Tunable Photocatalytic Properties of Planar GaN/GeC Hetero-Bilayer: Production of H₂ Fuel

Khan, Md. Sakib Hasan; Islam, Md. Rafiqul; Islam, Md. Shahidul; Mehedi, Ibrahim M.; Hasan, Md. Tanvir

doi:10.1109/access.2020.3037036

Cited by 21 publications

(13 citation statements)

References 45 publications

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“…Generally, some criteria need to be met for photocatalytic H 2 production by the water-splitting process in semiconductors 34 : (i) The energy of the conduction band edge (CBE) must be set to a value greater or equal to − 4.44 eV from the vacuum (reduction potential) for creating hydrogen by a reduction reaction (H + /H 2 ), (ii) The energy of the valence band edge (VBE) must be set to a value lower or at least equal to − 5.67 eV from the vacuum (oxidation potential) to produce oxygen by oxidation reaction of water (O 2 /H 2 O), (iii) The semiconductor material must maintain a bandgap of at least ~ 1.23 eV, (iv) In the near-ultraviolet (UV) and visible solar spectrum, it must have prominent absorption peaks to utilize much of the energy spectrum, and (v) The materials should preserve a broad surface to volume ratio to enhance the photocatalysis process and to promote H 2 formation.…”

Section: Resultsmentioning

confidence: 99%

“…Prior investigations with vdWHs, including BP/GaN 31 , ZnO/MoS 2 32 , GaN/GeC 33 , 34 , ZnO/WSe 2 35 , blue phosphorene/g-GaN 36 , graphene/g-C 3 N 4 37 , CdO/CdS 38 , h -BN/C 2 N 39 , ZnO/GeC 40 , and blue phosphorene/MoS 2 41 , have outlined some promising optoelectronic features. These vdWHs demonstrate a highly tunable bandgap, large absorption coefficient, efficient isolation of the carrier, and contingent stacking tunability resulting in improved photocatalytic operations.…”

Section: Introductionmentioning

confidence: 99%

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Superior tunable photocatalytic properties for water splitting in two dimensional GeC/SiC van der Waals heterobilayers

Islam

Mitul

et al. 2021

Sci Rep

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The photocatalytic characteristics of two-dimensional (2D) GeC-based van der Waals heterobilayers (vdW-HBL) are systematically investigated to determine the amount of hydrogen (H2) fuel generated by water splitting. We propose several vdW-HBL structures consisting of 2D-GeC and 2D-SiC with exceptional and tunable optoelectronic properties. The structures exhibit a negative interlayer binding energy and non-negative phonon frequencies, showing that the structures are dynamically stable. The electronic properties of the HBLs depend on the stacking configuration, where the HBLs exhibit direct bandgap values of 1.978 eV, 2.278 eV, and 2.686 eV. The measured absorption coefficients for the HBLs are over ~ 105 cm−1, surpassing the prevalent conversion efficiency of optoelectronic materials. In the absence of external strain, the absorption coefficient for the HBLs reaches around 1 × 106 cm−1. With applied strain, absorption peaks are increased to ~ 3.5 times greater in value than the unstrained HBLs. Furthermore, the HBLs exhibit dynamically controllable bandgaps via the application of biaxial strain. A decrease in the bandgap occurs for both the HBLs when applied biaxial strain changes from the compressive to tensile strain. For + 4% tensile strain, the structure I become unsuitable for photocatalytic water splitting. However, in the biaxial strain range of − 6% to + 6%, both structure II and structure III have a sufficiently higher kinetic potential for demonstrating photocatalytic water-splitting activity in the region of UV to the visible in the light spectrum. These promising properties obtained for the GeC/SiC vdW heterobilayers suggest an application of the structures could boost H2 fuel production via water splitting.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Superior tunable photocatalytic properties for water splitting in two dimensional GeC/SiC van der Waals heterobilayers

Islam

Mitul

et al. 2021

Sci Rep

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“…Recently, electronic structure, charge transfer, and optical properties of GaN-GeC van der Waals heterostructures have been investigated using first-principle calculations; results suggest optical absorption in the visible region, which indicates that this is a promising material for photocatalytic applications [38]. In addition, tunable photocatalysis properties of GaN/GeC have been used for the production of H 2 fuel [39], water splitting, and solar energy conversion. e development of new materials involves property investigation in order to reach a real application.…”

Section: Introductionmentioning

confidence: 99%

Zinc-Blende GeC Stabilized on GaN (001): An Ab Initio Study

Camacho-García

Ruiz-Peralta

Hernández-Cocoletzi

et al. 2022

Advances in Condensed Matter Physics

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First-principle calculations have been performed to explore the initial stages of the zinc blende-like germanium carbide epitaxial growth on the gallium nitride (001)-(2 × 2) surface. First, we studied the Ge/C monolayer adsorption and incorporation at high symmetry sites. Results show that the adsorptions at the top and hcp1 sites are the most stable structures of C and Ge, respectively. Different terminated surfaces were used on the GeC epitaxial growth. According to the surface formation energies, only the first two bilayers are stable; therefore, the GeC epitaxial growth is favorable only under N-rich conditions on a Ge-terminated surface and with Ge bilayers terminated. In addition, it is demonstrated that GeC bilayers on the C-terminated surfaces are unstable and preclude the epitaxial growth. Electronic properties have been investigated by calculating the density of states (DOS) and the projected density of states (PDOS) of the most favorable structures.

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“…However, the spatial carrier separation, another key requirement for PWS cannot be acquired by only 2D materials. Here, comes another alluring concept, vdW stacked layered materials, as with the properties like 2D materials, they also have bandgap tunability due to stacking patterns, spatial carrier separation capability, and superior optical absorption [14], [15]. With the advent of nanotechnology, emergent materials, precisely, graphene, 2D oxides, 2D transition metals dichalcogenides (TMDs), and 2D group III-V are experimentally realized and unleashed the astonishingly unique properties of the materials [12], [16], [17].…”

Section: Introductionmentioning

confidence: 99%

“…It is also experimentally realized [24], [27]. Moreover, the vdW concept of 2D GaN is widely used as direct-Z scheme type-II bandgap photocatalysts for water splitting [15], [28]- [30]. Some of the shreds of evidence are compiled in TABLE I.…”

Section: Introductionmentioning

confidence: 99%

Potential Visible-Light Driven PtO₂/GaN vdW Hetero-Bilayer Photocatalysts for Water Splitting Using First-Principles

Khan

Islam

et al. 2021

IEEE Access

Self Cite

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Novel two-dimensional (2D) PtO2/GaN van der Waals (vdW) hetero-bilayers (HBL) are studied here for photocatalytic water splitting (PWS) application under first-principles density functional theory (DFT). We proposed six HBLs due to the atomic orientational variations and two of them are found dynamically stable confirmed by phonon dispersion curves. The two stable HBLs, HBL1, and HBL6 also show negative binding energy depicted by the interlayer distance-dependent binding energy curves. Among them, HBL1 has the lowest binding energy, suggesting the exothermic practicability of the material. Electronically both materials show a visible ranged indirect bandgap of ~2.65 (2.69) eV for HBL 1 (HBL6), lowered by ~2 times compared to their intrinsic constituents (2D PtO2, 2D GaN). The bandgaps also have type-II band orientation, which is highly required for efficient spatial carrier separation in photocatalytic water splitting (PWS) applications. The optical properties of the HBLs were also calculated, and it's found that the HBLs have ~2×10 5 cm -1 of perovskite material-like absorption coefficient in the visible spectrum, a key requirement for efficient photocatalysis. Reflectivity is as low as ~7 % in the visible spectrum, suggesting the low-loss nature of the materials. Photocatalytic band-edges with type-II band alignments show sufficient kinetic overpotential for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in both HBLs, suggesting effective water-splitting capacity. Moreover, we have explored the biaxial strain-induced tunability of the electronic bandgap, absorption coefficients, and photocatalytic band edges. They all found responsive due to homogeneous biaxial strain and show bandgap-lowering, absorption coefficient visible shifting, and band-edges tuning from compressive to tensile strains in the -6 % to +6% range. These studies suggest that the novel PtO2/GaN vdW layered material can be a probable efficient material for visible-lightdriven photocatalytic water-splitting technology.INDEX TERMS 2D PtO2/GaN, hetero-bilayer, Van der Waals (vdW) concept, first-principles density functional theory (DFT), optoelectronic property, photocatalytic water splitting.

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Tunable Photocatalytic Properties of Planar GaN/GeC Hetero-Bilayer: Production of H₂ Fuel

Cited by 21 publications

References 45 publications

Superior tunable photocatalytic properties for water splitting in two dimensional GeC/SiC van der Waals heterobilayers

Superior tunable photocatalytic properties for water splitting in two dimensional GeC/SiC van der Waals heterobilayers

Zinc-Blende GeC Stabilized on GaN (001): An Ab Initio Study

Potential Visible-Light Driven PtO₂/GaN vdW Hetero-Bilayer Photocatalysts for Water Splitting Using First-Principles

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