Tunable band gap and magnetism of the two-dimensional nickel hydroxide

Tang, Zhen‐Kun; Liu, Weiwei; Zhang, Deng-Yu; Lau, Woon‐Ming; Liu, Limin

doi:10.1039/c5ra10380k

Cited by 25 publications

(12 citation statements)

References 47 publications

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“…However, significant magnetism is rarely observed in experiment due to the delocalization of s and p orbitals in carbon materials. Alternatively, 2D inorganic graphene-like crystals, such as transition metal dichalcogenides, − oxides, − nitrides, , carbide, − halide, , silicide, − and complex ternary compounds, − present great opportunities in spintronics applications for the possible existence of d orbital itinerant magnetism transition metal atoms and coupling between them.…”

Section: Methodsmentioning

confidence: 99%

Room-Temperature Ferromagnetism in Two-Dimensional Fe₂Si Nanosheet with Enhanced Spin-Polarization Ratio

et al. 2017

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Searching experimental feasible two-dimensional (2D) ferromagnetic crystals with large spin-polarization ratio, high Curie temperature and large magnetic anisotropic energy is one key to develop next-generation spintronic nanodevices. Here, 2D FeSi nanosheet, one counterpart of Hapkeite mineral discovered in meteorite with novel magnetism is proposed on the basis of first-principles calculations. The 2D FeSi crystal has a slightly buckled triangular lattice with planar hexacoordinated Si and Fe atoms. The spin-polarized calculations with hybrid HSE06 function method indicate that 2D FeSi is a ferromagnetic half metal at its ground state with 100% spin-polarization ratio at Fermi energy level. The phonon spectrum calculation and ab initio molecular dynamic simulation shows that 2D FeSi crystal has a high thermodynamic stability and its 2D lattice can be retained at the temperature up to 1200 K. Monte Carlo simulations based on the Ising model predict a Curie temperature over 780 K in 2D FeSi crystal, which can be further tuned by applying a biaxial strain. Moreover, 2D structure and strong in-plane Fe-Fe interaction endow FeSi nanosheet sizable magnetocrystalline anisotropy energy with the magnitude of at least two orders larger than those of Fe, Co and Ni bulks. These novel magnetic properties render the 2D FeSi crystal a very promising material for developing practical spintronic nanodevices.

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Section: Methodsmentioning

confidence: 99%

Room-Temperature Ferromagnetism in Two-Dimensional Fe₂Si Nanosheet with Enhanced Spin-Polarization Ratio

et al. 2017

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“…[7][8][9][10] The emergence of magnetism in 2D materials usually needs external electric eld, edgefunctionalizing, vacancy, defect, strain and doping. 8,11,12 Experimentally, substitutional doping has been proved to be Fig. 1 The schemes of density of states n(E) as a function of energy E for (a) a half-metal and (b) a half-semiconductor.…”

Section: Introductionmentioning

confidence: 99%

Half-metals and half-semiconductors in a transition metal doped SnSe₂ monolayer: a first-principles study

Han

Feng

et al. 2017

RSC Adv.

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“…It has been shown that the valance of Ni can undergo progressive oxidation from Ni II to Ni III/IV , [26][27][28] which promotes the O 2 generation rate greatly, and the promotional mechanism of Ni(OH) 2 for photocatalytic OER coupled with TiO 2 has been confirmed. [29] Thus, Ni(OH) 2 is suitable for the optimal O 2 evolution. [29] Thus, Ni(OH) 2 is suitable for the optimal O 2 evolution.…”

Section: Black Phosphorus-based Compound With Few Layers For Photocatmentioning

confidence: 99%

“…Then, a photoassisted approach for loading BP on the surface of Ni(OH) 2 was developed as shown in Figure S1. [26][27][28][29] During above multistep reaction processes, BP in the solution migrates to the surface of Ni(OH) 2 , where it is loaded tightly because of the interaction resulting from the oxidation of Ni II to Ni III/IV by the holes of BP ( Figure S3 and S4). After that, the mixture was irradiated under light irradiation, BP would produce electrons and holes, which then reduced protons to H 2 and oxidized water to O 2 ( Figure S2), respectively.…”

Section: Black Phosphorus-based Compound With Few Layers For Photocatmentioning

confidence: 99%

Black Phosphorus‐Based Compound with Few Layers for Photocatalytic Water Oxidation

Yan

Kong

et al. 2018

ChemCatChem

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Although black phosphorus (BP) is an interesting 2D nanosheet material with a high hole mobility, its application in the photocatalytic water oxidation for O 2 evolution is not reported yet. Herein the use of BP coupled with a reductive hydroxide, Ni(OH) 2 , is reported for the first time. The developed photoassisted process confirms that the BP XPS measurements confirm that the oxidation state of BP is reduced through the photo-assisted loading method. The obtained PÀNi(OH) 2 samples present the steady and efficient photocatalytic water splitting for O 2 generation. Under the simulated sunlight irradiation in 0.1 M Na 2 S 2 O 4 solution, the O 2 generation rate can reach up to 15.7 mmol/(g catalyst *h) or 224.3 mmol/(g BP *h). The density functional theory (DFT) calculation suggests that the electrons and holes move to surface of BP and Ni(OH) 2 , respectively. The merit of self-polarization of PÀNi(OH) 2 ensures the stability of BP and achieves the photocatalytic O 2 generation from water.The importance of photocatalysis in the solar-to-chemical energy converison is widely confirmed and the structure of the studied materials (metal-semiconductor and semiconductorsemiconductor, etc.) plays a crucial role. [1-10] On the compound system, a heterojunction is always used to promote the photogenerated carriers separation and favor the migration across the interface. [7][8][9][10] Moreover, in order to reach a new equilibrium, the different work functions of the components induce the relocation of the Fermi levels. During these processes, the redistribution of the free carriers i. e. electrons and holes to different sides of the semiconductors leads to the formation of one intermediate region, which is named as the built-in electric field. [5][6][7][8][9][10] Under the illumination of incident light, the heterojunction will generate photogenerated electron-hole pairs, which are separated by the field and then move to the different sites to participate in reactions, thus the enhanced photocatalytic activity will be obtained. Furthermore, a few layered heterojunction structure will reduce the migration distance and then decrease the recombination, thus enhancing the final photocatalytic activity of the system.Black phosphorous (BP) is an interesting material with the high hole carrier mobility of ca. 105 cm 2 /V/s, [11][12][13][14][15][16][17][18][19][20] wide range of thickness-dependent direct bandgap of range of 0.3 to 2.0 eV and strong optical absorption near infrared region. Therefore, BP-based samples have been applied working as one photocatalyst [16][17] or co-catalysts, [18] in the photocatalytic field, especially in the application of water splitting, which has been thought as the promising strategy to solve the future or near global energy and environmental issues. [21][22] Owing to the more positive than the oxidation potential of O 2 /H 2 O and the reduction potential of H + /H 2 , BP can only be used for photocatalytic water reduction to H 2 generation. [16][17][18] The band edge positions of BP semiconduc...

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Tunable band gap and magnetism of the two-dimensional nickel hydroxide

Abstract: The electronic structures and magnetic properties of two dimensional (2D) hexagonal Ni(OH)2 are explored based on first-principles calculations.

Cited by 25 publications

References 47 publications

Room-Temperature Ferromagnetism in Two-Dimensional Fe₂Si Nanosheet with Enhanced Spin-Polarization Ratio

Room-Temperature Ferromagnetism in Two-Dimensional Fe₂Si Nanosheet with Enhanced Spin-Polarization Ratio

Half-metals and half-semiconductors in a transition metal doped SnSe₂ monolayer: a first-principles study

Black Phosphorus‐Based Compound with Few Layers for Photocatalytic Water Oxidation

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Tunable band gap and magnetism of the two-dimensional nickel hydroxide

Abstract: The electronic structures and magnetic properties of two dimensional (2D) hexagonal Ni(OH)2 are explored based on first-principles calculations.

Cited by 25 publications

References 47 publications

Room-Temperature Ferromagnetism in Two-Dimensional Fe2Si Nanosheet with Enhanced Spin-Polarization Ratio

Room-Temperature Ferromagnetism in Two-Dimensional Fe2Si Nanosheet with Enhanced Spin-Polarization Ratio

Half-metals and half-semiconductors in a transition metal doped SnSe2 monolayer: a first-principles study

Black Phosphorus‐Based Compound with Few Layers for Photocatalytic Water Oxidation

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Product

Resources

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Room-Temperature Ferromagnetism in Two-Dimensional Fe₂Si Nanosheet with Enhanced Spin-Polarization Ratio

Room-Temperature Ferromagnetism in Two-Dimensional Fe₂Si Nanosheet with Enhanced Spin-Polarization Ratio

Half-metals and half-semiconductors in a transition metal doped SnSe₂ monolayer: a first-principles study