap increases as the number of O atoms increases in the supercell if the O atoms are bridge-bonded, whereas the band gap energy does not exhibit a clear trend if O is double-bonded to the surface. In all cases, the gradual oxygenation decreases the band gap of the C-rich surface due to the presence of trap-like states.

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Section: Discussionsupporting

confidence: 88%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Computational simulation of the effects of oxygen on the electronic states of hydrogenated 3C-porous SiC

et al. 2012

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“…The method of slip casting prepares recrystallized silicon carbide ceramics, which has high density and dispersibility, low cost, and easy control, thus attracting widespread attention 6–8 . The premise of the slip casting method was to prepare a slurry with high solid content, low viscosity, and good dispersion performance 9–12 . However, superfine silicon carbide powder have a smaller particle size, usually micron, nanometer size, and have a high surface energy, resulting in a very easy agglomeration of the powder 13,14 .…”

Section: Introductionmentioning

confidence: 99%

Dispersibility of pretreated polyacrylic acid‐modified SiC powder

Sun

Niu

Liu

et al. 2020

Int J Applied Ceramic Tech

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A slurry with high dispersibility is crucial for slip casting technology. The weakly acidic SiC powder with high dispersibility was prepared with polyacrylic acid pretreated by the sodium hydroxide (adjusted pH = 5). The pretreated polyacrylic acid can be effectively adsorbed on the surface of SiC powder, and its utilization efficiency (37%) was better than the unpretreated one (21%). The modified SiC powder with pH = 6 was obtained by polyacrylic acid modification, and the maximum solid content was 61.2 Vol%. The optimum of the pretreated polyacrylic acid addition amount was 1 wt% based on Zeta potential, solid content, and viscosity analysis data. Compared with the unmodified SiC, the Zeta potential absolute value of the modified (−63 mV) was higher due to a large amount of anionic modifier adsorbed on particle surfaces. The modified SiC slurry was more stable because the modification increases the electrostatic repulsion among the SiC molecules.

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Surface morphology effects on the mechanical and electronic properties of halogenated porous 3C-SiC: A DFT study

Bermeo-Campos

Madrigal-Carrillo

Pérez-Figueroa

et al. 2023

Applied Surface Science

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A Density Functional Theory study of the chemical surface modification of β-SiC nanopores

Cited by 7 publications

References 24 publications

Computational simulation of the effects of oxygen on the electronic states of hydrogenated 3C-porous SiC

Computational simulation of the effects of oxygen on the electronic states of hydrogenated 3C-porous SiC

Dispersibility of pretreated polyacrylic acid‐modified SiC powder

Surface morphology effects on the mechanical and electronic properties of halogenated porous 3C-SiC: A DFT study

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